Android 添加自定义列表视图
Android Add Above Custom Listview
我是 Android 的新手，所以努力学习最佳实践等，主要使用教程。
我让我的应用程序使用自定义列表视图执行我希望它执行的操作。我的问题是准确理解它是如何工作的，因为代码中没有实际的列表视图。
我想做的是在列表视图上方添加一个容器，但我尝试的一切似乎都不起作用，而且它是一个自定义适配器，我很难找到很多资源。
这是我的片段：
package info.androidhive.slidingmenu;
import android.annotation.TargetApi;
import android.app.ListFragment;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewStub;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.Toast;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class PhotosFragment extends ListFragment {
private static final String TAG = MainActivity.class.getSimpleName();
private List<ListViewItem> mItems; // ListView items list
JSONObject obj;
JSONArray stories;
class RequestTask extends AsyncTask<String, String, String> {
@Override
protected String doInBackground(String... uri) {
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response;
String responseString = null;
try {
response = httpclient.execute(new HttpGet(uri[0]));
StatusLine statusLine = response.getStatusLine();
if (statusLine.getStatusCode() == HttpStatus.SC_OK) {
ByteArrayOutputStream out = new ByteArrayOutputStream();
response.getEntity().writeTo(out);
out.close();
responseString = out.toString();
//Do anything with response..
Log.d(TAG, responseString);
} else {
//Closes the connection.
response.getEntity().getContent().close();
throw new IOException(statusLine.getReasonPhrase());
}
} catch (ClientProtocolException e) {
//TODO Handle problems..
Log.d(TAG, String.valueOf(e));
} catch (IOException e) {
//TODO Handle problems..
Log.d(TAG, String.valueOf(e));
}
return responseString;
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
Log.e(TAG, result);
try {
obj = new JSONObject(result);
stories = obj.getJSONArray("stories");
// initialize the items list
mItems = new ArrayList<ListViewItem>();
for (int i = 0; i < stories.length(); i++) {
JSONObject storyObj = stories.getJSONObject(i);
if (!storyObj.has("Advert")) {
newsStories newsStories = new newsStories();
newsStories.setTitle(storyObj.getString("subject"));
newsStories.setBody(storyObj.getString("body"));
mItems.add(new ListViewItem(newsStories.getTitle(), newsStories.getBody(), ""));
} else {
newsStories newsStories = new newsStories();
newsStories.setThumbnailUrl(storyObj.getString("Advert"));
mItems.add(new ListViewItem("", "", newsStories.getThumbnailUrl()));
}
// initialize and set the list adapter
setListAdapter(new ListViewDemoAdapter(getActivity(), mItems));
}
} catch (JSONException e) {
e.printStackTrace();
}
}
public class newsStories {
private String name, thumbnailUrl, body;
public String getTitle() {
return name;
}
public void setTitle(String name) {
this.name = name;
}
public String getBody() {
return body;
}
public void setBody(String body) {
this.body = body.substring(0, 150);
}
public String getThumbnailUrl() {
return thumbnailUrl;
}
public void setThumbnailUrl(String thumbnailUrl) {
//Check if thumbnail exists, if so take out spaces and replace with -
this.thumbnailUrl = thumbnailUrl;
}
}
}
@TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
// View importPanel = ((ViewStub) getActivity().findViewById(R.id.stub_import)).inflate();
new RequestTask().execute("http://www.myjsonurl.co.uk");
// remove the dividers from the ListView of the ListFragment
getListView().setDivider(null);
}
@Override
public void onListItemClick(ListView l, View v, int position, long id) {
// retrieve theListView item
ListViewItem item = mItems.get(position);
// do something
Toast.makeText(getActivity(), item.title, Toast.LENGTH_SHORT).show();
}
public class ListViewItem {
public final String title; // the text for the ListView item title
public final String description; // the text for the ListView item description
public final String adUrl;
//public final Drawable image;
public ListViewItem(String title, String description, String Advert_Url) {
Log.e("Advert:", Advert_Url);
if (Advert_Url != null && !Advert_Url.isEmpty()) {
String Advert = "http://alinktomyadvert.co.uk";
Log.e("TITLE: ", title);
this.title = "";
this.description = "";
this.adUrl = Advert;
} else {
this.title = title;
this.description = description;
this.adUrl = "";
}
}
}
}
如果有人能给我指出正确的方向，我将不胜感激。
编辑：
按照@Sufian 的建议，我现在有以下内容：
包 info.androidhive.slidingmenu;
import android.annotation.TargetApi;
import android.app.Fragment;
import android.app.ListFragment;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewStub;
import android.widget.ArrayAdapter;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class PhotosFragment extends Fragment {
public PhotosFragment(){}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_photos, container, false);
return rootView;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
new RequestTask().execute("http://www.myaddress.co.uk/app/index.php?Type=8&catid=7&userid=4");
Log.v("created", "onActivityCreated()");
setHasOptionsMenu(true);
//mProgressBar = (ProgressBar) getView().findViewById(R.id.progressBar);
ListView mListView = (ListView) getView().findViewById(R.id.listView2);
//mTvEmpty = (TextView) getView().findViewById(R.id.textView);
ArrayAdapter<ListViewItem> adapter = new ArrayAdapter<ListViewItem>(getActivity(), android.R.layout.simple_list_item_1, mItems);
// load your data to your mListView
mListView.setAdapter(adapter); //NULL POINTER
}
private static final String TAG = MainActivity.class.getSimpleName();
private List<ListViewItem> mItems; // ListView items list
JSONObject obj;
JSONArray stories;
//
class RequestTask extends AsyncTask<String, String, String> {
@Override
protected String doInBackground(String... uri) {
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response;
String responseString = null;
try {
response = httpclient.execute(new HttpGet(uri[0]));
StatusLine statusLine = response.getStatusLine();
if (statusLine.getStatusCode() == HttpStatus.SC_OK) {
ByteArrayOutputStream out = new ByteArrayOutputStream();
response.getEntity().writeTo(out);
out.close();
responseString = out.toString();
//Do anything with response..
Log.d(TAG, responseString);
} else {
//Closes the connection.
response.getEntity().getContent().close();
throw new IOException(statusLine.getReasonPhrase());
}
} catch (ClientProtocolException e) {
//TODO Handle problems..
Log.d(TAG, String.valueOf(e));
} catch (IOException e) {
//TODO Handle problems..
Log.d(TAG, String.valueOf(e));
}
return responseString;
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
Log.e(TAG, result);
try {
obj = new JSONObject(result);
stories = obj.getJSONArray("stories");
// initialize the items list
mItems = new ArrayList<ListViewItem>();
for (int i = 0; i < stories.length(); i++) {
JSONObject storyObj = stories.getJSONObject(i);
if (!storyObj.has("Advert")) {
newsStories newsStories = new newsStories();
newsStories.setTitle(storyObj.getString("subject"));
newsStories.setBody(storyObj.getString("body"));
mItems.add(new ListViewItem(newsStories.getTitle(), newsStories.getBody(), ""));
} else {
newsStories newsStories = new newsStories();
newsStories.setThumbnailUrl(storyObj.getString("Advert"));
mItems.add(new ListViewItem("", "", newsStories.getThumbnailUrl()));
}
// initialize and set the list adapter
//setListAdapter(new ListViewDemoAdapter(getActivity(), mItems));
}
} catch (JSONException e) {
e.printStackTrace();
}
}
public class newsStories {
private String name, thumbnailUrl, body;
public String getTitle() {
return name;
}
public void setTitle(String name) {
this.name = name;
}
public String getBody() {
return body;
}
public void setBody(String body) {
this.body = body.substring(0, 150);
}
public String getThumbnailUrl() {
return thumbnailUrl;
}
public void setThumbnailUrl(String thumbnailUrl) {
//Check if thumbnail exists, if so take out spaces and replace with -
this.thumbnailUrl = thumbnailUrl;
}
}
}
//
// @TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
// @Override
// public void onViewCreated(View view, Bundle savedInstanceState) {
// super.onViewCreated(view, savedInstanceState);
//
//
// // View importPanel = ((ViewStub) getActivity().findViewById(R.id.stub_import)).inflate();
// new RequestTask().execute("http://www.myjsonurl.co.uk");
// // remove the dividers from the ListView of the ListFragment
// getListView().setDivider(null);
// }
//
// @Override
// public void onListItemClick(ListView l, View v, int position, long id) {
// // retrieve theListView item
// ListViewItem item = mItems.get(position);
//
// // do something
// Toast.makeText(getActivity(), item.title, Toast.LENGTH_SHORT).show();
// }
//
public class ListViewItem {
public final String title; // the text for the ListView item title
public final String description; // the text for the ListView item description
public final String adUrl;
//public final Drawable image;
public ListViewItem(String title, String description, String Advert_Url) {
Log.e("Advert:", Advert_Url);
if (Advert_Url != null && !Advert_Url.isEmpty()) {
String Advert = "http://www.myaddress.co.uk/images/websitelogo.png?width=700&height=200";
Log.e("TITLE: ", title);
this.title = "";
this.description = "";
this.adUrl = Advert;
} else {
this.title = title;
this.description = description;
this.adUrl = "";
}
}
}
}
我现在在设置适配器命令上遇到空指针异常 - 我有点不确定从这里调试的位置。我假设这意味着列表为空？
编辑 2
Logcat:
01-19 05:27:30.371 1287-1287/info.androidhive.slidingmenu D/OpenGLRenderer﹕ Enabling debug mode 0
01-19 05:27:31.031 1287-1287/info.androidhive.slidingmenu I/Choreographer﹕ Skipped 60 frames! The application may be doing too much work on its main thread.
01-19 05:27:57.901 1287-1287/info.androidhive.slidingmenu V/created﹕ onActivityCreated()
01-19 05:28:08.271 1287-1287/info.androidhive.slidingmenu D/dalvikvm﹕ GC_FOR_ALLOC freed 326K, 9% free 4066K/4468K, paused 24ms, total 26ms
01-19 05:28:08.471 1287-1287/info.androidhive.slidingmenu D/AndroidRuntime﹕ Shutting down VM
01-19 05:28:08.471 1287-1287/info.androidhive.slidingmenu W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0xb3ac2ba8)
01-19 05:28:08.511 1287-1287/info.androidhive.slidingmenu E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: info.androidhive.slidingmenu, PID: 1287
java.lang.NullPointerException
at info.androidhive.slidingmenu.PhotosFragment$RequestTask.onPostExecute(PhotosFragment.java:130)
at info.androidhive.slidingmenu.PhotosFragment$RequestTask.onPostExecute(PhotosFragment.java:52)
at android.os.AsyncTask.finish(AsyncTask.java:632)
at android.os.AsyncTask.access0(AsyncTask.java:177)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:645)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
fragment_photos.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ProgressBar
style="?android:attr/progressBarStyleLarge"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/progressBar"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="190dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Text"
android:id="@+id/textView"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="63dp" />
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/listView2"
android:layout_below="@+id/progressBar"
android:layout_centerHorizontal="true" />
</RelativeLayout>
编辑 3
包 info.androidhive.slidingmenu;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.text.Html;
import android.text.Layout;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;
import com.squareup.picasso.Picasso;
import java.util.List;
public class ListViewDemoAdapter extends ArrayAdapter<PhotosFragment.ListViewItem> {
public ListViewDemoAdapter(Context context, List<PhotosFragment.ListViewItem> items) {
super(context, R.layout.listview_item, items);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
if(convertView == null) {
// inflate the GridView item layout
LayoutInflater inflater = LayoutInflater.from(getContext());
convertView = inflater.inflate(R.layout.listview_item, parent, false);
// initialize the view holder
viewHolder = new ViewHolder();
viewHolder.ivIcon = (ImageView) convertView.findViewById(R.id.ivIcon);
viewHolder.tvTitle = (TextView) convertView.findViewById(R.id.tvTitle);
viewHolder.tvDescription = (TextView) convertView.findViewById(R.id.tvDescription);
convertView.setTag(viewHolder);
} else {
// recycle the already inflated view
viewHolder = (ViewHolder) convertView.getTag();
}
// update the item view
PhotosFragment.ListViewItem item = getItem(position);
//viewHolder.ivIcon.setImageDrawable(item.image);
viewHolder.tvTitle.setText((Html.fromHtml(item.title)));
viewHolder.tvDescription.setText(Html.fromHtml(item.description));
if (!item.adUrl.isEmpty()) {
Picasso.with(getContext())
.load(item.adUrl)
.into(viewHolder.ivIcon);
viewHolder.ivIcon.setVisibility(viewHolder.ivIcon.VISIBLE);
viewHolder.ivIcon.setOnClickListener(new View.OnClickListener() {
//@Override
public void onClick(View v) {
Intent browserIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.myaddress.co.uk"));
getContext().startActivity(browserIntent);
}
});
}else {
viewHolder.ivIcon.setVisibility(viewHolder.ivIcon.GONE);
}
return convertView;
}
/**
* The view holder design pattern prevents using findViewById()
* repeatedly in the getView() method of the adapter.
*
* @see
*/
private static class ViewHolder {
ImageView ivIcon;
TextView tvTitle;
TextView tvDescription;
}
}
ListFragment 带有一个 ListView、一个 ProgressBar（显示直到你写 setListShown(true);）和一个 TextView（当 ListView没有项目。
如果您想在 ListView 之上添加任何内容，最简单的方法是将 ListFragment 替换为 Fragment 并扩充您自己的 XML。如下所示：
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_home, container, false);
}
并在 onActivityCreated() 中设置您的字段并填充数据，例如：
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
Log.v("created", "onActivityCreated()");
setHasOptionsMenu(true);
mProgressBar = (ProgressBar) getView().findViewById(R.id.progressBar1);
mListView = (ListView) getView().findViewById(R.id.listView1);
mTvEmpty = (TextView) getView().findViewById(R.id.tv_empty);
// load your data to your mListView
}
编辑：
将您的 onPostExecute() 更新为：
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
Log.e(TAG, result);
try {
obj = new JSONObject(result);
stories = obj.getJSONArray("stories");
// initialize the items list
mItems = new ArrayList<ListViewItem>();
for (int i = 0; i < stories.length(); i++) {
JSONObject storyObj = stories.getJSONObject(i);
if (!storyObj.has("Advert")) {
newsStories newsStories = new newsStories();
newsStories.setTitle(storyObj.getString("subject"));
newsStories.setBody(storyObj.getString("body"));
mItems.add(new ListViewItem(newsStories.getTitle(), newsStories.getBody(), ""));
}
else {
newsStories newsStories = new newsStories();
newsStories.setThumbnailUrl(storyObj.getString("Advert"));
mItems.add(new ListViewItem("", "", newsStories.getThumbnailUrl()));
}
// initialize and set the list adapter
//setListAdapter(new ListViewDemoAdapter(getActivity(), mItems));
}
//mProgressBar = (ProgressBar) getView().findViewById(R.id.progressBar);
ListView mListView = (ListView) getView().findViewById(R.id.listView2);
//mTvEmpty = (TextView) getView().findViewById(R.id.textView);
Log.d("mListView: ", String.valueOf(mListView));
ArrayAdapter<ListViewItem> adapter = new ArrayAdapter<ListViewItem>(getActivity(), android.R.layout.simple_list_item_1, mItems);
Log.d("Adapter: ", String.valueOf(adapter));
// load your data to your mListView
mListView.setAdapter(adapter);
}
catch (JSONException e) {
e.printStackTrace();
}
}
即使 mItems 为空，您也正在创建适配器（将它放在 catch 之后 运行 它总是）。
我是 Android 的新手，所以努力学习最佳实践等，主要使用教程。
我让我的应用程序使用自定义列表视图执行我希望它执行的操作。我的问题是准确理解它是如何工作的，因为代码中没有实际的列表视图。
我想做的是在列表视图上方添加一个容器，但我尝试的一切似乎都不起作用，而且它是一个自定义适配器，我很难找到很多资源。
这是我的片段：
package info.androidhive.slidingmenu;
import android.annotation.TargetApi;
import android.app.ListFragment;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewStub;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.Toast;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class PhotosFragment extends ListFragment {
private static final String TAG = MainActivity.class.getSimpleName();
private List<ListViewItem> mItems; // ListView items list
JSONObject obj;
JSONArray stories;
class RequestTask extends AsyncTask<String, String, String> {
@Override
protected String doInBackground(String... uri) {
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response;
String responseString = null;
try {
response = httpclient.execute(new HttpGet(uri[0]));
StatusLine statusLine = response.getStatusLine();
if (statusLine.getStatusCode() == HttpStatus.SC_OK) {
ByteArrayOutputStream out = new ByteArrayOutputStream();
response.getEntity().writeTo(out);
out.close();
responseString = out.toString();
//Do anything with response..
Log.d(TAG, responseString);
} else {
//Closes the connection.
response.getEntity().getContent().close();
throw new IOException(statusLine.getReasonPhrase());
}
} catch (ClientProtocolException e) {
//TODO Handle problems..
Log.d(TAG, String.valueOf(e));
} catch (IOException e) {
//TODO Handle problems..
Log.d(TAG, String.valueOf(e));
}
return responseString;
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
Log.e(TAG, result);
try {
obj = new JSONObject(result);
stories = obj.getJSONArray("stories");
// initialize the items list
mItems = new ArrayList<ListViewItem>();
for (int i = 0; i < stories.length(); i++) {
JSONObject storyObj = stories.getJSONObject(i);
if (!storyObj.has("Advert")) {
newsStories newsStories = new newsStories();
newsStories.setTitle(storyObj.getString("subject"));
newsStories.setBody(storyObj.getString("body"));
mItems.add(new ListViewItem(newsStories.getTitle(), newsStories.getBody(), ""));
} else {
newsStories newsStories = new newsStories();
newsStories.setThumbnailUrl(storyObj.getString("Advert"));
mItems.add(new ListViewItem("", "", newsStories.getThumbnailUrl()));
}
// initialize and set the list adapter
setListAdapter(new ListViewDemoAdapter(getActivity(), mItems));
}
} catch (JSONException e) {
e.printStackTrace();
}
}
public class newsStories {
private String name, thumbnailUrl, body;
public String getTitle() {
return name;
}
public void setTitle(String name) {
this.name = name;
}
public String getBody() {
return body;
}
public void setBody(String body) {
this.body = body.substring(0, 150);
}
public String getThumbnailUrl() {
return thumbnailUrl;
}
public void setThumbnailUrl(String thumbnailUrl) {
//Check if thumbnail exists, if so take out spaces and replace with -
this.thumbnailUrl = thumbnailUrl;
}
}
}
@TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
// View importPanel = ((ViewStub) getActivity().findViewById(R.id.stub_import)).inflate();
new RequestTask().execute("http://www.myjsonurl.co.uk");
// remove the dividers from the ListView of the ListFragment
getListView().setDivider(null);
}
@Override
public void onListItemClick(ListView l, View v, int position, long id) {
// retrieve theListView item
ListViewItem item = mItems.get(position);
// do something
Toast.makeText(getActivity(), item.title, Toast.LENGTH_SHORT).show();
}
public class ListViewItem {
public final String title; // the text for the ListView item title
public final String description; // the text for the ListView item description
public final String adUrl;
//public final Drawable image;
public ListViewItem(String title, String description, String Advert_Url) {
Log.e("Advert:", Advert_Url);
if (Advert_Url != null && !Advert_Url.isEmpty()) {
String Advert = "http://alinktomyadvert.co.uk";
Log.e("TITLE: ", title);
this.title = "";
this.description = "";
this.adUrl = Advert;
} else {
this.title = title;
this.description = description;
this.adUrl = "";
}
}
}
}
如果有人能给我指出正确的方向，我将不胜感激。
编辑：
按照@Sufian 的建议，我现在有以下内容：
包 info.androidhive.slidingmenu;
import android.annotation.TargetApi;
import android.app.Fragment;
import android.app.ListFragment;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewStub;
import android.widget.ArrayAdapter;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class PhotosFragment extends Fragment {
public PhotosFragment(){}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_photos, container, false);
return rootView;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
new RequestTask().execute("http://www.myaddress.co.uk/app/index.php?Type=8&catid=7&userid=4");
Log.v("created", "onActivityCreated()");
setHasOptionsMenu(true);
//mProgressBar = (ProgressBar) getView().findViewById(R.id.progressBar);
ListView mListView = (ListView) getView().findViewById(R.id.listView2);
//mTvEmpty = (TextView) getView().findViewById(R.id.textView);
ArrayAdapter<ListViewItem> adapter = new ArrayAdapter<ListViewItem>(getActivity(), android.R.layout.simple_list_item_1, mItems);
// load your data to your mListView
mListView.setAdapter(adapter); //NULL POINTER
}
private static final String TAG = MainActivity.class.getSimpleName();
private List<ListViewItem> mItems; // ListView items list
JSONObject obj;
JSONArray stories;
//
class RequestTask extends AsyncTask<String, String, String> {
@Override
protected String doInBackground(String... uri) {
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response;
String responseString = null;
try {
response = httpclient.execute(new HttpGet(uri[0]));
StatusLine statusLine = response.getStatusLine();
if (statusLine.getStatusCode() == HttpStatus.SC_OK) {
ByteArrayOutputStream out = new ByteArrayOutputStream();
response.getEntity().writeTo(out);
out.close();
responseString = out.toString();
//Do anything with response..
Log.d(TAG, responseString);
} else {
//Closes the connection.
response.getEntity().getContent().close();
throw new IOException(statusLine.getReasonPhrase());
}
} catch (ClientProtocolException e) {
//TODO Handle problems..
Log.d(TAG, String.valueOf(e));
} catch (IOException e) {
//TODO Handle problems..
Log.d(TAG, String.valueOf(e));
}
return responseString;
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
Log.e(TAG, result);
try {
obj = new JSONObject(result);
stories = obj.getJSONArray("stories");
// initialize the items list
mItems = new ArrayList<ListViewItem>();
for (int i = 0; i < stories.length(); i++) {
JSONObject storyObj = stories.getJSONObject(i);
if (!storyObj.has("Advert")) {
newsStories newsStories = new newsStories();
newsStories.setTitle(storyObj.getString("subject"));
newsStories.setBody(storyObj.getString("body"));
mItems.add(new ListViewItem(newsStories.getTitle(), newsStories.getBody(), ""));
} else {
newsStories newsStories = new newsStories();
newsStories.setThumbnailUrl(storyObj.getString("Advert"));
mItems.add(new ListViewItem("", "", newsStories.getThumbnailUrl()));
}
// initialize and set the list adapter
//setListAdapter(new ListViewDemoAdapter(getActivity(), mItems));
}
} catch (JSONException e) {
e.printStackTrace();
}
}
public class newsStories {
private String name, thumbnailUrl, body;
public String getTitle() {
return name;
}
public void setTitle(String name) {
this.name = name;
}
public String getBody() {
return body;
}
public void setBody(String body) {
this.body = body.substring(0, 150);
}
public String getThumbnailUrl() {
return thumbnailUrl;
}
public void setThumbnailUrl(String thumbnailUrl) {
//Check if thumbnail exists, if so take out spaces and replace with -
this.thumbnailUrl = thumbnailUrl;
}
}
}
//
// @TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
// @Override
// public void onViewCreated(View view, Bundle savedInstanceState) {
// super.onViewCreated(view, savedInstanceState);
//
//
// // View importPanel = ((ViewStub) getActivity().findViewById(R.id.stub_import)).inflate();
// new RequestTask().execute("http://www.myjsonurl.co.uk");
// // remove the dividers from the ListView of the ListFragment
// getListView().setDivider(null);
// }
//
// @Override
// public void onListItemClick(ListView l, View v, int position, long id) {
// // retrieve theListView item
// ListViewItem item = mItems.get(position);
//
// // do something
// Toast.makeText(getActivity(), item.title, Toast.LENGTH_SHORT).show();
// }
//
public class ListViewItem {
public final String title; // the text for the ListView item title
public final String description; // the text for the ListView item description
public final String adUrl;
//public final Drawable image;
public ListViewItem(String title, String description, String Advert_Url) {
Log.e("Advert:", Advert_Url);
if (Advert_Url != null && !Advert_Url.isEmpty()) {
String Advert = "http://www.myaddress.co.uk/images/websitelogo.png?width=700&height=200";
Log.e("TITLE: ", title);
this.title = "";
this.description = "";
this.adUrl = Advert;
} else {
this.title = title;
this.description = description;
this.adUrl = "";
}
}
}
}
我现在在设置适配器命令上遇到空指针异常 - 我有点不确定从这里调试的位置。我假设这意味着列表为空？
编辑 2
Logcat:
01-19 05:27:30.371 1287-1287/info.androidhive.slidingmenu D/OpenGLRenderer﹕ Enabling debug mode 0
01-19 05:27:31.031 1287-1287/info.androidhive.slidingmenu I/Choreographer﹕ Skipped 60 frames! The application may be doing too much work on its main thread.
01-19 05:27:57.901 1287-1287/info.androidhive.slidingmenu V/created﹕ onActivityCreated()
01-19 05:28:08.271 1287-1287/info.androidhive.slidingmenu D/dalvikvm﹕ GC_FOR_ALLOC freed 326K, 9% free 4066K/4468K, paused 24ms, total 26ms
01-19 05:28:08.471 1287-1287/info.androidhive.slidingmenu D/AndroidRuntime﹕ Shutting down VM
01-19 05:28:08.471 1287-1287/info.androidhive.slidingmenu W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0xb3ac2ba8)
01-19 05:28:08.511 1287-1287/info.androidhive.slidingmenu E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: info.androidhive.slidingmenu, PID: 1287
java.lang.NullPointerException
at info.androidhive.slidingmenu.PhotosFragment$RequestTask.onPostExecute(PhotosFragment.java:130)
at info.androidhive.slidingmenu.PhotosFragment$RequestTask.onPostExecute(PhotosFragment.java:52)
at android.os.AsyncTask.finish(AsyncTask.java:632)
at android.os.AsyncTask.access0(AsyncTask.java:177)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:645)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
fragment_photos.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ProgressBar
style="?android:attr/progressBarStyleLarge"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/progressBar"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="190dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Text"
android:id="@+id/textView"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="63dp" />
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/listView2"
android:layout_below="@+id/progressBar"
android:layout_centerHorizontal="true" />
</RelativeLayout>
编辑 3
包 info.androidhive.slidingmenu;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.text.Html;
import android.text.Layout;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;
import com.squareup.picasso.Picasso;
import java.util.List;
public class ListViewDemoAdapter extends ArrayAdapter<PhotosFragment.ListViewItem> {
public ListViewDemoAdapter(Context context, List<PhotosFragment.ListViewItem> items) {
super(context, R.layout.listview_item, items);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
if(convertView == null) {
// inflate the GridView item layout
LayoutInflater inflater = LayoutInflater.from(getContext());
convertView = inflater.inflate(R.layout.listview_item, parent, false);
// initialize the view holder
viewHolder = new ViewHolder();
viewHolder.ivIcon = (ImageView) convertView.findViewById(R.id.ivIcon);
viewHolder.tvTitle = (TextView) convertView.findViewById(R.id.tvTitle);
viewHolder.tvDescription = (TextView) convertView.findViewById(R.id.tvDescription);
convertView.setTag(viewHolder);
} else {
// recycle the already inflated view
viewHolder = (ViewHolder) convertView.getTag();
}
// update the item view
PhotosFragment.ListViewItem item = getItem(position);
//viewHolder.ivIcon.setImageDrawable(item.image);
viewHolder.tvTitle.setText((Html.fromHtml(item.title)));
viewHolder.tvDescription.setText(Html.fromHtml(item.description));
if (!item.adUrl.isEmpty()) {
Picasso.with(getContext())
.load(item.adUrl)
.into(viewHolder.ivIcon);
viewHolder.ivIcon.setVisibility(viewHolder.ivIcon.VISIBLE);
viewHolder.ivIcon.setOnClickListener(new View.OnClickListener() {
//@Override
public void onClick(View v) {
Intent browserIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.myaddress.co.uk"));
getContext().startActivity(browserIntent);
}
});
}else {
viewHolder.ivIcon.setVisibility(viewHolder.ivIcon.GONE);
}
return convertView;
}
/**
* The view holder design pattern prevents using findViewById()
* repeatedly in the getView() method of the adapter.
*
* @see
*/
private static class ViewHolder {
ImageView ivIcon;
TextView tvTitle;
TextView tvDescription;
}
}
ListFragment 带有一个 ListView、一个 ProgressBar（显示直到你写 setListShown(true);）和一个 TextView（当 ListView没有项目。
如果您想在 ListView 之上添加任何内容，最简单的方法是将 ListFragment 替换为 Fragment 并扩充您自己的 XML。如下所示：
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_home, container, false);
}
并在 onActivityCreated() 中设置您的字段并填充数据，例如：
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
Log.v("created", "onActivityCreated()");
setHasOptionsMenu(true);
mProgressBar = (ProgressBar) getView().findViewById(R.id.progressBar1);
mListView = (ListView) getView().findViewById(R.id.listView1);
mTvEmpty = (TextView) getView().findViewById(R.id.tv_empty);
// load your data to your mListView
}
编辑：
将您的 onPostExecute() 更新为：
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
Log.e(TAG, result);
try {
obj = new JSONObject(result);
stories = obj.getJSONArray("stories");
// initialize the items list
mItems = new ArrayList<ListViewItem>();
for (int i = 0; i < stories.length(); i++) {
JSONObject storyObj = stories.getJSONObject(i);
if (!storyObj.has("Advert")) {
newsStories newsStories = new newsStories();
newsStories.setTitle(storyObj.getString("subject"));
newsStories.setBody(storyObj.getString("body"));
mItems.add(new ListViewItem(newsStories.getTitle(), newsStories.getBody(), ""));
}
else {
newsStories newsStories = new newsStories();
newsStories.setThumbnailUrl(storyObj.getString("Advert"));
mItems.add(new ListViewItem("", "", newsStories.getThumbnailUrl()));
}
// initialize and set the list adapter
//setListAdapter(new ListViewDemoAdapter(getActivity(), mItems));
}
//mProgressBar = (ProgressBar) getView().findViewById(R.id.progressBar);
ListView mListView = (ListView) getView().findViewById(R.id.listView2);
//mTvEmpty = (TextView) getView().findViewById(R.id.textView);
Log.d("mListView: ", String.valueOf(mListView));
ArrayAdapter<ListViewItem> adapter = new ArrayAdapter<ListViewItem>(getActivity(), android.R.layout.simple_list_item_1, mItems);
Log.d("Adapter: ", String.valueOf(adapter));
// load your data to your mListView
mListView.setAdapter(adapter);
}
catch (JSONException e) {
e.printStackTrace();
}
}
即使 mItems 为空，您也正在创建适配器（将它放在 catch 之后 运行 它总是）。