Loopj AsyncHttpClient - 控制 ArrayAdapter 内部处理程序的视图
Loopj AsyncHttpClient - control views on handler inside ArrayAdapter
我正在使用 AsyncHttpClient 的 loopj 从 Internet 获取图像文件并将其显示在典型的图像视图中。
我找到了名为 FileAsyncHttpClient 的便捷处理程序，并且我检查了以下简单代码的工作情况是否与我预期的一样。
public class MainActivity extends ActionBarActivity {
ImageView imgView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imgView = (ImageView) findViewById(R.id.imgView);
AsyncHttpClient client = new AsyncHttpClient();
client.get("http://www.some_image_url.png",
new FileAsyncHttpResponseHandler(this){
@Override
public void onFailure(int statusCode, Header[] headers, Throwable throwable, File response) {}
@Override
public void onSuccess(int statusCode, Header[] headers, File response) {
imgView.setImageBitmap(BitmapFactory.decodeFile(response.getPath()));
}
});
}
}
但是当我在ArrayAdpater class中使用此代码时，在Activity class中不使用此代码时，setImageBitmap(...) 不起作用。此外，似乎不允许任何视图控制，例如 setVisibility(...).
以下代码是有问题的代码。
public class MainActivity extends Activity {
private List<CustomClass> objectList = new ArrayList<CustomClass>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// ... make objectList from given data ... (omitted)
ArrayAdapter<CustomClass> adapter = new CustomListAdapter();
ListView list = (ListView) findViewById(R.id.customListView);
list.setAdapter(adapter);
}
private class CustomListAdapter extends ArrayAdapter<CustomClass> {
private View itemView;
ImageView imgView;
public MemberListAdapter() {
super(MainActivity.this, R.layout.custom_list, objectList);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
itemView = convertView;
if(itemView == null){
itemView = getLayoutInflater().inflate(R.layout.custom_list, parent, false);
}
CustomClass currentObj = objectList.get(position);
imgView = (ImageView) itemView.findViewById(R.id.imgView);
AsyncHttpClient client = new AsyncHttpClient();
client.get("http://www.some_image_url.png",
new FileAsyncHttpResponseHandler(this){
@Override
public void onFailure(int statusCode, Header[] headers, Throwable throwable, File response) {}
@Override
public void onSuccess(int statusCode, Header[] headers, File response) {
imgView.setImageBitmap(BitmapFactory.decodeFile(response.getPath()));
}
});
return itemView;
}
}
}
我不知道为什么这不起作用。请让我得到一个建议。谢谢。
p.s。我已经检查了适配器内部的控制视图，但在处理程序外部是可能的。
我试过你的代码，没有发现任何错误，但这是我的。 （我添加了一些增强功能，例如 ViewHolder 模式）。
主要activity。对不起一个大胖子class.
public class LoopJAsync extends AppCompatActivity {
@Override protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_loop_jasync);
ListView myListView = (ListView) findViewById(R.id.my_list_view);
List<MyObject> myObjectList = new ArrayList<>();
for (String imageUrl : ImageData.URLS) {
myObjectList.add(new MyObject(imageUrl));
}
ArrayAdapter<MyObject> adapter = new CustomListAdapter(myObjectList);
myListView.setAdapter(adapter);
}
private class MyObject {
public String url;
public MyObject(String url) {
this.url = url;
}
}
private class CustomListAdapter extends ArrayAdapter<MyObject> {
private View itemView;
private List<MyObject> myObjectList = Collections.emptyList();
public CustomListAdapter(List<MyObject> myObjectList) {
super(LoopJAsync.this, R.layout.row_loopj_test, myObjectList);
this.myObjectList = myObjectList;
}
@Override public View getView(int position, View convertView, ViewGroup parent) {
itemView = convertView;
if (convertView == null) {
LayoutInflater inflater = getLayoutInflater();
itemView = inflater.inflate(R.layout.row_loopj_test, null);
// configure view holder
ViewHolder viewHolder = new ViewHolder();
viewHolder.imageView = (ImageView) itemView.findViewById(R.id.image);
viewHolder.mProgressView = (ProgressBar) itemView.findViewById(R.id.progress);
itemView.setTag(viewHolder);
}
// fill data
final ViewHolder holder = (ViewHolder) itemView.getTag();
MyObject currentObj = myObjectList.get(position);
AsyncHttpClient client = new AsyncHttpClient();
// Show the progress circle and show the image
holder.mProgressView.setVisibility(View.VISIBLE);
holder.imageView.setVisibility(View.GONE);
client.get(currentObj.url, new FileAsyncHttpResponseHandler(LoopJAsync.this) {
@Override public void onFailure(int statusCode, Header[] headers, Throwable throwable,
File response) {
}
@Override public void onSuccess(int statusCode, Header[] headers, File response) {
// Hide the progress circle and show the image
holder.mProgressView.setVisibility(View.GONE);
holder.imageView.setVisibility(View.VISIBLE);
Log.i("success", " yup done. Look at status - " + statusCode);
holder.imageView.setImageBitmap(BitmapFactory.decodeFile(response.getPath()));
}
});
return itemView;
}
private class ViewHolder {
ProgressBar mProgressView;
ImageView imageView;
}
}
}
这里是 ImageData class.
// From Picasso
// https://github.com/square/picasso/blob/master/picasso-sample%2Fsrc%2Fmain%2Fjava%2Fcom%2Fexample%2Fpicasso%2FData.java
final class ImageData {
static final String BASE = "http://i.imgur.com/";
static final String EXT = ".jpg";
static final String[] URLS = {
BASE + "CqmBjo5" + EXT, BASE + "zkaAooq" + EXT, BASE + "0gqnEaY" + EXT,
BASE + "9gbQ7YR" + EXT, BASE + "aFhEEby" + EXT, BASE + "0E2tgV7" + EXT,
BASE + "P5JLfjk" + EXT, BASE + "nz67a4F" + EXT, BASE + "dFH34N5" + EXT,
BASE + "FI49ftb" + EXT, BASE + "DvpvklR" + EXT, BASE + "DNKnbG8" + EXT,
BASE + "yAdbrLp" + EXT, BASE + "55w5Km7" + EXT, BASE + "NIwNTMR" + EXT,
BASE + "DAl0KB8" + EXT, BASE + "xZLIYFV" + EXT, BASE + "HvTyeh3" + EXT,
BASE + "Ig9oHCM" + EXT, BASE + "7GUv9qa" + EXT, BASE + "i5vXmXp" + EXT,
BASE + "glyvuXg" + EXT, BASE + "u6JF6JZ" + EXT, BASE + "ExwR7ap" + EXT,
BASE + "Q54zMKT" + EXT, BASE + "9t6hLbm" + EXT, BASE + "F8n3Ic6" + EXT,
BASE + "P5ZRSvT" + EXT, BASE + "jbemFzr" + EXT, BASE + "8B7haIK" + EXT,
BASE + "aSeTYQr" + EXT, BASE + "OKvWoTh" + EXT, BASE + "zD3gT4Z" + EXT,
BASE + "z77CaIt" + EXT,
};
private ImageData() {
// No instances.
}
}
这是适配器行布局。
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<ProgressBar
android:id="@+id/progress"
style="?android:progressBarStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
tools:text="Hello World"
/>
<ImageView
android:id="@+id/image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:contentDescription="@string/title_activity_loop_jasync"
/>
</LinearLayout>
和主要布局。
<ListView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/my_list_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.yelinaung.playground.LoopJAsync"
/>
如果可以的话，我想提出的建议之一是利用图像加载库。他们可以优雅地处理图像下载和缓存。仅举几例，这些是流行的。
我正在使用 AsyncHttpClient 的 loopj 从 Internet 获取图像文件并将其显示在典型的图像视图中。
我找到了名为 FileAsyncHttpClient 的便捷处理程序，并且我检查了以下简单代码的工作情况是否与我预期的一样。
public class MainActivity extends ActionBarActivity {
ImageView imgView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imgView = (ImageView) findViewById(R.id.imgView);
AsyncHttpClient client = new AsyncHttpClient();
client.get("http://www.some_image_url.png",
new FileAsyncHttpResponseHandler(this){
@Override
public void onFailure(int statusCode, Header[] headers, Throwable throwable, File response) {}
@Override
public void onSuccess(int statusCode, Header[] headers, File response) {
imgView.setImageBitmap(BitmapFactory.decodeFile(response.getPath()));
}
});
}
}
但是当我在ArrayAdpater class中使用此代码时，在Activity class中不使用此代码时，setImageBitmap(...) 不起作用。此外，似乎不允许任何视图控制，例如 setVisibility(...).
以下代码是有问题的代码。
public class MainActivity extends Activity {
private List<CustomClass> objectList = new ArrayList<CustomClass>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// ... make objectList from given data ... (omitted)
ArrayAdapter<CustomClass> adapter = new CustomListAdapter();
ListView list = (ListView) findViewById(R.id.customListView);
list.setAdapter(adapter);
}
private class CustomListAdapter extends ArrayAdapter<CustomClass> {
private View itemView;
ImageView imgView;
public MemberListAdapter() {
super(MainActivity.this, R.layout.custom_list, objectList);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
itemView = convertView;
if(itemView == null){
itemView = getLayoutInflater().inflate(R.layout.custom_list, parent, false);
}
CustomClass currentObj = objectList.get(position);
imgView = (ImageView) itemView.findViewById(R.id.imgView);
AsyncHttpClient client = new AsyncHttpClient();
client.get("http://www.some_image_url.png",
new FileAsyncHttpResponseHandler(this){
@Override
public void onFailure(int statusCode, Header[] headers, Throwable throwable, File response) {}
@Override
public void onSuccess(int statusCode, Header[] headers, File response) {
imgView.setImageBitmap(BitmapFactory.decodeFile(response.getPath()));
}
});
return itemView;
}
}
}
我不知道为什么这不起作用。请让我得到一个建议。谢谢。
p.s。我已经检查了适配器内部的控制视图，但在处理程序外部是可能的。
我试过你的代码，没有发现任何错误，但这是我的。 （我添加了一些增强功能，例如 ViewHolder 模式）。
主要activity。对不起一个大胖子class.
public class LoopJAsync extends AppCompatActivity {
@Override protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_loop_jasync);
ListView myListView = (ListView) findViewById(R.id.my_list_view);
List<MyObject> myObjectList = new ArrayList<>();
for (String imageUrl : ImageData.URLS) {
myObjectList.add(new MyObject(imageUrl));
}
ArrayAdapter<MyObject> adapter = new CustomListAdapter(myObjectList);
myListView.setAdapter(adapter);
}
private class MyObject {
public String url;
public MyObject(String url) {
this.url = url;
}
}
private class CustomListAdapter extends ArrayAdapter<MyObject> {
private View itemView;
private List<MyObject> myObjectList = Collections.emptyList();
public CustomListAdapter(List<MyObject> myObjectList) {
super(LoopJAsync.this, R.layout.row_loopj_test, myObjectList);
this.myObjectList = myObjectList;
}
@Override public View getView(int position, View convertView, ViewGroup parent) {
itemView = convertView;
if (convertView == null) {
LayoutInflater inflater = getLayoutInflater();
itemView = inflater.inflate(R.layout.row_loopj_test, null);
// configure view holder
ViewHolder viewHolder = new ViewHolder();
viewHolder.imageView = (ImageView) itemView.findViewById(R.id.image);
viewHolder.mProgressView = (ProgressBar) itemView.findViewById(R.id.progress);
itemView.setTag(viewHolder);
}
// fill data
final ViewHolder holder = (ViewHolder) itemView.getTag();
MyObject currentObj = myObjectList.get(position);
AsyncHttpClient client = new AsyncHttpClient();
// Show the progress circle and show the image
holder.mProgressView.setVisibility(View.VISIBLE);
holder.imageView.setVisibility(View.GONE);
client.get(currentObj.url, new FileAsyncHttpResponseHandler(LoopJAsync.this) {
@Override public void onFailure(int statusCode, Header[] headers, Throwable throwable,
File response) {
}
@Override public void onSuccess(int statusCode, Header[] headers, File response) {
// Hide the progress circle and show the image
holder.mProgressView.setVisibility(View.GONE);
holder.imageView.setVisibility(View.VISIBLE);
Log.i("success", " yup done. Look at status - " + statusCode);
holder.imageView.setImageBitmap(BitmapFactory.decodeFile(response.getPath()));
}
});
return itemView;
}
private class ViewHolder {
ProgressBar mProgressView;
ImageView imageView;
}
}
}
这里是 ImageData class.
// From Picasso
// https://github.com/square/picasso/blob/master/picasso-sample%2Fsrc%2Fmain%2Fjava%2Fcom%2Fexample%2Fpicasso%2FData.java
final class ImageData {
static final String BASE = "http://i.imgur.com/";
static final String EXT = ".jpg";
static final String[] URLS = {
BASE + "CqmBjo5" + EXT, BASE + "zkaAooq" + EXT, BASE + "0gqnEaY" + EXT,
BASE + "9gbQ7YR" + EXT, BASE + "aFhEEby" + EXT, BASE + "0E2tgV7" + EXT,
BASE + "P5JLfjk" + EXT, BASE + "nz67a4F" + EXT, BASE + "dFH34N5" + EXT,
BASE + "FI49ftb" + EXT, BASE + "DvpvklR" + EXT, BASE + "DNKnbG8" + EXT,
BASE + "yAdbrLp" + EXT, BASE + "55w5Km7" + EXT, BASE + "NIwNTMR" + EXT,
BASE + "DAl0KB8" + EXT, BASE + "xZLIYFV" + EXT, BASE + "HvTyeh3" + EXT,
BASE + "Ig9oHCM" + EXT, BASE + "7GUv9qa" + EXT, BASE + "i5vXmXp" + EXT,
BASE + "glyvuXg" + EXT, BASE + "u6JF6JZ" + EXT, BASE + "ExwR7ap" + EXT,
BASE + "Q54zMKT" + EXT, BASE + "9t6hLbm" + EXT, BASE + "F8n3Ic6" + EXT,
BASE + "P5ZRSvT" + EXT, BASE + "jbemFzr" + EXT, BASE + "8B7haIK" + EXT,
BASE + "aSeTYQr" + EXT, BASE + "OKvWoTh" + EXT, BASE + "zD3gT4Z" + EXT,
BASE + "z77CaIt" + EXT,
};
private ImageData() {
// No instances.
}
}
这是适配器行布局。
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<ProgressBar
android:id="@+id/progress"
style="?android:progressBarStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
tools:text="Hello World"
/>
<ImageView
android:id="@+id/image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:contentDescription="@string/title_activity_loop_jasync"
/>
</LinearLayout>
和主要布局。
<ListView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/my_list_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.yelinaung.playground.LoopJAsync"
/>
如果可以的话，我想提出的建议之一是利用图像加载库。他们可以优雅地处理图像下载和缓存。仅举几例，这些是流行的。