上下文，存储内部存储器并从中读取
Context, storing internal memory and reading from it
您好，我对行 productLookup(productId, Contexto) 中的上下文有疑问，我没弄对。
我想做的是当我通过网络从数据库中获取数据时，我还想将对象的 ID 传递给 productLookup 函数以下载关联的 jpg并将其保存在内部存储器中。不知道为什么这样做是最好的。如果你们有任何建议，请随时告诉我！
package com.example.proyectoprueba;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.loopj.android.http.AsyncHttpClient;
import com.loopj.android.http.AsyncHttpResponseHandler;
import com.loopj.android.http.RequestParams;
public class prueba extends ActionBarActivity{
// DB Class to perform DB related operations
DBController controller = new DBController(this);
// Progress Dialog Object
ProgressDialog prgDialog;
HashMap<String, String> queryValues;
@Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.lista);
ArrayList<HashMap<String, String>> platoList = controller.getAllPlatos();
// If users exists in SQLite DB
if (platoList.size() != 0) {
// Set the User Array list in ListView
ListAdapter adapter = new SimpleAdapter(prueba.this, platoList, R.layout.itemlista, new String[] {
"platoId", "platoNombre", "platoDescripcion", "platoPrecio" }, new int[] { R.id.codigo, R.id.nombre, R.id.descripcion, R.id.precio });
ListView myList = (ListView) findViewById(R.id.listaplatos);
myList.setAdapter(adapter);
}
// Initialize Progress Dialog properties
prgDialog = new ProgressDialog(this);
prgDialog.setMessage("Transferring Data from Remote MySQL DB and Syncing SQLite. Please wait...");
prgDialog.setCancelable(false);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public boolean onOptionsItemSelected(MenuItem item) {
Intent intent;
switch (item.getItemId()){
case R.id.entremeses:
intent =new Intent(this,prueba.class);
this.startActivity(intent);
break;
case R.id.arrocesypasta:
intent=new Intent(this,prueba.class);
this.startActivity(intent);
break;
case R.id.bebidas:
intent=new Intent(this,prueba.class);
this.startActivity(intent);
break;
case R.id.refresh:
// Transfer data from remote MySQL DB to SQLite on Android and perform Sync
syncSQLiteMySQLDB();
return true;
}
return super.onOptionsItemSelected(item);
}
// Method to Sync MySQL to SQLite DB
public void syncSQLiteMySQLDB() {
// Create AsycHttpClient object
AsyncHttpClient client = new AsyncHttpClient();
// Http Request Params Object
RequestParams params = new RequestParams();
// Show ProgressBar
prgDialog.show();
// Make Http call to getusers.php
client.post("http://restaurantechinaimperial.com/mysqlsqlitesync/getplatos.php", params, new AsyncHttpResponseHandler() {
@Override
public void onSuccess(String response) {
// Hide ProgressBar
prgDialog.hide();
// Update SQLite DB with response sent by getusers.php
updateSQLite(response);
}
// When error occured
@Override
public void onFailure(int statusCode, Throwable error, String content) {
// TODO Auto-generated method stub
// Hide ProgressBar
prgDialog.hide();
if (statusCode == 404) {
Toast.makeText(getApplicationContext(), "Requested resource not found", Toast.LENGTH_LONG).show();
} else if (statusCode == 500) {
Toast.makeText(getApplicationContext(), "Something went wrong at server end", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getApplicationContext(), "Unexpected Error occcured! [Most common Error: Device might not be connected to Internet]",
Toast.LENGTH_LONG).show();
}
}
});
}
public void updateSQLite(String response){
ArrayList<HashMap<String, String>> platosynclist;
platosynclist = new ArrayList<HashMap<String, String>>();
// Create GSON object
Gson gson = new GsonBuilder().create();
try {
// Extract JSON array from the response
JSONArray arr = new JSONArray(response);
System.out.println(arr.length());
// If no of array elements is not zero
if(arr.length() != 0){
// Loop through each array element, get JSON object which has userid and username
for (int i = 0; i < arr.length(); i++) {
// Get JSON object
JSONObject obj = (JSONObject) arr.get(i);
System.out.println(obj.get("platoId"));
System.out.println(obj.get("platoNombre"));
System.out.println(obj.get("platoDescripcion"));
System.out.println(obj.get("platoCategoria"));
System.out.println(obj.get("platoCaracteristicas"));
System.out.println(obj.get("platoPrecio"));
// DB QueryValues Object to insert into SQLite
queryValues = new HashMap<String, String>();
// Add userID extracted from Object
queryValues.put("platoId", obj.get("platoId").toString());
// Add userName extracted from Object
queryValues.put("platoNombre", obj.get("platoNombre").toString());
// Add userID extracted from Object
queryValues.put("platoDescripcion", obj.get("platoDescripcion").toString());
// Add userName extracted from Object
queryValues.put("platoCategoria", obj.get("platoCategoria").toString());
// Add userID extracted from Object
queryValues.put("platoCaracteristicas", obj.get("platoCaracteristicas").toString());
// Add userName extracted from Object
queryValues.put("platoPrecio", obj.get("platoPrecio").toString());
// Insert Plato into SQLite DB
controller.insertPlato(queryValues);
HashMap<String, String> map = new HashMap<String, String>();
// Add status for each plato in Hashmap
map.put("Id", obj.get("platoId").toString());
map.put("status", "1");
//I made the call here... it's right they why I did it?
platosynclist.add(map);
String productId=map.get("platoId");
try {
productLookup(productId);
} catch (IOException e) {
e.printStackTrace();
}
}
// Inform Remote MySQL DB about the completion of Sync activity by passing Sync status of Users
updateMySQLSyncSts(gson.toJson(platosynclist));
// Reload the Main Activity
reloadActivity();
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
// Method to inform remote MySQL DB about completion of Sync activity
public void updateMySQLSyncSts(String json) {
System.out.println(json);
AsyncHttpClient client = new AsyncHttpClient();
RequestParams params = new RequestParams();
params.put("syncsts", json);
// Make Http call to updatesyncsts.php with JSON parameter which has Sync statuses of Users
client.post("http://restaurantechinaimperial.com/mysqlsqlitesync/updatesyncstsplatos.php", params, new AsyncHttpResponseHandler() {
@Override
public void onSuccess(String response) {
Toast.makeText(getApplicationContext(), "MySQL DB has been informed about Sync activity", Toast.LENGTH_LONG).show();
}
@Override
public void onFailure(int statusCode, Throwable error, String content) {
Toast.makeText(getApplicationContext(), "Error Occured", Toast.LENGTH_LONG).show();
}
});
}
//下载图片
public String productLookup(String productID) throws IOException{
URL url = new URL("http://www.restaurantechinaimperial.com/menufotos/" + productID + ".jpg");
InputStream input = null;
FileOutputStream output = null;
try {
String outputName = productID + "-thumbnail.jpg";
input = url.openConnection().getInputStream();
output = getApplicationContext().openFileOutput(outputName, Context.MODE_PRIVATE);
int read;
byte[] data = new byte[1024];
while ((read = input.read(data)) != -1)
output.write(data, 0, read);
return outputName;
} finally {
if (output != null)
output.close();
if (input != null)
input.close();
}
}
public Bitmap decodeFile(File f){
try {
//decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeStream(new FileInputStream(f),null,o);
int scale=1;
//decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize=scale;
return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
} catch (FileNotFoundException e) {}
return null;
}
我的另一个问题是如何读取存储的图像，并将它们添加到列表视图中的对话框中。我想我必须使用
getFileStreamPath(文件名);
FileInputStream fi = new FileInputStream(文件路径);
但不确定。
从另一个 activity
中检索部分
// If users exists in SQLite DB
if (platoList.size() != 0) {
// Set the User Array list in ListView
final ListAdapter adapter = new SimpleAdapter(PlantillaChina.this, platoList, R.layout.itemlista, new String[] {
"platoId", "platoNombre", "platoDescripcion", "platoPrecio" }, new int[] {R.id.codigo, R.id.nombre, R.id.descripcion, R.id.precio });
ListView myList = (ListView) findViewById(R.id.listaplatos);
myList.setAdapter(adapter);
myList.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int
position, long id)
{
HashMap<String, String> obj = (HashMap<String, String>) adapter.getItem(position);
String platoId=(String) obj.get("platoId");
String name = (String) obj.get("platoNombre");
String description= (String) obj.get("platoDescripcion");
final Dialog dialog = new Dialog(PlantillaChina.this);
dialog.setContentView(R.layout.platocompleto);
dialog.setTitle(name);
ImageView image=(ImageView) dialog.findViewById(R.id.imagen);
// image.setImageResource(R.drawable.ic_launcher);
String fname=new File(getFilesDir(),platoId +".jpg").getAbsolutePath();
Bitmap Imagen=BitmapFactory.decodeFile(fname);
image.setImageBitmap(Imagen);
TextView texto=(TextView) dialog.findViewById(R.id.descripcionCompleta);
texto.setText(description);
dialog.getWindow().setBackgroundDrawable(new ColorDrawable(android.graphics.Color.BLACK));
dialog.show();
}
});
}
}
新错误日志
02-27 06:20:51.264: W/System.err(26443): java.io.FileNotFoundException: http://www.restaurantechinaimperial.com/menufotos/null.jpg
02-27 06:20:51.265: W/System.err(26443): at com.android.okhttp.internal.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:186)
02-27 06:20:51.266: W/System.err(26443): at com.example.proyectoprueba.prueba.productLookup(prueba.java:235)
02-27 06:20:51.266: W/System.err(26443): at com.example.proyectoprueba.prueba.updateSQLite(prueba.java:186)
02-27 06:20:51.267: W/System.err(26443): at com.example.proyectoprueba.prueba.onSuccess(prueba.java:122)
02-27 06:20:51.267: W/System.err(26443): at com.loopj.android.http.AsyncHttpResponseHandler.onSuccess(AsyncHttpResponseHandler.java:232)
02-27 06:20:51.268: W/System.err(26443): at com.loopj.android.http.AsyncHttpResponseHandler.onSuccess(AsyncHttpResponseHandler.java:220)
02-27 06:20:51.269: W/System.err(26443): at com.loopj.android.http.AsyncHttpResponseHandler.onSuccess(AsyncHttpResponseHandler.java:245)
02-27 06:20:51.270: W/System.err(26443): at com.loopj.android.http.AsyncHttpResponseHandler.handleMessage(AsyncHttpResponseHandler.java:365)
02-27 06:20:51.270: W/System.err(26443): at com.loopj.android.http.AsyncHttpResponseHandler$ResponderHandler.handleMessage(AsyncHttpResponseHandler.java:135)
02-27 06:20:51.271: W/System.err(26443): at android.os.Handler.dispatchMessage(Handler.java:110)
02-27 06:20:51.272: W/System.err(26443): at android.os.Looper.loop(Looper.java:193)
02-27 06:20:51.272: W/System.err(26443): at android.app.ActivityThread.main(ActivityThread.java:5323)
02-27 06:20:51.273: W/System.err(26443): at java.lang.reflect.Method.invokeNative(Native Method)
02-27 06:20:51.274: W/System.err(26443): at java.lang.reflect.Method.invoke(Method.java:515)
02-27 06:20:51.274: W/System.err(26443): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:825)
02-27 06:20:51.275: W/System.err(26443): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:641)
02-27 06:20:51.275: W/System.err(26443): at dalvik.system.NativeStart.main(Native Method)
来自方法 updateSQLITE 中的这个调用
HashMap<String, String> map = new HashMap<String, String>();
// Add status for each plato in Hashmap
map.put("Id", obj.get("platoId").toString());
map.put("status", "1");
//I made the call here... it's right they why I did it?
platosynclist.add(map);
String productId=map.get("platoId");
try {
productLookup(productId);
} catch (IOException e) {
e.printStackTrace();
}
}
首先将您的大型网络交易操作放入 AsynTask，然后更新您的 productLookup 方法，如下所示
public String productLookup(String productID) throws IOException{
URL url = new URL("http://www.samplewebsite.com/" + productID + ".jpg");
InputStream input = null;
FileOutputStream output = null;
try {
String outputName = productID + "-thumbnail.jpg";
input = url.openConnection().getInputStream();
output = getApplicationContext().openFileOutput(outputName, Context.MODE_PRIVATE);
int read;
byte[] data = new byte[1024];
while ((read = input.read(data)) != -1)
output.write(data, 0, read);
return outputName;
} finally {
if (output != null)
output.close();
if (input != null)
input.close();
}
}
然后调用此方法为
try {
productLookup(productId);
} catch (IOException e) {
e.printStackTrace();
}
最后使用下面给出的代码读取您保存的文件
private Bitmap decodeFile(File f){
try {
//decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeStream(new FileInputStream(f),null,o);
int scale=1;
//decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize=scale;
return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
} catch (FileNotFoundException e) {}
return null;
}
不要忘记添加写入外部存储权限。
在onCreate中添加以下代码
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build(); StrictMode.setThreadPolicy(policy);
要在对话框中显示图像，请将您的代码替换为 enter code here
Bitmap Imagen=decodeFile(new File(getFilesDir(),platoId +".jpg"));
image.setImageBitmap(Imagen);
首先你应该使用AsycnTask做任何http调用不要在应用程序主线程中做，这里是官方的link:
http://developer.android.com/reference/android/os/AsyncTask.html
以及存储后如何读取图像文件：
File myImage = new File(filePath);
try {
Bitmap pictureBitmap = MediaStore.Images.Media.getBitmap(activity.getContentResolver(), Uri.fromFile(myImage));
} catch (IOException e) {
e.printStackTrace();
}
BitmapDrawable picture = new BitmapDrawable(activity.getResources(), pictureBitmap);
并将外部存储权限添加到 Manifest。
您好，我对行 productLookup(productId, Contexto) 中的上下文有疑问，我没弄对。
我想做的是当我通过网络从数据库中获取数据时，我还想将对象的 ID 传递给 productLookup 函数以下载关联的 jpg并将其保存在内部存储器中。不知道为什么这样做是最好的。如果你们有任何建议，请随时告诉我！
package com.example.proyectoprueba;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.loopj.android.http.AsyncHttpClient;
import com.loopj.android.http.AsyncHttpResponseHandler;
import com.loopj.android.http.RequestParams;
public class prueba extends ActionBarActivity{
// DB Class to perform DB related operations
DBController controller = new DBController(this);
// Progress Dialog Object
ProgressDialog prgDialog;
HashMap<String, String> queryValues;
@Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.lista);
ArrayList<HashMap<String, String>> platoList = controller.getAllPlatos();
// If users exists in SQLite DB
if (platoList.size() != 0) {
// Set the User Array list in ListView
ListAdapter adapter = new SimpleAdapter(prueba.this, platoList, R.layout.itemlista, new String[] {
"platoId", "platoNombre", "platoDescripcion", "platoPrecio" }, new int[] { R.id.codigo, R.id.nombre, R.id.descripcion, R.id.precio });
ListView myList = (ListView) findViewById(R.id.listaplatos);
myList.setAdapter(adapter);
}
// Initialize Progress Dialog properties
prgDialog = new ProgressDialog(this);
prgDialog.setMessage("Transferring Data from Remote MySQL DB and Syncing SQLite. Please wait...");
prgDialog.setCancelable(false);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public boolean onOptionsItemSelected(MenuItem item) {
Intent intent;
switch (item.getItemId()){
case R.id.entremeses:
intent =new Intent(this,prueba.class);
this.startActivity(intent);
break;
case R.id.arrocesypasta:
intent=new Intent(this,prueba.class);
this.startActivity(intent);
break;
case R.id.bebidas:
intent=new Intent(this,prueba.class);
this.startActivity(intent);
break;
case R.id.refresh:
// Transfer data from remote MySQL DB to SQLite on Android and perform Sync
syncSQLiteMySQLDB();
return true;
}
return super.onOptionsItemSelected(item);
}
// Method to Sync MySQL to SQLite DB
public void syncSQLiteMySQLDB() {
// Create AsycHttpClient object
AsyncHttpClient client = new AsyncHttpClient();
// Http Request Params Object
RequestParams params = new RequestParams();
// Show ProgressBar
prgDialog.show();
// Make Http call to getusers.php
client.post("http://restaurantechinaimperial.com/mysqlsqlitesync/getplatos.php", params, new AsyncHttpResponseHandler() {
@Override
public void onSuccess(String response) {
// Hide ProgressBar
prgDialog.hide();
// Update SQLite DB with response sent by getusers.php
updateSQLite(response);
}
// When error occured
@Override
public void onFailure(int statusCode, Throwable error, String content) {
// TODO Auto-generated method stub
// Hide ProgressBar
prgDialog.hide();
if (statusCode == 404) {
Toast.makeText(getApplicationContext(), "Requested resource not found", Toast.LENGTH_LONG).show();
} else if (statusCode == 500) {
Toast.makeText(getApplicationContext(), "Something went wrong at server end", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getApplicationContext(), "Unexpected Error occcured! [Most common Error: Device might not be connected to Internet]",
Toast.LENGTH_LONG).show();
}
}
});
}
public void updateSQLite(String response){
ArrayList<HashMap<String, String>> platosynclist;
platosynclist = new ArrayList<HashMap<String, String>>();
// Create GSON object
Gson gson = new GsonBuilder().create();
try {
// Extract JSON array from the response
JSONArray arr = new JSONArray(response);
System.out.println(arr.length());
// If no of array elements is not zero
if(arr.length() != 0){
// Loop through each array element, get JSON object which has userid and username
for (int i = 0; i < arr.length(); i++) {
// Get JSON object
JSONObject obj = (JSONObject) arr.get(i);
System.out.println(obj.get("platoId"));
System.out.println(obj.get("platoNombre"));
System.out.println(obj.get("platoDescripcion"));
System.out.println(obj.get("platoCategoria"));
System.out.println(obj.get("platoCaracteristicas"));
System.out.println(obj.get("platoPrecio"));
// DB QueryValues Object to insert into SQLite
queryValues = new HashMap<String, String>();
// Add userID extracted from Object
queryValues.put("platoId", obj.get("platoId").toString());
// Add userName extracted from Object
queryValues.put("platoNombre", obj.get("platoNombre").toString());
// Add userID extracted from Object
queryValues.put("platoDescripcion", obj.get("platoDescripcion").toString());
// Add userName extracted from Object
queryValues.put("platoCategoria", obj.get("platoCategoria").toString());
// Add userID extracted from Object
queryValues.put("platoCaracteristicas", obj.get("platoCaracteristicas").toString());
// Add userName extracted from Object
queryValues.put("platoPrecio", obj.get("platoPrecio").toString());
// Insert Plato into SQLite DB
controller.insertPlato(queryValues);
HashMap<String, String> map = new HashMap<String, String>();
// Add status for each plato in Hashmap
map.put("Id", obj.get("platoId").toString());
map.put("status", "1");
//I made the call here... it's right they why I did it?
platosynclist.add(map);
String productId=map.get("platoId");
try {
productLookup(productId);
} catch (IOException e) {
e.printStackTrace();
}
}
// Inform Remote MySQL DB about the completion of Sync activity by passing Sync status of Users
updateMySQLSyncSts(gson.toJson(platosynclist));
// Reload the Main Activity
reloadActivity();
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
// Method to inform remote MySQL DB about completion of Sync activity
public void updateMySQLSyncSts(String json) {
System.out.println(json);
AsyncHttpClient client = new AsyncHttpClient();
RequestParams params = new RequestParams();
params.put("syncsts", json);
// Make Http call to updatesyncsts.php with JSON parameter which has Sync statuses of Users
client.post("http://restaurantechinaimperial.com/mysqlsqlitesync/updatesyncstsplatos.php", params, new AsyncHttpResponseHandler() {
@Override
public void onSuccess(String response) {
Toast.makeText(getApplicationContext(), "MySQL DB has been informed about Sync activity", Toast.LENGTH_LONG).show();
}
@Override
public void onFailure(int statusCode, Throwable error, String content) {
Toast.makeText(getApplicationContext(), "Error Occured", Toast.LENGTH_LONG).show();
}
});
}
//下载图片
public String productLookup(String productID) throws IOException{
URL url = new URL("http://www.restaurantechinaimperial.com/menufotos/" + productID + ".jpg");
InputStream input = null;
FileOutputStream output = null;
try {
String outputName = productID + "-thumbnail.jpg";
input = url.openConnection().getInputStream();
output = getApplicationContext().openFileOutput(outputName, Context.MODE_PRIVATE);
int read;
byte[] data = new byte[1024];
while ((read = input.read(data)) != -1)
output.write(data, 0, read);
return outputName;
} finally {
if (output != null)
output.close();
if (input != null)
input.close();
}
}
public Bitmap decodeFile(File f){
try {
//decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeStream(new FileInputStream(f),null,o);
int scale=1;
//decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize=scale;
return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
} catch (FileNotFoundException e) {}
return null;
}
我的另一个问题是如何读取存储的图像，并将它们添加到列表视图中的对话框中。我想我必须使用 getFileStreamPath(文件名); FileInputStream fi = new FileInputStream(文件路径);
但不确定。 从另一个 activity
中检索部分 // If users exists in SQLite DB
if (platoList.size() != 0) {
// Set the User Array list in ListView
final ListAdapter adapter = new SimpleAdapter(PlantillaChina.this, platoList, R.layout.itemlista, new String[] {
"platoId", "platoNombre", "platoDescripcion", "platoPrecio" }, new int[] {R.id.codigo, R.id.nombre, R.id.descripcion, R.id.precio });
ListView myList = (ListView) findViewById(R.id.listaplatos);
myList.setAdapter(adapter);
myList.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int
position, long id)
{
HashMap<String, String> obj = (HashMap<String, String>) adapter.getItem(position);
String platoId=(String) obj.get("platoId");
String name = (String) obj.get("platoNombre");
String description= (String) obj.get("platoDescripcion");
final Dialog dialog = new Dialog(PlantillaChina.this);
dialog.setContentView(R.layout.platocompleto);
dialog.setTitle(name);
ImageView image=(ImageView) dialog.findViewById(R.id.imagen);
// image.setImageResource(R.drawable.ic_launcher);
String fname=new File(getFilesDir(),platoId +".jpg").getAbsolutePath();
Bitmap Imagen=BitmapFactory.decodeFile(fname);
image.setImageBitmap(Imagen);
TextView texto=(TextView) dialog.findViewById(R.id.descripcionCompleta);
texto.setText(description);
dialog.getWindow().setBackgroundDrawable(new ColorDrawable(android.graphics.Color.BLACK));
dialog.show();
}
});
}
}
新错误日志
02-27 06:20:51.264: W/System.err(26443): java.io.FileNotFoundException: http://www.restaurantechinaimperial.com/menufotos/null.jpg
02-27 06:20:51.265: W/System.err(26443): at com.android.okhttp.internal.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:186)
02-27 06:20:51.266: W/System.err(26443): at com.example.proyectoprueba.prueba.productLookup(prueba.java:235)
02-27 06:20:51.266: W/System.err(26443): at com.example.proyectoprueba.prueba.updateSQLite(prueba.java:186)
02-27 06:20:51.267: W/System.err(26443): at com.example.proyectoprueba.prueba.onSuccess(prueba.java:122)
02-27 06:20:51.267: W/System.err(26443): at com.loopj.android.http.AsyncHttpResponseHandler.onSuccess(AsyncHttpResponseHandler.java:232)
02-27 06:20:51.268: W/System.err(26443): at com.loopj.android.http.AsyncHttpResponseHandler.onSuccess(AsyncHttpResponseHandler.java:220)
02-27 06:20:51.269: W/System.err(26443): at com.loopj.android.http.AsyncHttpResponseHandler.onSuccess(AsyncHttpResponseHandler.java:245)
02-27 06:20:51.270: W/System.err(26443): at com.loopj.android.http.AsyncHttpResponseHandler.handleMessage(AsyncHttpResponseHandler.java:365)
02-27 06:20:51.270: W/System.err(26443): at com.loopj.android.http.AsyncHttpResponseHandler$ResponderHandler.handleMessage(AsyncHttpResponseHandler.java:135)
02-27 06:20:51.271: W/System.err(26443): at android.os.Handler.dispatchMessage(Handler.java:110)
02-27 06:20:51.272: W/System.err(26443): at android.os.Looper.loop(Looper.java:193)
02-27 06:20:51.272: W/System.err(26443): at android.app.ActivityThread.main(ActivityThread.java:5323)
02-27 06:20:51.273: W/System.err(26443): at java.lang.reflect.Method.invokeNative(Native Method)
02-27 06:20:51.274: W/System.err(26443): at java.lang.reflect.Method.invoke(Method.java:515)
02-27 06:20:51.274: W/System.err(26443): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:825)
02-27 06:20:51.275: W/System.err(26443): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:641)
02-27 06:20:51.275: W/System.err(26443): at dalvik.system.NativeStart.main(Native Method)
来自方法 updateSQLITE 中的这个调用
HashMap<String, String> map = new HashMap<String, String>();
// Add status for each plato in Hashmap
map.put("Id", obj.get("platoId").toString());
map.put("status", "1");
//I made the call here... it's right they why I did it?
platosynclist.add(map);
String productId=map.get("platoId");
try {
productLookup(productId);
} catch (IOException e) {
e.printStackTrace();
}
}
首先将您的大型网络交易操作放入 AsynTask，然后更新您的 productLookup 方法，如下所示
public String productLookup(String productID) throws IOException{
URL url = new URL("http://www.samplewebsite.com/" + productID + ".jpg");
InputStream input = null;
FileOutputStream output = null;
try {
String outputName = productID + "-thumbnail.jpg";
input = url.openConnection().getInputStream();
output = getApplicationContext().openFileOutput(outputName, Context.MODE_PRIVATE);
int read;
byte[] data = new byte[1024];
while ((read = input.read(data)) != -1)
output.write(data, 0, read);
return outputName;
} finally {
if (output != null)
output.close();
if (input != null)
input.close();
}
}
然后调用此方法为
try {
productLookup(productId);
} catch (IOException e) {
e.printStackTrace();
}
最后使用下面给出的代码读取您保存的文件
private Bitmap decodeFile(File f){
try {
//decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeStream(new FileInputStream(f),null,o);
int scale=1;
//decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize=scale;
return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
} catch (FileNotFoundException e) {}
return null;
}
不要忘记添加写入外部存储权限。
在onCreate中添加以下代码
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build(); StrictMode.setThreadPolicy(policy);
要在对话框中显示图像，请将您的代码替换为 enter code here
Bitmap Imagen=decodeFile(new File(getFilesDir(),platoId +".jpg"));
image.setImageBitmap(Imagen);
首先你应该使用AsycnTask做任何http调用不要在应用程序主线程中做，这里是官方的link:
http://developer.android.com/reference/android/os/AsyncTask.html
以及存储后如何读取图像文件：
File myImage = new File(filePath);
try {
Bitmap pictureBitmap = MediaStore.Images.Media.getBitmap(activity.getContentResolver(), Uri.fromFile(myImage));
} catch (IOException e) {
e.printStackTrace();
}
BitmapDrawable picture = new BitmapDrawable(activity.getResources(), pictureBitmap);
并将外部存储权限添加到 Manifest。