我有应用程序，通过地址获取图像＆＃34; http://xn--e1aybc.xn--76-6kc1ag2ab9l.xn--p1ai/food.png＆＃34;（例如）来自服务器
public class MenuActivity extends Activity {
private static ArrayList<Products> myProducts;
ParseJSON parseJSON;
private static ArrayList <Bitmap> bm;
final String GetMenuUrl = "http://xn--e1aybc.xn--76-6kc1ag2ab9l.xn--p1ai/get_menu.php";
String City = "Moscow";
String NameCinema = "Avrora";
private ProgressDialog dialog;
private String response;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.menu);
init();
new RequestTask().execute(GetMenuUrl);
}
private void init(){
myProducts = new ArrayList<Products>();
parseJSON = new ParseJSON();
}
private void setAdapter(ArrayList<Products> products){
GridView grid;
for(int i = 0; i < myProducts.size(); i++){
try {
bm.add(downloadBitmap("http://xn--e1aybc.xn--76-6kc1ag2ab9l.xn--p1ai/food.png"));
} catch (IOException e) {
e.printStackTrace();
}
}
System.out.println("size == " + bm.size());
final ImageView imageView = (ImageView) findViewById(R.id.imageView);
SetImg("http://xn--e1aybc.xn--76-6kc1ag2ab9l.xn--p1ai/food.png",imageView);
System.out.println("size == " + bm.size());
CustomGrid adapter = new CustomGrid(MenuActivity.this, products, bm);
grid=(GridView)findViewById(R.id.grid);
grid.setAdapter(adapter);
grid.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
Toast.makeText(MenuActivity.this, "Продукт " + myProducts.get(position).getProductName() + " добавлен в корзину", Toast.LENGTH_SHORT).show();
}
});
}
private void SetImg(final String url,final ImageView v){
final ProgressDialog dialog = ProgressDialog.show(this, "Download",
"downloading");
dialog.show();
new Thread(new Runnable() {
@Override
public void run() {
try {
final Bitmap downloadBitma = downloadBitmap(url);
runOnUiThread(new Runnable() {
@Override
public void run() {
v.setImageBitmap(downloadBitma);
}
});
} catch (IOException e) {
e.printStackTrace();
} finally {
dialog.dismiss();
}
}
}).start();
}
private Bitmap downloadBitmap(String url) throws IOException {
HttpUriRequest request = new HttpGet(url.toString());
HttpClient httpClient = new DefaultHttpClient();
HttpResponse response = httpClient.execute(request);
StatusLine statusLine = response.getStatusLine();
int statusCode = statusLine.getStatusCode();
if (statusCode == 200) {
HttpEntity entity = response.getEntity();
byte[] bytes = EntityUtils.toByteArray(entity);
Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0,
bytes.length);
return bitmap;
} else {
throw new IOException("Download failed, HTTP response code "
+ statusCode + " - " + statusLine.getReasonPhrase());
}
}
class RequestTask extends AsyncTask<String, String, String> {
@Override
protected String doInBackground(String... params) {
try {
DefaultHttpClient hc = new DefaultHttpClient();
ResponseHandler<String> res = new BasicResponseHandler();
HttpPost postMethod = new HttpPost(params[0]);
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("city", City));
nameValuePairs.add(new BasicNameValuePair("name_cinema",NameCinema));
postMethod.setEntity(new UrlEncodedFormEntity(nameValuePairs));
response = hc.execute(postMethod, res);
parseJSON.parse(response.toString());
Log.d("response == ", response.toString());
myProducts = parseJSON.getObjects();
Log.d("firstProduc == ", myProducts.get(0).getProductName());
} catch (Exception e) {
System.out.println("Exp=" + e);
}
return null;
}
@Override
protected void onPostExecute(String result) {
if (dialog != null && dialog.isShowing())
dialog.dismiss();
ArrayList<String> products = new ArrayList<String>();
for(int i = 0 ; i < myProducts.size(); i++){
products.add(myProducts.get(i).getProductName());
}
if(products.size() != 0)
setAdapter(myProducts);
else Log.d("error", "can`t load");
super.onPostExecute(result);
}
@Override
protected void onPreExecute() {
dialog = new ProgressDialog(MenuActivity.this);
dialog.setMessage("Загружаюсь...");
dialog.setIndeterminate(true);
dialog.setCancelable(true);
dialog.show();
super.onPreExecute();
}
}
}
//将图像显示到gridview
public class CustomGrid extends BaseAdapter{
private Context mContext;
private final ArrayList<Products> web;
private final ArrayList<Bitmap> Imageid;
public CustomGrid(Context c,ArrayList<Products> web,ArrayList<Bitmap>Imageid ) {
mContext = c;
this.Imageid = Imageid;
this.web = web;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return web.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return null;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
View grid;
LayoutInflater inflater = (LayoutInflater) mContext
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (convertView == null) {
grid = new View(mContext);
grid = inflater.inflate(R.layout.rowlayout, null);
TextView textView = (TextView) grid.findViewById(R.id.grid_text);
TextView textDescr = (TextView) grid.findViewById(R.id.grid_description);
final ImageView imageView = (ImageView)grid.findViewById(R.id.grid_image);
textView.setText(web.get(position).getProductName());
textDescr.setText(String.valueOf(web.get(position).getProductPrice()) + "руб.");
// imageView.setImageResource(Imageid[position]);
imageView.setImageBitmap(Imageid.get(position));
} else {
grid = (View) convertView;
}
return grid;
}
}
但我有错误：
10-30 09:27:23.081 2820-2820/com.example.kinofood E/AndroidRuntime﹕ FATAL EXCEPTION: main
android.os.NetworkOnMainThreadException
at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)
at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
at java.net.InetAddress.getAllByName(InetAddress.java:214)
at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
at com.example.kinofood.MenuActivity.downloadBitmap(MenuActivity.java:162)
at com.example.kinofood.MenuActivity.setAdapter(MenuActivity.java:79)
at com.example.kinofood.MenuActivity.access$400(MenuActivity.java:38)
at com.example.kinofood.MenuActivity$RequestTask.onPostExecute(MenuActivity.java:232)
at com.example.kinofood.MenuActivity$RequestTask.onPostExecute(MenuActivity.java:186)
at android.os.AsyncTask.finish(AsyncTask.java:631)
at android.os.AsyncTask.access$600(AsyncTask.java:177)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5041)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
at dalvik.system.NativeStart.main(Native Method)
如何更改我的代码？谢谢
答案 0 :(得分：1)
您无法在MainThread上下载。如果你想这样做，你将不得不异步加载它，即使用AsyncTask。
但是将在线图像加载到ImageViews的最佳方法是使用第三方库。
我知道的图书馆：
通用图片加载器 - https://github.com/nostra13/Android-Universal-Image-Loader
毕加索 - http://square.github.io/picasso/
除了简单地加载图像，它们还可以处理你的缓存，动画，事件处理等。