【发布时间】：2012-09-27 14:16:01
【问题描述】：
我是 Android 开发的初学者，我正在使用我的第一个应用程序，但遇到了问题。 我必须下载一些图片扔到互联网上，并在活动中展示它们。 在下载图像之前，我有一个 UI 延迟，所以我必须使用多线程。
我阅读了更多关于它的信息，我认为最简单的是使用 AsyncTask，但我收到了一个例外：Only the original thread that created a view hierarchy can touch its views.
我需要帮助。任何人都可以帮助我吗？代码是这样的：
public class Main extends Activity{
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Download download = new Download();
download.execute(null);
}
private class Download extends AsyncTask<String, Void, String>{
ImageButtonOverloaded[] imgView = new ImageButtonOverloaded[24];
TextView[] textView = new TextView[24];
@Override
protected String doInBackground(String... params) {
try{
URL url = null;
url = new URL(StaticClass.URL_HOST + "front_page_last_games_plaintext.php");
URLConnection conn = url.openConnection();
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String line;
initCovers();
int i = 0;
Log.d("SYNC", "i = 0");
while((line = reader.readLine()) != null){
String gameInfo[] = line.split("<NEXT>");
//Log.d("SYNC", gameInfo[0]);
//Log.d("SYNC", gameInfo[1]);
Drawable x = ImageOperations(Main.this, StaticClass.URL_HOST + "resize.php?imagine=" + gameInfo[0] ,"image.jpg");
Log.d("SYNC", "in while");
imgView[i].setImageDrawable(x);
Log.d("SYNC", "in while");
imgView[i].setGameID(gameInfo[0]);
imgView[i].setOnClickListener(new OnClickListener() {
public void onClick(View v) {
ImageButtonOverloaded temp = (ImageButtonOverloaded) v;
Intent intent = new Intent(Main.this, Single.class);
intent.putExtra("ID", temp.getGameID());
startActivity(intent);
}
});
textView[i].setText(gameInfo[1]);
textView[i].setGravity(Gravity.TOP);
textView[i].setGravity(Gravity.CENTER_HORIZONTAL);
textView[i].setTextColor(Color.WHITE);
i++;
}
}catch(Exception ex){
Log.d("SYNC", ex.getMessage());
}
return null;
}
private Drawable ImageOperations(Context ctx, String url, String saveFilename) {
try {
InputStream is = (InputStream) this.fetch(url);
Drawable d = Drawable.createFromStream(is, "src");
return d;
} catch (MalformedURLException e) {
e.printStackTrace();
return null;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
public Object fetch(String address) throws MalformedURLException,IOException {
URL url = new URL(address);
Object content = url.getContent();
return content;
}
private void initCovers(){
imgView[0] = (ImageButtonOverloaded) findViewById(R.id.imageButton1);
imgView[1] = (ImageButtonOverloaded) findViewById(R.id.imageButton2);
imgView[2] = (ImageButtonOverloaded) findViewById(R.id.imageButton3);
imgView[3] = (ImageButtonOverloaded) findViewById(R.id.imageButton4);
imgView[4] = (ImageButtonOverloaded) findViewById(R.id.imageButton5);
imgView[5] = (ImageButtonOverloaded) findViewById(R.id.imageButton6);
imgView[6] = (ImageButtonOverloaded) findViewById(R.id.imageButton7);
imgView[7] = (ImageButtonOverloaded) findViewById(R.id.imageButton8);
imgView[8] = (ImageButtonOverloaded) findViewById(R.id.imageButton9);
imgView[9] = (ImageButtonOverloaded) findViewById(R.id.imageButton10);
imgView[10] = (ImageButtonOverloaded) findViewById(R.id.imageButton11);
imgView[11] = (ImageButtonOverloaded) findViewById(R.id.imageButton12);
imgView[12] = (ImageButtonOverloaded) findViewById(R.id.imageButton13);
imgView[13] = (ImageButtonOverloaded) findViewById(R.id.imageButton14);
imgView[14] = (ImageButtonOverloaded) findViewById(R.id.imageButton15);
imgView[15] = (ImageButtonOverloaded) findViewById(R.id.imageButton16);
imgView[16] = (ImageButtonOverloaded) findViewById(R.id.imageButton17);
imgView[17] = (ImageButtonOverloaded) findViewById(R.id.imageButton18);
imgView[18] = (ImageButtonOverloaded) findViewById(R.id.imageButton19);
imgView[19] = (ImageButtonOverloaded) findViewById(R.id.imageButton20);
imgView[20] = (ImageButtonOverloaded) findViewById(R.id.imageButton21);
imgView[21] = (ImageButtonOverloaded) findViewById(R.id.imageButton22);
imgView[22] = (ImageButtonOverloaded) findViewById(R.id.imageButton23);
imgView[23] = (ImageButtonOverloaded) findViewById(R.id.imageButton24);
textView[0] = (TextView) findViewById(R.id.textView1);
textView[1] = (TextView) findViewById(R.id.textView2);
textView[2] = (TextView) findViewById(R.id.textView3);
textView[3] = (TextView) findViewById(R.id.textView4);
textView[4] = (TextView) findViewById(R.id.textView5);
textView[5] = (TextView) findViewById(R.id.textView6);
textView[6] = (TextView) findViewById(R.id.textView7);
textView[7] = (TextView) findViewById(R.id.textView8);
textView[8] = (TextView) findViewById(R.id.textView9);
textView[9] = (TextView) findViewById(R.id.textView10);
textView[10] = (TextView) findViewById(R.id.textView11);
textView[11] = (TextView) findViewById(R.id.textView12);
textView[12] = (TextView) findViewById(R.id.textView13);
textView[13] = (TextView) findViewById(R.id.textView14);
textView[14] = (TextView) findViewById(R.id.textView15);
textView[15] = (TextView) findViewById(R.id.textView16);
textView[16] = (TextView) findViewById(R.id.textView17);
textView[17] = (TextView) findViewById(R.id.textView18);
textView[18] = (TextView) findViewById(R.id.textView19);
textView[19] = (TextView) findViewById(R.id.textView20);
textView[20] = (TextView) findViewById(R.id.textView21);
textView[21] = (TextView) findViewById(R.id.textView22);
textView[22] = (TextView) findViewById(R.id.textView23);
textView[23] = (TextView) findViewById(R.id.textView24);
}
}}
【问题讨论】：
标签： android exception android-asynctask