小编ble*_*ded的帖子

我尝试了类似堆栈溢出的以下内容Clean,Build Project Restart Eclipse

我也试过更新所有内容:从SDK和Eclipse插件重启模拟器等

Log Cat输出:

09-26 22:11:49.182: E/AndroidRuntime(1393): FATAL EXCEPTION: main
09-26 22:11:49.182: E/AndroidRuntime(1393): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.ass2/com.example.ass2.MP3Player}: java.lang.ClassCastException: android.widget.ImageButton cannot be cast to android.widget.Button
09-26 22:11:49.182: E/AndroidRuntime(1393):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
09-26 22:11:49.182: E/AndroidRuntime(1393):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
09-26 22:11:49.182: E/AndroidRuntime(1393):     at android.app.ActivityThread.access$600(ActivityThread.java:141)
09-26 22:11:49.182: E/AndroidRuntime(1393):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
09-26 22:11:49.182: E/AndroidRuntime(1393):     at android.os.Handler.dispatchMessage(Handler.java:99)
09-26 22:11:49.182: E/AndroidRuntime(1393):     at android.os.Looper.loop(Looper.java:137)
09-26 22:11:49.182: E/AndroidRuntime(1393):     at android.app.ActivityThread.main(ActivityThread.java:5041)
09-26 22:11:49.182: E/AndroidRuntime(1393):     at java.lang.reflect.Method.invokeNative(Native Method)
09-26 22:11:49.182: E/AndroidRuntime(1393):     at java.lang.reflect.Method.invoke(Method.java:511)
09-26 22:11:49.182: E/AndroidRuntime(1393):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) …

我是android的初学者,对于一个uny课程的项目,我们必须开发5个简单的应用程序,然后将它们"合并"在一起.所以你从一个Activity/ListView启动每个应用程序.所有应用程序都单独运行,但是当从列表视图运行一个应用程序时,我得到以下 *AsyncTask#1执行doinBackground()时发生错误; *

 @Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);


    reportarray= new ArrayList<String>();


    try {
        URL url = new URL("http://www.yr.no/sted/Sverige/Kronoberg/V%E4xj%F6/forecast.xml");
        AsyncTask task = new WeatherRetriever().execute(url);
    } catch (IOException ioe ) {
        ioe.printStackTrace();
    }
    adapter= new Adapter(this);
    setListAdapter(adapter);



}

这似乎是一个线程问题,这里是我使用的更多代码

private class WeatherRetriever extends AsyncTask<URL, Void, WeatherReport> {
    protected WeatherReport doInBackground(URL... urls) {
        try {
            return WeatherHandler.getWeatherReport(urls[0]);
        } catch (Exception e) {
            throw new RuntimeException(e);
        } 
    }

    protected void onProgressUpdate(Void... progress) {

    }

    protected void onPostExecute(WeatherReport result) {
        report …