android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views [duplicate]

问题

I'm having an issue which causes my application to force close and I'm not sure why this might be happening. My logcat and source are attached below. Please let me know if any additional information is required.

LOGCAT:

09-16 17:28:22.881: I/dalvikvm(18145): Total arena pages for JIT: 11
09-16 17:28:22.991: I/dalvikvm(18145): Total arena pages for JIT: 12
09-16 17:28:23.461: I/dalvikvm(18145): Total arena pages for JIT: 13
09-16 17:28:23.461: I/dalvikvm(18145): Total arena pages for JIT: 14
09-16 17:28:23.521: I/System.out(18145): Arrest No.
09-16 17:28:23.521: W/dalvikvm(18145): threadid=11: thread exiting with uncaught exception (group=0x41785300)
09-16 17:28:23.531: E/AndroidRuntime(18145): FATAL EXCEPTION: AsyncTask #1
09-16 17:28:23.531: E/AndroidRuntime(18145): java.lang.RuntimeException: An error occured while executing doInBackground()
09-16 17:28:23.531: E/AndroidRuntime(18145):    at android.os.AsyncTask$3.done(AsyncTask.java:299)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at java.util.concurrent.FutureTask.run(FutureTask.java:137)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at java.lang.Thread.run(Thread.java:856)
09-16 17:28:23.531: E/AndroidRuntime(18145): Caused by: android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
09-16 17:28:23.531: E/AndroidRuntime(18145):    at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:4609)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at android.view.ViewRootImpl.requestLayout(ViewRootImpl.java:835)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at android.view.View.requestLayout(View.java:15129)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at android.view.View.requestLayout(View.java:15129)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at android.view.View.requestLayout(View.java:15129)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at android.view.View.requestLayout(View.java:15129)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at android.view.View.requestLayout(View.java:15129)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at android.widget.TextView.checkForRelayout(TextView.java:6309)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at android.widget.TextView.setText(TextView.java:3547)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at android.widget.TextView.setText(TextView.java:3405)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at android.widget.TextView.setText(TextView.java:3380)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at com.example.test.MainActivity$MyTask.doInBackground(MainActivity.java:59)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at com.example.test.MainActivity$MyTask.doInBackground(MainActivity.java:1)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at android.os.AsyncTask$2.call(AsyncTask.java:287)
09-16 17:28:23.531: E/AndroidRuntime(18145):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
09-16 17:28:23.531: E/AndroidRuntime(18145):    ... 5 more

SOURCE:

public class MainActivity extends Activity {

TextView tv;
final String URL="http://example.com";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

tv = (TextView) findViewById(R.id.TextView01);
new MyTask().execute(URL);
}

private class MyTask extends AsyncTask<String, Void, String> {
ProgressDialog prog;
String title = "";
@Override
protected void onPreExecute() {
      prog = new ProgressDialog(MainActivity.this);
      prog.setMessage("Loading....");
      prog.show();
}
@Override
protected String doInBackground(String... params) {
    try {
        Document doc = Jsoup.connect(params[0]).get();
        Element tableHeader = doc.select("tr").first();


        for( Element element : tableHeader.children() )
        {
            // Here you can do something with each element
            System.out.println(element.text());
            tv.setText(element.text());
        }

        title = doc.title();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return title;
}
@Override
protected void onPostExecute(String result) {
    super.onPostExecute(result);
    prog.dismiss();
    tv.setText(result);
}
}
}

回答1:

You can't use tv.setText(element.text()); inside doInBackground. In a more general words, you can't update UI elements inside doInBackground method. Try exploring the method called onProgressUpdate.

I hope this helps.

来源：https://stackoverflow.com/questions/18837665/android-view-viewrootimplcalledfromwrongthreadexception-only-the-original-thre

标签

java

android-asynctask

forceclose