Java Android应用程序在打开链接时崩溃

嗯，我不知道为什么，但每次我在登录活动中点击提交按钮时，我的应用程序都会崩溃。主要活动效果良好

我的登录活动：

我的主要活动：

我的因特网管理员：

错误：

11-07 21:34:29.474:E/Trace1223:打开跟踪文件时出错：无此错误 文件或目录2 11-07 21:34:32.785:D/gralloc_goldfish1223: 检测到没有GPU仿真的仿真器。11-07 21:34:34.074: D/dalvikvm1223:GC_并发释放260K，10%释放7393K/8135K， 暂停16毫秒+15毫秒，总计59毫秒11-07 21:34:39.964： I/编舞1223：跳过248帧！申请可能是 在它的主线程上做了太多的工作。11-07 21:34:40.504: W/dalvikvm1223:threadid=12:线程退出，但出现未捕获异常 组=0x40a13300 11-07 21:34:40.564:E/AndroidRuntime1223:致命 异常：AsyncTask 2 11-07 21:34:40.564:E/AndroidRuntime1223: java.lang.RuntimeException:执行时出错 doInBackground 11-07 21:34:40.564:E/AndroidRuntime1223:at android.os.AsyncTask$3.doneAsyncTask.java:299 11-07 21:34:40.564: E/AndroidRuntime1223:at java.util.concurrent.FutureTask$Sync.innerSetExceptionFutureTask.java:273 11-07 21:34:40.564:E/AndroidRuntime1223:at java.util.concurrent.FutureTask.setExceptionFutureTask.java:124 11-07 21:34:40.564:E/AndroidRuntime1223:at java.util.concurrent.FutureTask$Sync.innerRunFutureTask.java:307 11-07 21:34:40.564:E/AndroidRuntime1223:at java.util.concurrent.FutureTask.runFutureTask.java:137 11-07 21:34:40.564:E/AndroidRuntime1223:at android.os.AsyncTask$SerialExecutor$1.runAsyncTask.java:230 11-07 21:34:40.564:E/AndroidRuntime1223:at java.util.concurrent.ThreadPoolExecutor.runWorkerThreadPoolExecutor.java:1076 11-07 21:34:40.564:E/AndroidRuntime1223:at java.util.concurrent.ThreadPoolExecutor$Worker.runThreadPoolExecutor.java:569 11-07 21:34:40.564:E/AndroidRuntime1223:at java:85611-0721:34:40.564: E/AndroidRuntime1223：由以下原因引起： android.view.ViewRootImpl$CalledFromErrorThreadException:只有 创建视图层次结构的原始线程可以接触其视图。 11-07 21:34:40.564:E/AndroidRuntime1223:at android.view.ViewRootImpl.checkThreadViewRootImpl.java:4609 11-07 21:34:40.564:E/AndroidRuntime1223:at android.view.ViewRootImpl.requestLayoutViewRootImpl.java:835 11-07 21:34:40.564:E/AndroidRuntime1223:at android.view.view.requestLayoutView.java:1512911-0721:34:40.564: E/AndroidRuntime1223:at android.view.view.requestLayoutView.java:1512911-0721:34:40.564: E/AndroidRuntime1223:at android.view.view.requestLayoutView.java:1512911-0721:34:40.564: E/AndroidRuntime1223:at android.view.view.requestLayoutView.java:1512911-0721:34:40.564: E/AndroidRuntime1223:at android.widget.RelativeLayout.requestLayoutRelativeLayout.java:292 11-07 21:34:40.564:E/AndroidRuntime1223:at android.view.view.requestLayoutView.java:1512911-0721:34:40.564: E/AndroidRuntime1223:at android.widget.TextView.checkForRelayoutTextView.java:6309 11-07 21:34:40.564:E/AndroidRuntime1223:at android.widget.TextView.setTextTextView.java:3547 11-07 21:34:40.564:E/AndroidRuntime1223:at android.widget.TextView.setTextTextView.java:340511-07 21:34:40.564:E/AndroidRuntime1223:at android.widget.TextView.setTextTextView.java:3380 11-07 21:34:40.564:E/AndroidRuntime1223:at de.blender4me.einkaufslite.LoginActivity$LongOperation.doInBackgroundLoginActivity.java:71 11-07 21:34:40.564:E/AndroidRuntime1223:at de.blender4me.einkaufslite.LoginActivity$LongOperation.doInBackgroundLoginActivity.java:1 11-07 21:34:40.564:E/AndroidRuntime1223:at android.os.AsyncTask$2.callAsyncTask.java:287 11-07 21:34:40.564: E/AndroidRuntime1223:at java.util.concurrent.FutureTask$Sync.innerRunFutureTask.java:305 11-07 21:34:40.564:E/AndroidRuntime1223:。。。5更多11-07 21:34:42.315:I/Process1223:发送信号。PID:1223信号：9

---

实际上，您正在尝试从AsyncTask的doInBackground更新应用程序UI，这会导致此错误

所以把你的代码改成

@Override
protected String doInBackground(Void... params) {
    internetHandler ih = new internetHandler();
    values = ih.getList(usernameString,passwordString,"","");
    return values[0];    
}

@Override
protected void onPostExecute(String result) {
   if(!result.equalsIgnoreCase("error") && !result.equalsIgnoreCase("401") && !result.equalsIgnoreCase("404")){
        userPass.setText("Yep");
    }else{
        userPass.setText(result);
    }
}   

---

由于doInBackground在worker线程中运行，因此您无法从它访问android的主应用程序UI线程，因此您必须从运行在UI线程上的onPostExecute更新UI部分。

您无法访问doInBackground中的UI-这就是onPostExecute的用途。如果您单击了日志中的异常，它会将您带到userPass.setText…可能是重复的，我将在明天尝试，谢谢！

package de.blender4me.einkaufsliste;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;


public class MainActivity extends Activity {

//Widgets
Button addItem;
Button loginMenu;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //listView
        LongOperation lo = new LongOperation();
        lo.execute();

        //register Widgets
        addItem =(Button) findViewById(R.id.addItem);
        addItem.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                openDialog();
            }
        });

        loginMenu = (Button) findViewById(R.id.loginMenu);
        loginMenu.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent i = new Intent(getApplicationContext(), LoginActivity.class);
                startActivity(i);
            }
        });
    }

@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;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

//Alert
public void openDialog(){
    AlertDialog.Builder alert = new AlertDialog.Builder(this);

    alert.setTitle("Zur Einkaufsliste hinzufügen");
    alert.setMessage(" ");

    // Set an EditText view to get user input 
    final EditText input = new EditText(this);
    alert.setView(input);

    alert.setPositiveButton("Bestätigen", new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog, int whichButton) {
      String value = input.getText().toString();
      // Do something with value!
      }
    });

    alert.setNegativeButton("Abbrechen", new DialogInterface.OnClickListener() {
      public void onClick(DialogInterface dialog, int whichButton) {
        // Canceled.
      }
    });

    alert.show();
}

//listView erstellen
private class LongOperation extends AsyncTask<Void, Void, String> {

    private String[] values = null;

    @Override
    protected String doInBackground(Void... params) {
        internetHandler ih = new internetHandler();
        values = ih.getList("TestUser","TestPass","TestValue","");
        return null;
    }

    @Override
    protected void onPostExecute(String result) {
        //Liste konvertieren
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(MainActivity.this, 
            R.layout.listview_item, //Genutztes Layout
            values); //Genutzter Array

        //listView einstellen
        ListView list = (ListView) findViewById(R.id.listView);
        list.setAdapter(adapter);
    }

    @Override
    protected void onPreExecute() {}

    @Override
    protected void onProgressUpdate(Void... values) {}
  }
}

package de.blender4me.einkaufsliste;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.regex.Pattern;

public class internetHandler {

    //Einkaufsplaner-API aufrufen
        public static String[] getList(String name, String pass, String addValue, String removeValue){

            InputStream is = null;

            try
            {
              URL url = new URL("https://einkaufsplaner.blender4me.de/api.php?name="+name+"&pass="+pass+"&addValue="+addValue+"&removeValue="+removeValue);
              BufferedReader in = new BufferedReader(
              new InputStreamReader(url.openStream()));

              String Values = null;

              for(int i = 0; i < 4; ++i){
                  Values = in.readLine();
              }
              in.close();

              String[] List = Values.split( Pattern.quote( ";" ) );
              return List;

            }
            catch ( Exception e ) {
              e.printStackTrace();
            }
            finally {
              if ( is != null )
                try { is.close(); } catch ( IOException e ) { }
            }
            String[] error = {"error"};
            return error;
        }
}

@Override
protected String doInBackground(Void... params) {
    internetHandler ih = new internetHandler();
    values = ih.getList(usernameString,passwordString,"","");
    return values[0];    
}

@Override
protected void onPostExecute(String result) {
   if(!result.equalsIgnoreCase("error") && !result.equalsIgnoreCase("401") && !result.equalsIgnoreCase("404")){
        userPass.setText("Yep");
    }else{
        userPass.setText(result);
    }
}