相关疑难解决方法(0)

我正在尝试编写一个更新的简单应用程序.为此,我需要一个简单的功能,可以下载一个文件,并显示当前进度的ProgressDialog.我知道怎么做ProgressDialog,但我不知道如何显示当前进度以及如何首先下载文件.

我有一个活动,并且我有一个班级.

text=new Dynamictext(...);
text.setText("txt");

在我的DynamicText java中,我有这样的代码:

public void setText(String text) {
    this.text=text;
    new asyncCreateText().execute();
    //this.createText(text);
}

//private Handler handler = new Handler();

private class asyncCreateText extends AsyncTask<Void, Void, Void> 
{
    @Override
    protected Void doInBackground(Void... unused) {
        return null;
    }

    @Override
    protected void onPostExecute(Void unused) {

    }
}

我明白了:

ERROR/AndroidRuntime(5176):引起:java.lang.RuntimeException:无法在未调用Looper.prepare()的线程内创建处理程序

我该如何处理这个错误？

ERROR/AndroidRuntime(5370): java.lang.ExceptionInInitializerError
ERROR/AndroidRuntime(5370):     at com.l.start.DynamicText.setText(DynamicText.java:125)
ERROR/AndroidRuntime(5370):     at com.l.start.OpenGLRenderer.initfonts(OpenGLRenderer.java:168)
ERROR/AndroidRuntime(5370):     at com.l.start.OpenGLRenderer.init(OpenGLRenderer.java:119)
ERROR/AndroidRuntime(5370):     at com.l.start.OpenGLRenderer.onSurfaceChanged(OpenGLRenderer.java:90)
ERROR/AndroidRuntime(5370):     at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1120)
ERROR/AndroidRuntime(5370):     at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:975)

ERROR/AndroidRuntime(5370): Caused by: java.lang.RuntimeException: 
    Can't create handler inside thread that …

当单击一个按钮时,我使用简单的线程来执行httpGet到服务器,但是我在执行后得到了这个.

Button b_back = (Button) findViewById(R.id.bback);
b_back.setOnClickListener(this);
Button b_sign_up = (Button) findViewById(R.id.signup_button);
b_sign_up.setOnClickListener(this);

@Override
public void onClick(View arg0) 
{
    // TODO Auto-generated method stub
    switch (arg0.getId()) 
    {
        case R.id.bback:
            Intent i = new Intent(this, MainSwitch.class);
            finish();
            startActivity(i);
            break;

            // More buttons go here (if any) ...

        case R.id.signup_button:
            if(username.getText().toString().equalsIgnoreCase("") ||
               password.getText().toString().equalsIgnoreCase("") ||
               email.getText().toString().equalsIgnoreCase(""))
            {
                AlertDialog.Builder dialog = new AlertDialog.Builder(this);
                dialog.setMessage("Please fill in all the gaps!");
                dialog.show();
            }
            else
            {
                //****** Call method that sends the information to server.
                Thread background …