android - 进度对话框和后台线程处于 Activity 状态时处理屏幕方向更改？

Question

我的应用程序在后台线程中执行一些网络 Activity 或从 Web 服务获取数据。在开始之前，它会弹出一个进度对话框。对话框在处理程序上被关闭。这一切都很好，除非在对话框启动时屏幕方向发生变化此时我的应用程序崩溃了。我在 res/layout 文件夹中使用两种布局，一种纵向，一种在 res/中布局土地。当我将屏幕方向从纵向更改为横向或反之亦然时，我的应用程序会崩溃。

我知道为什么会这样。

当我切换方向时，Android 将创建一个新 View 。我可能会崩溃，因为\后台线程正在尝试更改旧线程的状态。 (它也可能有问题，因为后台线程不在 UI 线程上)。所以任何 friend 都可以告诉我如何解决这个问题，以便我可以继续。

当进度对话框和后台线程处于 Activity 状态时，如何处理屏幕方向变化？

提前致谢。

我的代码在这里

public class LoginActivity extends Activity {

EditText edUserName, edPassword;
Button btnLogin;
TextView txt_Alert;
ProgressDialog dialog;
String url, Status, result;
ConnectToWebService cn;

final Handler handler = new Handler() {

    @Override
    public void handleMessage(Message msg) {

        super.handleMessage(msg);

        dialog.dismiss();
        if (check_Status()) {
            login();
        }

    }

};

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    setTitle("Login");
    edUserName = (EditText) findViewById(R.id.edName);
    edPassword = (EditText) findViewById(R.id.edPass);
    btnLogin = (Button) findViewById(R.id.btnLogin);
    txt_Alert = (TextView) findViewById(R.id.txt_Required);



    btnLogin.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {

            String uName = edUserName.getText().toString().trim();
            String Pass = edPassword.getText().toString();

            cn = new ConnectToWebService();
            processThread();

}


protected void processThread() {
    dialog = ProgressDialog.show(LoginActivity.this, "",
            "Singing in ...", false);

    new Thread() {

        public void run() {


            Status = cn.callWebService(url);
            handler.sendEmptyMessage(0);

        }

    }.start();

}

我的日志猫

03-23 00:03:48.865: E/AndroidRuntime(11799): java.lang.IllegalArgumentException: View not attached to window manager
03-23 00:03:48.865: E/AndroidRuntime(11799):    at android.view.WindowManagerImpl.findViewLocked(WindowManagerImpl.java:355)
03-23 00:03:48.865: E/AndroidRuntime(11799):    at android.view.WindowManagerImpl.removeView(WindowManagerImpl.java:200)
03-23 00:03:48.865: E/AndroidRuntime(11799):    at android.view.Window$LocalWindowManager.removeView(Window.java:432)
03-23 00:03:48.865: E/AndroidRuntime(11799):    at android.app.Dialog.dismissDialog(Dialog.java:278)
03-23 00:03:48.865: E/AndroidRuntime(11799):    at android.app.Dialog.access$000(Dialog.java:71)
03-23 00:03:48.865: E/AndroidRuntime(11799):    at android.app.Dialog$1.run(Dialog.java:111)
03-23 00:03:48.865: E/AndroidRuntime(11799):    at android.app.Dialog.dismiss(Dialog.java:268)
03-23 00:03:48.865: E/AndroidRuntime(11799):    at com.palewar.coinop.LoginActivity$1.handleMessage(LoginActivity.java:42)
03-23 00:03:48.865: E/AndroidRuntime(11799):    at android.os.Handler.dispatchMessage(Handler.java:99)
03-23 00:03:48.865: E/AndroidRuntime(11799):    at android.os.Looper.loop(Looper.java:130)
03-23 00:03:48.865: E/AndroidRuntime(11799):    at android.app.ActivityThread.main(ActivityThread.java:3683)
03-23 00:03:48.865: E/AndroidRuntime(11799):    at java.lang.reflect.Method.invokeNative(Native Method)
03-23 00:03:48.865: E/AndroidRuntime(11799):    at java.lang.reflect.Method.invoke(Method.java:507)
03-23 00:03:48.865: E/AndroidRuntime(11799):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:861)
03-23 00:03:48.865: E/AndroidRuntime(11799):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:619)
03-23 00:03:48.865: E/AndroidRuntime(11799):    at dalvik.system.NativeStart.main(Native Method)

Answer 1

我找到了我的问题的解决方案并这样做了

package com.palewar;
import android.app.Activity;
import android.app.ProgressDialog;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;

public class ThreadActivity extends Activity {


    static ProgressDialog dialog;
    private Thread downloadThread;
    final static Handler handler = new Handler() {

        @Override
        public void handleMessage(Message msg) {

            super.handleMessage(msg);

            dialog.dismiss();

        }

    };

    protected void onDestroy() {
        if (dialog != null && dialog.isShowing()) {
            dialog.dismiss();
            dialog = null;
        }
        super.onDestroy();
    }

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        downloadThread = (Thread) getLastNonConfigurationInstance();
        if (downloadThread != null && downloadThread.isAlive()) {
            dialog = ProgressDialog.show(ThreadActivity.this, "",
                    "Signing in...", false);
        }

        dialog = ProgressDialog.show(ThreadActivity.this, "",
                "Signing in ...", false);

        downloadThread = new MyThread();
        downloadThread.start();
        // processThread();
    }

    // Save the thread
    @Override
    public Object onRetainNonConfigurationInstance() {
        return downloadThread;
    }


    static public class MyThread extends Thread {
        @Override
        public void run() {

            try {
                // Simulate a slow network
                try {
                    new Thread().sleep(5000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                handler.sendEmptyMessage(0);

            } finally {

            }
        }
    }

}

让我知道它对你有用，我们不是