Android AlertDialog

点击按钮，弹出对话框，点击确定关闭当前画面（Activity)
布局文件 dialog_demo.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android=""
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    <Button android:id="@+id/openDialogBtn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="onClick"
        android:text="打开Dialog"></Button>

</LinearLayout>

AlertActivity 类文件：

package com.example.twiter;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.AlertDialog.Builder;
import android.app.Dialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

public class AlertActivity extends Activity {

    private static final int DIALOG_ALERT = 10;

    public void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.dialog_demo);
    }

    public void onClick(View view){
        showDialog(DIALOG_ALERT);
    }

    @Override
    protected Dialog onCreateDialog(int id) {
        switch(id){
        case DIALOG_ALERT:
            Builder builder = new AlertDialog.Builder(this);
            builder.setMessage("干掉Activity");
            builder.setCancelable(true);
            builder.setPositiveButton("YES", new OkOnClickListener() );
            builder.setNegativeButton("Cancel", new CancelOnClickListener() );
            AlertDialog dialog = builder.create();
            dialog.show();
            break;
        }
        return super.onCreateDialog(id);
    }

    private final class OkOnClickListener implements DialogInterface.OnClickListener{

        @Override
        public void onClick(DialogInterface dialog, int which) {
            AlertActivity.this.finish();//干掉Activity
        }

    }

    private final class CancelOnClickListener implements DialogInterface.OnClickListener{

        @Override
        public void onClick(DialogInterface dialog, int which) {
            Toast.makeText(getApplicationContext(), "Activity will continue..", Toast.LENGTH_SHORT).show();
        }

    }
}

AndroidManifest.xml中添加以下行：

<activity android:name="com.example.twiter.AlertActivity">
              <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
         </activity>

效果：

<activity android:name="com.example.twiter.AlertActivity">
              <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
         </activity>