android会话框alert使用例子分享
点击页面的退出按钮弹出alert对话框，对话框中有确定，关闭和取消三个事件。
解决方法：
1、activity_main.xml代码：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.ff.MainActivity" >
<Button
android:id="@+id/btnShowAlert"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="26dp"
android:text="退出" />
</RelativeLayout>
2、后端代码MainActivity.java：
package com.example.ff;
import java.util.Calendar;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.TimePicker;
import android.widget.Toast;
public class MainActivity extends Activity {
Button btnShow;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnShow = (Button) findViewById(R.id.btnShowAlert);
btnShow.setOnClickListener(listener);
}
View.OnClickListener listener = new View.OnClickListener() {
@Override
public void onClick(View arg0) {
AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
builder.setTitle("显示");
builder.setMessage("真的要退出吗？");
//设置点返回按钮是否可以取消对话框，默认是true
builder.setCancelable(true);
builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface arg0, int arg1) {
//结束当前的Activity
finish();
}
});
builder.setNeutralButton("关闭", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface arg0, int arg1) {
Toast.makeText(MainActivity.this, "你选中了关闭按钮",
Toast.LENGTH_LONG).show();
}
});
builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface arg0, int arg1) {
Toast.makeText(MainActivity.this, "你选中了取消按钮",
Toast.LENGTH_LONG).show();
}
});
builder.show();
}
};
}