Android应用开发学习笔记之AlertDialog对话框

作者：刘昊昱 

博客：http://blog.csdn.net/liuhaoyutz

 

本文中我们通过一个例子来看AlertDialog对话框的实现，其运行效果如下：

主布局文件main.xml内容如下：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" >    <TextView         android:id="@+id/textView"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:textSize="20dp"        android:text="对话框应用示例：" />"        <Button        android:id="@+id/button1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="按钮对话框" />    <Button        android:id="@+id/button2"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="列表对话框" />    <Button        android:id="@+id/button3"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="单选列表对话框" />    <Button        android:id="@+id/button4"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="多选列表对话框" /></LinearLayout>

布局文件中只是简单的放置了4个按钮。

下面看主Activity文件，其内容如下：

package com.liuhaoyu;import android.app.Activity;import android.app.AlertDialog;import android.app.AlertDialog.Builder;import android.content.DialogInterface;import android.content.DialogInterface.OnClickListener;import android.content.DialogInterface.OnMultiChoiceClickListener;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.Toast;public class MainActivity extends Activity {private boolean[] checkedItems;    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                Button button1 = (Button) findViewById(R.id.button1);button1.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {AlertDialog alert = new AlertDialog.Builder(MainActivity.this).create();alert.setIcon(R.drawable.image01);alert.setTitle("按钮对话框：");alert.setMessage("带按钮的对话框！");alert.setButton(DialogInterface.BUTTON_NEGATIVE,"取消", new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {Toast.makeText(MainActivity.this, "您单击了取消按钮",Toast.LENGTH_SHORT).show();}});alert.setButton(DialogInterface.BUTTON_POSITIVE,"确定", new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {Toast.makeText(MainActivity.this, "您单击了确定按钮",Toast.LENGTH_SHORT).show();}});alert.setButton(DialogInterface.BUTTON_NEUTRAL,"中立",new OnClickListener(){@Overridepublic void onClick(DialogInterface dialog, int which) {Toast.makeText(MainActivity.this, "您单击了中立按钮",Toast.LENGTH_SHORT).show();}});alert.show();}});Button button2 = (Button) findViewById(R.id.button2);button2.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {final String[] items = new String[] { "苹果", "三星", "HTC", "联想", "小米" };Builder builder = new AlertDialog.Builder(MainActivity.this);builder.setIcon(R.drawable.image01);builder.setTitle("请选择手机品牌：");builder.setItems(items, new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {Toast.makeText(MainActivity.this,"您选择了" + items[which], Toast.LENGTH_SHORT).show();}});builder.create().show();}});Button button3 = (Button) findViewById(R.id.button3);button3.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {final String[] items = new String[] { "苹果", "三星", "HTC", "联想", "小米" };Builder builder = new AlertDialog.Builder(MainActivity.this);builder.setIcon(R.drawable.image01);builder.setTitle("请选择手机品牌：");builder.setSingleChoiceItems(items, 0, new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {Toast.makeText(MainActivity.this,"您选择了" + items[which], Toast.LENGTH_SHORT).show();}});builder.setPositiveButton("确定", null);builder.create().show();}});Button button4 = (Button) findViewById(R.id.button4);button4.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {checkedItems= new boolean[] { false, true, false,true, false };final String[] items = new String[] { "苹果", "三星", "HTC", "联想", "小米" };Builder builder = new AlertDialog.Builder(MainActivity.this);builder.setIcon(R.drawable.image01);builder.setTitle("请选择手机品牌：");builder.setMultiChoiceItems(items, checkedItems,new OnMultiChoiceClickListener() {@Overridepublic void onClick(DialogInterface dialog,int which, boolean isChecked) {checkedItems[which]=isChecked;}});builder.setPositiveButton("确定", new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {String result="";for(int i=0;i<checkedItems.length;i++){if(checkedItems[i]){result+=items[i]+"、";}}if(!"".equals(result)){result=result.substring(0, result.length()-1);Toast.makeText(MainActivity.this, "您选择了[ "+result+" ]", Toast.LENGTH_LONG).show();}}});builder.create().show();}});    }}

程序中为4个按钮设置了点击监听器，在监听器中创建了4种不同的对话框。