Android的AlertDialog详解

AlertDialog的构造方法全部是Protected的，所以不能直接通过new一个AlertDialog来创建出一个AlertDialog。

要创建一个AlertDialog，就要用到AlertDialog.Builder中的create()方法。

使用AlertDialog.Builder创建对话框需要了解以下几个方法：

setTitle ：为对话框设置标题
setIcon ：为对话框设置图标
setMessage：为对话框设置内容
setView ： 给对话框设置自定义样式
setItems ：设置对话框要显示的一个list，一般用于显示几个命令时
setMultiChoiceItems ：用来设置对话框显示一系列的复选框
setNeutralButton ：普通按钮

setPositiveButton ：给对话框添加"Yes"按钮
setNegativeButton ：对话框添加"No"按钮
create ： 创建对话框
show ：显示对话框
一、简单的AlertDialog

下面，创建一个简单的ALertDialog并显示它：

[java] package com.tianjf;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.os.Bundle;

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

Dialog alertDialog = new AlertDialog.Builder(this).
setTitle("对话框的标题").
setMessage("对话框的内容").
setIcon(R.drawable.ic_launcher).
create();
alertDialog.show();
}
}
package com.tianjf;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.os.Bundle;

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

Dialog alertDialog = new AlertDialog.Builder(this).
setTitle("对话框的标题").
setMessage("对话框的内容").
setIcon(R.drawable.ic_launcher).
create();
alertDialog.show();
}
}运行结果如下：

http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center" >

<TextView
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="@string/user" />

<EditText
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="1" />
</LinearLayout>

<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center" >

<TextView
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="@string/passward" />

<EditText
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="1" />
</LinearLayout>

</LinearLayout>
<?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" >

<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center" >

<TextView
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="@string/user" />

<EditText
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="1" />
</LinearLayout>

<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center" >

<TextView
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="@string/passward" />

<EditText
android:layout_width="0dip"
android:layout_height="wrap_content"
android:layout_weight="1" />
</LinearLayout>

</LinearLayout>
然后在Activity里面把Login画面的布局文件添加到AlertDialog上

[java] package com.tianjf;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;

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

// 取得自定义View
LayoutInflater layoutInflater = LayoutInflater.from(this);
View myLoginView = layoutInflater.inflate(R.layout.login, null);

Dialog alertDialog = new AlertDialog.Builder(this).
setTitle("用户登录").
setIcon(R.drawable.ic_launcher).
setView(myLoginView).
setPositiveButton("登录", new DialogInterface.OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
}
}).
setNegativeButton("取消", new DialogInterface.OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
}
}).
create();
alertDialog.show();
}
}
package com.tianjf;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;

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

// 取得自定义View
LayoutInflater layoutInflater = LayoutInflater.from(this);
View myLoginView = layoutInflater.inflate(R.layout.login, null);

Dialog alertDialog = new AlertDialog.Builder(this).
setTitle("用户登录").
setIcon(R.drawable.ic_launcher).
setView(myLoginView).
setPositiveButton("登录", new DialogInterface.OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
}
}).
setNegativeButton("取消", new DialogInterface.OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
}
}).
create();
alertDialog.show();
}
}运行结果如下：

摘自 殇雲的专栏