Android入门第九篇之AlertDialog .

时隔一年，又要准备做Android的开发了，最近复习和整理一下Android的知识。这次要说的是AlertDialog，这种对话框会经常遇到。AlertDialog跟WIN32开发中的Dialog不一样，AlertDialog是非阻塞的，而阻塞的对话框用的是PopupWindow。

先贴出程序运行的截图：

main.xml的源码：

<?xmlversion="1.0"encoding="utf-8"?>
<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>

<Buttonandroid:id="@+id/Button01"android:layout_height="wrap_content"android:text="非Layout型对话框"android:layout_width="fill_parent"></Button>
<Buttonandroid:id="@+id/Button02"android:layout_height="wrap_content"android:text="Layout型对话框"android:layout_width="fill_parent"></Button><Viewandroid:id="@+id/View01"android:layout_width="wrap_content"android:layout_height="wrap_content"></View>

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >

<Button android:id="@+id/Button01" android:layout_height="wrap_content" android:text="非Layout型对话框" android:layout_width="fill_parent"></Button>
<Button android:id="@+id/Button02" android:layout_height="wrap_content" android:text="Layout型对话框" android:layout_width="fill_parent"></Button><View android:id="@+id/View01" android:layout_width="wrap_content" android:layout_height="wrap_content"></View>

</LinearLayout>

下图是非Layout型对话框，直接使用AlertDialog

下图是使用了Layout的对话框，可以自定义控件，实现更复杂的对话框

dialoglayout.xml的源码：

<?xmlversion="1.0"encoding="utf-8"?>

<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"android:layout_height="wrap_content"
android:orientation="vertical">
<EditTextandroid:layout_height="wrap_content"
android:layout_width="fill_parent"android:layout_marginLeft="20dip"
android:layout_marginRight="20dip"android:textAppearance="?android:attr/textAppearanceMedium"android:id="@+id/edtInput"/>
</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="wrap_content"
	android:orientation="vertical">
	<EditText android:layout_height="wrap_content"
		android:layout_width="fill_parent" android:layout_marginLeft="20dip"
		android:layout_marginRight="20dip" android:textAppearance="?android:attr/textAppearanceMedium" android:id="@+id/edtInput"/>
</LinearLayout>

程序源码：

packagecom.testAlertDialog;

importandroid.app.Activity;
importandroid.app.AlertDialog;
importandroid.content.Context;
importandroid.content.DialogInterface;
importandroid.os.Bundle;
importandroid.view.Gravity;
importandroid.view.LayoutInflater;
importandroid.view.View;
importandroid.view.View.OnClickListener;
importandroid.widget.Button;
importandroid.widget.EditText;
importandroid.widget.PopupWindow;


publicclasstestAlertDialogextendsActivity{
ButtonbtnShowDialog;
ButtonbtnShowDialog_Layout;
/**Calledwhentheactivityisfirstcreated.*/
@Override
publicvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//定义按钮
btnShowDialog=(Button)this.findViewById(R.id.Button01);
btnShowDialog.setOnClickListener(newClickEvent());
btnShowDialog_Layout=(Button)this.findViewById(R.id.Button02);
btnShowDialog_Layout.setOnClickListener(newClickEvent());
}


//统一处理按键事件
classClickEventimplementsOnClickListener{

@Override
publicvoidonClick(Viewv){
//TODOAuto-generatedmethodstub
if(v==btnShowDialog)
showDialog(testAlertDialog.this);

elseif(v==btnShowDialog_Layout)
showDialog_Layout(testAlertDialog.this);

}

}

//显示基本的AlertDialog
privatevoidshowDialog(Contextcontext){
AlertDialog.Builderbuilder=newAlertDialog.Builder(context);
builder.setIcon(R.drawable.icon);
builder.setTitle("Title");
builder.setMessage("Message");
builder.setPositiveButton("Button1",
newDialogInterface.OnClickListener(){
publicvoidonClick(DialogInterfacedialog,intwhichButton){
setTitle("点击了对话框上的Button1");
}
});
builder.setNeutralButton("Button2",
newDialogInterface.OnClickListener(){
publicvoidonClick(DialogInterfacedialog,intwhichButton){
setTitle("点击了对话框上的Button2");
}
});
builder.setNegativeButton("Button3",
newDialogInterface.OnClickListener(){
publicvoidonClick(DialogInterfacedialog,intwhichButton){
setTitle("点击了对话框上的Button3");
}
});
builder.show();
}


//显示基于Layout的AlertDialog
privatevoidshowDialog_Layout(Contextcontext){
LayoutInflaterinflater=LayoutInflater.from(this);
finalViewtextEntryView=inflater.inflate(
R.layout.dialoglayout,null);
finalEditTextedtInput=(EditText)textEntryView.findViewById(R.id.edtInput);
finalAlertDialog.Builderbuilder=newAlertDialog.Builder(context);
builder.setCancelable(false);
builder.setIcon(R.drawable.icon);
builder.setTitle("Title");
builder.setView(textEntryView);
builder.setPositiveButton("确认",
newDialogInterface.OnClickListener(){
publicvoidonClick(DialogInterfacedialog,intwhichButton){
setTitle(edtInput.getText());
}
});
builder.setNegativeButton("取消",
newDialogInterface.OnClickListener(){
publicvoidonClick(DialogInterfacedialog,intwhichButton){
setTitle("");
}
});
builder.show();
}
}