使用样式文件，在values 目录下新建styles.xml文件，编写如下代码：
<
resources
>
< style name ="dialog" parent ="@android:style/Theme.Dialog" >
< item name ="android:windowFrame" > @null </ item >
< item name ="android:windowIsFloating" > true </ item >
< item name ="android:windowIsTranslucent" > false </ item >
< item name ="android:windowNoTitle" > true </ item >
< item name ="android:background" > @android:color/black </ item >
< item name ="android:windowBackground" > @null </ item >
< item name ="android:backgroundDimEnabled" > false </ item >
</ style >
</ resources >
< style name ="dialog" parent ="@android:style/Theme.Dialog" >
< item name ="android:windowFrame" > @null </ item >
< item name ="android:windowIsFloating" > true </ item >
< item name ="android:windowIsTranslucent" > false </ item >
< item name ="android:windowNoTitle" > true </ item >
< item name ="android:background" > @android:color/black </ item >
< item name ="android:windowBackground" > @null </ item >
< item name ="android:backgroundDimEnabled" > false </ item >
</ style >
</ resources >
调用时，使用AlerDialog的接口类，Dialog 接口编写如下代码：
Dialog dialog
=
new
Dialog(SetActivity.
this
, R.style.dialog);
dialog.setContentView(R.layout.test);
dialog.show();
dialog.setContentView(R.layout.test);
dialog.show();
下面我们查看一下Dialog的源码文件，里面的构造函数为如下：
public
Dialog(Context context,
int
theme) {
mContext = new ContextThemeWrapper(
context, theme == 0 ? com.android. internal .R.style.Theme_Dialog : theme);
mWindowManager = (WindowManager)context.getSystemService( " window " );
Window w = PolicyManager.makeNewWindow(mContext);
mWindow = w;
w.setCallback( this );
w.setWindowManager(mWindowManager, null , null );
w.setGravity(Gravity.CENTER);
mUiThread = Thread.currentThread();
mDismissCancelHandler = new DismissCancelHandler( this );
}
mContext = new ContextThemeWrapper(
context, theme == 0 ? com.android. internal .R.style.Theme_Dialog : theme);
mWindowManager = (WindowManager)context.getSystemService( " window " );
Window w = PolicyManager.makeNewWindow(mContext);
mWindow = w;
w.setCallback( this );
w.setWindowManager(mWindowManager, null , null );
w.setGravity(Gravity.CENTER);
mUiThread = Thread.currentThread();
mDismissCancelHandler = new DismissCancelHandler( this );
}
这里面我们可以看出，Android 使用了默认的构造函数为Dialog 设置样式，如果没有为其设置样式，即默认加载事先编写好的样式文件，Dialog 一共由多个9.png的图片构成，大部分都是带有边框的9.png图片，所以就是为什么我们上边的样式文件要将其背景去除掉。这个东西搞了我好久，希望对你有帮助
前后效果对比
未设置前：
设置后：
本文转自 terry_龙 51CTO博客，原文链接：http://blog.51cto.com/terryblog/388582，如需转载请自行联系原作者
