Android如何使用样式创建半透明窗体

本示例介绍如何使用Android系统样式和自定义样式创建半透明界面。

1. 定义清单文件（AndroidManifest.xml）

<?xmlversion="1.0"encoding="utf-8"?>
 
<manifestxmlns:android="http://schemas.android.com/apk/res/android"
 
      package="my.andriod.test"
 
      android:versionCode="1"
 
      android:versionName="1.0">
 
    <applicationandroid:icon="@drawable/icon"android:label="@string/app_name">
 
        <!-- 使用自定义半透明主题样式  android:theme="@style/Theme.Translucent" -->
 
        <activityandroid:name=".TranslucentActivity"
 
                  android:label="@string/app_name"              
 
                  android:theme="@style/Theme.Translucent">
 
            <intent-filter>
 
                <actionandroid:name="android.intent.action.MAIN"/>
 
                <categoryandroid:name="android.intent.category.LAUNCHER"/>
 
            </intent-filter>
 
        </activity>
 
        <!-- 使用Android系统半透明主题样式
 
        <activity android:name=".TranslucentActivity"
 
                  android:label="@string/app_name"              
 
                  android:theme="@android:style/Theme.Translucent">
 
            <intent-filter>
 
                <action android:name="android.intent.action.MAIN" />
 
                <category android:name="android.intent.category.LAUNCHER" />
 
            </intent-filter>
 
        </activity>
 
         -->
 
    </application>
 
    <uses-sdkandroid:minSdkVersion="9"/>
 
</manifest>

2. 定义字符串资源（strings.xml）

<?xmlversion="1.0"encoding="utf-8"?>
 
<resources>
 
    <stringname="hello">Hello World, TranslucentActivity!</string>
 
    <stringname="app_name">TranslucentActivity</string>
 
    <stringname="activity_translucent">App/Activity/Translucent</string>
 
    <stringname="translucent_background">Example of how you can make an
 
            activity have a translucent background, compositingover
 
            whatever is behind it.</string>
 
</resources>

3. 定义自定义样式（values/styles.xml）

<?xmlversion="1.0"encoding="utf-8"?>
 
<resources>
 
    <!-- 继承Android系统的半透明主题样式，并指定半透明背景的颜色、隐藏窗口标题和前景色  -->
 
    <stylename="Theme.Translucent"parent="android:style/Theme.Translucent">
 
        <itemname="android:windowBackground">@drawable/translucent_background</item>
 
        <itemname="android:windowNoTitle">true</item>
 
        <itemname="android:colorForeground">#fff</item>
 
    </style>
 
</resources>

4. 定义半透明颜色（colors.xml）

<?xmlversion="1.0"encoding="utf-8"?>
 
<resources>
 
    <drawablename="translucent_background">#e0000000</drawable>
 
</resources>

5. 定义布局文件（translucent_background.xml）

<?xmlversion="1.0"encoding="utf-8"?>
 
<!-- 在Activity中显示文本-->
 
<TextViewxmlns:android="http://schemas.android.com/apk/res/android"android:id="@+id/text"
 
    android:layout_width="match_parent"android:layout_height="match_parent"
 
    android:gravity="center_vertical|center_horizontal"
 
    android:text="@string/translucent_background"/>

6. 创建Activity（TranslucentActivity.java）

packagemy.andriod.test;
 
  
 
importandroid.app.Activity;
 
importandroid.os.Bundle;
 
  
 
publicclassTranslucentActivity extendsActivity {
 
    /** Activity首次创建时，调用这个方法*/
 
    @Override
 
    publicvoidonCreate(Bundle savedInstanceState) {
 
        super.onCreate(savedInstanceState);
 
        //填充布局
 
        setContentView(R.layout.translucent_background);
 
    }
 
}