Android Activity定制需要的Title

Activity界面默认的Title是只有文字描述的，当我们想要做成类似微信中Tilte行带有导航和多功能效果的时候，我们就需要自己去定义需要的布局来加载它。上次我们讲到了Activity的全屏显示和去掉Title，说白了就是改变Window窗口features

/** Flag for the "options panel" feature.  This is enabled by default. */
public static final int FEATURE_OPTIONS_PANEL = 0;
/** Flag for the "no title" feature, turning off the title at the top
*  of the screen. */
public static final int FEATURE_NO_TITLE = 1;
/** Flag for the progress indicator feature */
public static final int FEATURE_PROGRESS = 2;
/** Flag for having an icon on the left side of the title bar */
public static final int FEATURE_LEFT_ICON = 3;
/** Flag for having an icon on the right side of the title bar */
public static final int FEATURE_RIGHT_ICON = 4;
/** Flag for indeterminate progress */
public static final int FEATURE_INDETERMINATE_PROGRESS = 5;
/** Flag for the context menu.  This is enabled by default. */
public static final int FEATURE_CONTEXT_MENU = 6;
/** Flag for custom title. You cannot combine this feature with other title features. */
public static final int FEATURE_CUSTOM_TITLE = 7;
/**
* Flag for enabling the Action Bar.
* This is enabled by default for some devices. The Action Bar
* replaces the title bar and provides an alternate location
* for an on-screen menu button on some devices.
*/
public static final int FEATURE_ACTION_BAR = 8;
/**
* Flag for requesting an Action Bar that overlays window content.
* Normally an Action Bar will sit in the space above window content, but if this
* feature is requested along with {@link #FEATURE_ACTION_BAR} it will be layered over
* the window content itself. This is useful if you would like your app to have more control
* over how the Action Bar is displayed, such as letting application content scroll beneath
* an Action Bar with a transparent background or otherwise displaying a transparent/translucent
* Action Bar over application content.
*
* <p>This mode is especially useful with {@link View#SYSTEM_UI_FLAG_FULLSCREEN
* View.SYSTEM_UI_FLAG_FULLSCREEN}, which allows you to seamlessly hide the
* action bar in conjunction with other screen decorations.
*
* <p>As of {@link android.os.Build.VERSION_CODES#JELLY_BEAN}, when an
* ActionBar is in this mode it will adjust the insets provided to
* {@link View#fitSystemWindows(android.graphics.Rect) View.fitSystemWindows(Rect)}
* to include the content covered by the action bar, so you can do layout within
* that space.
*/
public static final int FEATURE_ACTION_BAR_OVERLAY = 9;
/**
* Flag for specifying the behavior of action modes when an Action Bar is not present.
* If overlay is enabled, the action mode UI will be allowed to cover existing window content.
*/
public static final int FEATURE_ACTION_MODE_OVERLAY = 10;

通过上面的源码我们可以看到，如果我要定制自己的Title，我们需要采用Window.FEATURE_CUSTOM_TITLE这个特征来实现。需要注意的是，Window.FEATURE_CUSTOM_TITLE这个特征不能其他特征一起使用，还有就是必须在setContentView()方法之前使用（这个是所有Window特征改变的必须条件），不然无效首先是布局文件

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

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:background="@drawable/ic_launcher" />

<TextView
android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:shadowColor="#000986"
android:shadowDx="1"
android:shadowDy="1"
android:shadowRadius="1"
android:textColor="@android:color/white"
android:textSize="20sp"
android:textStyle="bold" />

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:background="@drawable/ic_launcher" />

</RelativeLayout>

我只加入了2张图片，大家可以按照自己的需要来添加元素下面就上代码了

getWindow().requestFeature(Window.FEATURE_CUSTOM_TITLE);

setContentView(R.layout.main);

getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.custom_title);

这样就实现了自定义Title的效果，当时，当我们运行在android sdk 3.0以上的时候会出现报如下错误：android.util.AndroidRuntimeException: You cannot combine custom titles with other title features原因在于，3.0以上的系统默认使用了Window.FEATURE_ACTION_BAR，我们需要使用自己的样式来修改它首先考虑到不同版本，建立vlaues-v11和values-v14两个文件夹满足，3.0以上和4.0以上看样式style.xml改变背景色修改android:windowTitleBackgroundStyle的值，改变标题栏高度则修改 android:windowTitleSize的值去掉windowActionBar特征

<resources>

<!--
Base application theme for API 14+. This theme completely replaces
AppBaseTheme from BOTH res/values/styles.xml and
res/values-v11/styles.xml on API 14+ devices.
-->
<style name="AppBaseTheme" parent="android:Theme.Holo.Light.DarkActionBar">
<!-- API 14 theme customizations can go here. -->
<item name="android:windowActionBar">false</item>
<item name="android:windowTitleSize">50dip</item>
<item name="android:windowTitleBackgroundStyle">@style/CustomWindowTitleBackground</item>
</style>

<style name="CustomWindowTitleBackground">
<item name="android:background">@drawable/stripes</item>
</style>

</resources>

接着再修改AndroidManifest.xml文件，找到要自定义标题栏的Activity，添加上android:theme值，

<activity android:name=".MainActivity" android:theme="@style/activityTitlebar">

这样就解决了问题