android动态修改app桌面icon

转：http://blog.csdn.net/cherry609195946/article/details/39553867

原理：
在Manifest文件中，使用<activity-alias>标签为我们的入口Activity准备多个，拥有<activity-alias>标签的activity是为了指向入口Activity，每个拥有<activity-alias>标签的activity都可以单独设置一个icon，在程序中我们动态设置<activity-alias>，然后kill掉launcher，等launcher重启后，icon就替换了

注意：
kill掉launcher需加权限 <uses-permission android:name="android.permission.KILL_BACKGROUND_PROCESSES"/>

代码：
Manifest.xml:

<activity
            android:name="com.dance.changeicondemo.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
            </intent-filter>
        </activity>
        <activity-alias
            android:name="com.example.changeicondemo.ActivityAlias1"
            android:enabled="true"
            android:icon="@drawable/ic_launcher"
            android:label="@string/app_name"
            android:targetActivity="com.dance.changeicondemo.MainActivity" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity-alias>
        <activity-alias
            android:name="com.example.changeicondemo.ActivityAlias2"
            android:enabled="false"
            android:icon="@drawable/icon2"
            android:label="@string/app_name"
            android:targetActivity="com.dance.changeicondemo.MainActivity" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity-alias>

code:

private void setIcon(String activity_alias) {
        Context ctx = MyApplication.getContext();
        PackageManager pm = ctx.getPackageManager();
        ActivityManager am = (ActivityManager) ctx.getSystemService(Activity.ACTIVITY_SERVICE);

        // Enable/disable activity-aliases
        pm.setComponentEnabledSetting(
                new ComponentName(ctx, ACTIVITY_ALIAS_1),
                ACTIVITY_ALIAS_1.equals(activity_alias) ? PackageManager.COMPONENT_ENABLED_STATE_ENABLED
                        : PackageManager.COMPONENT_ENABLED_STATE_DISABLED,
                PackageManager.DONT_KILL_APP);
        pm.setComponentEnabledSetting(
                new ComponentName(ctx, ACTIVITY_ALIAS_2),
                ACTIVITY_ALIAS_2.equals(activity_alias) ? PackageManager.COMPONENT_ENABLED_STATE_ENABLED
                        : PackageManager.COMPONENT_ENABLED_STATE_DISABLED,
                PackageManager.DONT_KILL_APP);

        // Find launcher and kill it
        Intent i = new Intent(Intent.ACTION_MAIN);
        i.addCategory(Intent.CATEGORY_HOME);
        i.addCategory(Intent.CATEGORY_DEFAULT);
        List<ResolveInfo> resolves = pm.queryIntentActivities(i, 0);
        for (ResolveInfo res : resolves) {
            if (res.activityInfo != null) {
                am.killBackgroundProcesses(res.activityInfo.packageName);
            }
        }
    }