How to change an application icon programmatically in Android

gistfile1.xml

//1 . Modify your MainActivity section in AndroidManifest.xml, delete from it, line with MAIN category in intent-//filter section

<activity android:name="ru.quickmessage.pa.MainActivity"
    android:configChanges="keyboardHidden|orientation"
    android:screenOrientation="portrait"
    android:label="@string/app_name"
    android:theme="@style/CustomTheme"
    android:launchMode="singleTask">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />//DELETE THIS LINE
    </intent-filter>
</activity>

<activity-alias android:label="@string/app_name" 
    android:icon="@drawable/icon" 
    android:name=".MainActivity-Red"
    android:enabled="false"
    android:targetActivity=".MainActivity">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>   
</activity-alias>

gistfile2.java

getPackageManager().setComponentEnabledSetting(
        new ComponentName("ru.quickmessage.pa", "ru.quickmessage.pa.MainActivity-Red"), 
            PackageManager.COMPONENT_ENABLED_STATE_ENABLED, PackageManager.DONT_KILL_APP);

//不显示icon的代码如下
getPackageManager().setComponentEnabledSetting(
        getComponentName(), PackageManager.COMPONENT_ENABLED_STATE_DISABLED, PackageManager.DONT_KILL_APP);

gistfile3.xml

//here is superuser.apk code

        <activity android:theme="@style/Theme.Sherlock.Light" android:label="@string/app_name" android:icon="@drawable/transparent" android:name=".MainActivity" android:exported="true" android:excludeFromRecents="true" android:launchMode="singleTask" android:configChanges="locale|keyboard|keyboardHidden|orientation|screenLayout" android:noHistory="false" android:hardwareAccelerated="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
            </intent-filter>
        </activity>
        <activity-alias android:label="@string/app_name" android:icon="@drawable/ic_launcher_emblem" android:name=".MainActivity-Emblem" android:enabled="true" android:targetActivity=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity-alias>
        <activity-alias android:label="@string/app_name" android:icon="@drawable/ic_launcher_superandy" android:name=".MainActivity-SuperAndy" android:enabled="false" android:targetActivity=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity-alias>
        <activity-alias android:label="@string/app_name" android:icon="@drawable/ic_launcher_original" android:name=".MainActivity-Original" android:enabled="false" android:targetActivity=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity-alias>
        <activity-alias android:label="@string/app_name" android:icon="@drawable/ic_launcher_chip" android:name=".MainActivity-Chip" android:enabled="false" android:targetActivity=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity-alias>
        <activity-alias android:label="@string/app_name" android:icon="@drawable/ic_launcher_supersu" android:name=".MainActivity-SuperSU" android:enabled="false" android:targetActivity=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity-alias>

When component has been disabled, the app widget on launcher will be deleted also.

I want to simply change application icon from main activity.tell me code which is required in activity and in manifest file.

I want to simply change application icon from main activity.tell me code which is required in activity and in manifest file.

is it possible to change app icon without closing the application , as in my app we need to change app icon after user launched his application , so can I change app icon with closing it , as closing kind of feels weird just after login.