안드로이드 앱 중복실행 막는 방법 좀 알려주세요

Question

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="~~~~~~~~"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-permission android:name="android.permission.INTERNET"/>
    
    <uses-sdk
        android:minSdkVersion="18"
        android:targetSdkVersion="23" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".Intro_Activity"
            android:label="@string/app_name" 
            android:launchMode="singleInstance"
            android:excludeFromRecents="true"
            android:taskAffinity="" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
            <intent-filter>
                <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"/>
            </intent-filter>
            <meta-data android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
                android:resource="@xml/device_filter"/>
        </activity>
        <activity android:name="SelectInterface"></activity>
        <activity android:name="MainActivity"></activity>
        
        
        <meta-data
           android:name="com.google.android.gms.version"
           android:value="@integer/google_play_services_version" />
         
    </application>

</manifest>

 

구글 결과 앱 중복실행 방지 방법으로....

android:launchMode="singleInstance"
            android:excludeFromRecents="true"
            android:taskAffinity="" >

이걸 추가하라고 해서 넣었는데....

앱 실행시키고 홈키 눌렀다가 다시 앱 실행시키면...

중복실행이 됩니다...ㅠㅠ

 

중복실행 깔끔하게 막는 방법 좀 알려주세요~