Android 判斷APP當前的前臺後臺狀態

public int mCount = 0;
public static boolean isQiantai;
	public void regain() {
		registerActivityLifecycleCallbacks(new ActivityLifecycleCallbacks() {
			@Override
			public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
				
			}
			
			@Override
			public void onActivityStarted(Activity activity1) {
				mCount++;
				//如果mCount==1，說明是從後臺到前臺
				if (mCount == 1) {
					//執行app跳轉到前臺的邏輯
					isQiantai = true;
					Log.i("xda_qianhou","後臺到前臺----當前是前臺");
				}
			}
			
			@Override
			public void onActivityResumed(Activity activity) {
				
			}
			
			@Override
			public void onActivityPaused(Activity activity) {
				
			}
			
			@Override
			public void onActivityStopped(Activity activity) {
				mCount--;
				//如果mCount==0，說明是前臺到後臺
				if (mCount == 0) {
					//執行應用切換到後臺的邏輯
					isQiantai = false;
					Log.i("xda_qianhou","前臺到後臺----當前是後臺");
				}
			}
			
			@Override
			public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
				
			}
			
			@Override
			public void onActivityDestroyed(Activity activity) {
				
			}
		});
	}

在application的oncreate方法中調用該方法

	
	@Override
	public void onCreate(){
		super.onCreate();	
		regain();
		//...
	}

然後在需要的地方獲取這個布爾值isQiantai來判斷當前應用是否在前臺，完成對應的操作。

if(App.isQiantai){
		//執行APP在前臺的操作
		}else{
        //執行APP在後臺的操作
}