最近看到好幾個銀行類app，應(yīng)用切出去之后會提示“XXX進(jìn)入后臺運(yùn)行”

API 14之后，Application可以注冊ActivityLifecycleCallbacks這個接口

application.registerActivityLifecycleCallbacks(new Application.ActivityLifecycleCallbacks() {
            @Override
            public void onActivityCreated(Activity activity, Bundle bundle) {
            }

            @Override
            public void onActivityStarted(Activity activity) {
                //說明從后臺回到了前臺
                mFinalCount++;
            }

            @Override
            public void onActivityResumed(Activity activity) {
            }

            @Override
            public void onActivityPaused(Activity activity) {

            }

            @Override
            public void onActivityStopped(Activity activity) {
                mFinalCount--;
                //說明從前臺回到了后臺
                if (mFinalCount == 0 ) {
                    ToastTools.showShort(application.getApplicationContext(), "進(jìn)入后臺運(yùn)行");
                }
            }

            @Override
            public void onActivitySaveInstanceState(Activity activity, Bundle bundle) {

            }

            @Override
            public void onActivityDestroyed(Activity activity) {
            }
        });