判斷本應用是不是在前臺
首先由個比較通用的方法。
Activity切換的時候執行邏輯:
A.onCreate->A.onStart()->A.onResume()->A.onPause()->B.onCreate->B.onStart()->B.onResume()->B啟動完畢->A.onStop()
所以只要統計onStart和onStop的次數就好了。
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由於我的專案裡有特殊原因:
引入了另外的工程,包名相同但是和我負責的部分完全獨立,也無法去改,於是使用了下面的方法
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最近有個需求,在應用中增加一個全域性的懸浮球,擬採用Toast方式實現,但Toast是系統級Alert。
應用後臺執行時也會顯示在桌面上,因此需要在每個Activity的生命週期中判斷當前應用還在不在棧頂(使用者可見、正在執行)。
先貼上實現程式碼吧,程式碼有專案依賴,如果有人需要的話拿去把依賴去掉就好了。
定義一個基類,所有Activity都需要繼承這個基類。重寫onResume( )實現顯示邏輯,重寫onStop( )顯示隱藏邏輯。
package com.ct108.open.Base; import android.app.Activity; import android.os.Bundle; import com.ct108.open.Utils.GetTopInfo; import com.ct108.open.Utils.fordebug.LogUtil; import com.ct108.open.thm.test.FloatWindowUtil; /** * Created by thm on 2016/8/22. */ public class BaseActivity extends Activity{ @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); } @Override protected void onResume() { super.onResume(); LogUtil.d("BaseActivity onResume"); if(FloatWindowUtil.getInstance().getService() == null){ LogUtil.e("BaseActivity getService() == null"); return; } if(FloatWindowUtil.getInstance().getService().isHide()){ LogUtil.d("BaseActivity showFloat"); FloatWindowUtil.getInstance().getService().showFloat(); } } @Override protected void onPause() { super.onPause(); } @Override protected void onStop() { super.onStop(); String pkg = new GetTopInfo(this).getPkgName(); LogUtil.d("BaseActivity onStop & pkg = "+ pkg); if(!pkg.equals("com.uc108.doudizhu")){ if(FloatWindowUtil.getInstance().getService() == null) return; FloatWindowUtil.getInstance().getService().hide(); LogUtil.d("BaseActivity hide"); } } @Override protected void onDestroy() { super.onDestroy(); } }
工具類GetTopInfo(),獲取棧頂Acativity的包名。
public class GetTopInfo {
private final Context context;
public GetTopInfo(Context context) {
this.context = context;
}
public String getPkgName(){
if(CollectionUtils.isNotEmpty(get()))
return get()[0];
return "";
}
public String[] get() {
LogUtil.d("GetTopInfo curSDK_INT = "+Build.VERSION.SDK_INT);
if (Build.VERSION.SDK_INT < 21)
return getPreLollipop();
else
return getLollipop();
}
private String[] getPreLollipop() {
@SuppressWarnings("deprecation")
List<ActivityManager.RunningTaskInfo> tasks =
activityManager().getRunningTasks(1);
ActivityManager.RunningTaskInfo currentTask = tasks.get(0);
ComponentName currentActivity = currentTask.topActivity;
return new String[] { currentActivity.getPackageName() };
}
@TargetApi(Build.VERSION_CODES.KITKAT)
private String[] getLollipop() {
final int PROCESS_STATE_TOP = 2;
try {
Field processStateField = ActivityManager.RunningAppProcessInfo.class.getDeclaredField("processState");
List<ActivityManager.RunningAppProcessInfo> processes =
activityManager().getRunningAppProcesses();
for (ActivityManager.RunningAppProcessInfo process : processes) {
if (process.importance <= ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND
&& process.importanceReasonCode == 0) {
int state = processStateField.getInt(process);
if (state == PROCESS_STATE_TOP)
return process.pkgList;
}
}
} catch (NoSuchFieldException | IllegalAccessException e) {
throw new RuntimeException(e);
}
return new String[] { };
}
private ActivityManager activityManager() {
return (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
}
public boolean isNotEmpty(Object[] array) {
if(array == null)
return false;
if(array.length == 0)
return false;
else
return true;
}
}