toast 在應用關閉通知顯示時,某些手機上會不在顯示toast;
原因簡單的說就是toast使用了通知管理器INotificationManager類,而此類因爲禁止了通知欄權限而不顯示toast; 有興趣的可以追下源碼;
重點說下3種解決方法把:
- 提示用戶打開通知欄權限
var CHECK_OP_NO_THROW: String = "checkOpNoThrow"
var OP_POST_NOTIFICATION: String = "OP_POST_NOTIFICATION"
fun isNotificationEnabled(): Boolean {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
return (Utils.getContext().getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager).areNotificationsEnabled()
} else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
var mAppOps = Utils.getContext().getSystemService(Context.APP_OPS_SERVICE)
var appInfo: ApplicationInfo = Utils.getContext().getApplicationInfo()
var pkg: String = Utils.getContext().getApplicationContext().getPackageName()
var uid: Int = appInfo.uid
var appOpsClass: Class<*>? = null
/* Context.APP_OPS_MANAGER */
try {
appOpsClass = Class.forName(AppOpsManager::class.java.name)
var checkOpNoThrowMethod: Method = appOpsClass.getMethod(CHECK_OP_NO_THROW, Integer.TYPE, Integer.TYPE, String::class.java)
var opPostNotificationValue: Field = appOpsClass.getDeclaredField(OP_POST_NOTIFICATION)
var value: Int = opPostNotificationValue.get(Integer::class.java) as Int
return (checkOpNoThrowMethod.invoke(mAppOps, value, uid, pkg) as Int == AppOpsManager.MODE_ALLOWED)
} catch (e: Exception) {
e.printStackTrace()
}
}
return true
}
- 完全自定義toast或者彈框,規避通知管理器限制
INotificationManager根據包名判斷提示權限,使用動態代理使用android替換包名達到允許彈框的目的;
/**
* 顯示系統Toast
*/
private static void showSystemToast(Toast toast){
try{
Method getServiceMethod = Toast.class.getDeclaredMethod("getService");
getServiceMethod.setAccessible(true);
final Object iNotificationManager = getServiceMethod.invoke(null);
Class iNotificationManagerCls = Class.forName("android.app.INotificationManager");
Object iNotificationManagerProxy = Proxy.newProxyInstance(toast.getClass().getClassLoader(), new Class[]{iNotificationManagerCls}, new InvocationHandler() {
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
// 強制使用系統Toast
// 華爲p20 pro上爲enqueueToastEx
if("enqueueToast".equals(method.getName())
|| "enqueueToastEx".equals(method.getName())){
args[0] = "android";
}
return method.invoke(iNotificationManager, args);
}
});
Field sServiceFiled = Toast.class.getDeclaredField("sService");
sServiceFiled.setAccessible(true);
sServiceFiled.set(null, iNotificationManagerProxy);
toast.show();
}catch (Exception e){
e.printStackTrace();
}
}
個人偏向第三種動態代理的方案,具體使用判斷是否開啓通知欄權限使用第一種或者第三種方案;
記錄下toast爲什麼打不開的原因吧, read the fuck source code ~
--------------------------------toast 的 show方法----------------------------
最終獲取 `NotificationManagerService` service;
/**
* Show the view for the specified duration.
*/
public void show() {
if (mNextView == null) {
throw new RuntimeException("setView must have been called");
}
INotificationManager service = getService();
String pkg = mContext.getOpPackageName();
TN tn = mTN;
tn.mNextView = mNextView;
try {
service.enqueueToast(pkg, tn, mDuration);
} catch (RemoteException e) {
// Empty
}
}
static private INotificationManager getService() {
if (sService != null) {
return sService;
}
sService = INotificationManager.Stub.asInterface(ServiceManager.getService("notification"));
return sService;
}
---------------------NotificationManagerService 的 enqueueToast 方法----------------------
public void enqueueToast(String pkg, ITransientNotification callback, int duration)
{
if (DBG) {
Slog.i(TAG, "enqueueToast pkg=" + pkg + " callback=" + callback + " duration=" + duration);
}
if (pkg == null || callback == null) {
Slog.e(TAG, "Not doing toast. pkg=" + pkg + " callback=" + callback);
return ;
}
//通過動態代理更改了包名爲android後,isSystemToasta爲true,可規避下面的reture;
final boolean isSystemToast = isCallerSystem() || ("android".equals(pkg));
final boolean isPackageSuspended = isPackageSuspendedForUser(pkg, Binder.getCallingUid());
//此行會根據包名判斷通知欄的權限是否禁用;
if (ENABLE_BLOCKED_TOASTS && (!noteNotificationOp(pkg, Binder.getCallingUid())
|| isPackageSuspended)) {
if (!isSystemToast) {
Slog.e(TAG, "Suppressing toast from package " + pkg
+ (isPackageSuspended? " due to package suspended by administrator." : " by user request."));
return;
}
}
synchronized (mToastQueue) {
int callingPid = Binder.getCallingPid();
long callingId = Binder.clearCallingIdentity();
try {
ToastRecord record;
int index = indexOfToastLocked(pkg, callback);
// If it's already in the queue, we update it in place, we don't
// move it to the end of the queue.
if (index >= 0) {
record = mToastQueue.get(index);
record.update(duration);
} else {
// Limit the number of toasts that any given package except the android
// package can enqueue. Prevents DOS attacks and deals with leaks.
if (!isSystemToast) {
int count = 0;
final int N = mToastQueue.size();
for (int i=0; i<N; i++) {
final ToastRecord r = mToastQueue.get(i);
if (r.pkg.equals(pkg)) {
count++;
if (count >= MAX_PACKAGE_NOTIFICATIONS) {
Slog.e(TAG, "Package has already posted " + count
+ " toasts. Not showing more. Package=" + pkg);
return;
}
}
}
}
record = new ToastRecord(callingPid, pkg, callback, duration);
mToastQueue.add(record);
index = mToastQueue.size() - 1;
keepProcessAliveLocked(callingPid);
}
// If it's at index 0, it's the current toast. It doesn't matter if it's
// new or just been updated. Call back and tell it to show itself.
// If the callback fails, this will remove it from the list, so don't
// assume that it's valid after this.
if (index == 0) {
showNextToastLocked();
}
} finally {
Binder.restoreCallingIdentity(callingId);
}
}
}
解決方法很巧妙,實測可以用,學習了;
