Objective c UIActivityViewController打开和关闭事件
我正试图连接到UIActivityViewController,因为我需要在视图打开时停止一些代码的运行 当视图关闭时,我需要重新开始上课Objective c UIActivityViewController打开和关闭事件,objective-c,uiactivityviewcontroller,Objective C,Uiactivityviewcontroller,我正试图连接到UIActivityViewController,因为我需要在视图打开时停止一些代码的运行 当视图关闭时,我需要重新开始上课 UIActivityViewController *activityController = [[UIActivityViewController alloc] initWithActivityItems:activityItems applicationActivities:nil]; [activityController setTitle:code];
UIActivityViewController *activityController = [[UIActivityViewController alloc] initWithActivityItems:activityItems applicationActivities:nil];
[activityController setTitle:code];
[activityController setExcludedActivityTypes:self.excludedItems];
[activityController setCompletionHandler:^(NSString *activityType, BOOL completed) {
self.label.text = @"Scanning...";
[self.qrScannerView start];
}];
当它打开时,我需要停止它:
[self presentViewController:activityController animated:YES completion:^{
[self.qrScannerView stop];
}];
这似乎只工作一次,但之后它将继续运行。我做错了什么?这是由于我的自定义类过早更改了stopped和start的值,因此我无法关闭。可能与块中对self的引用有关?啊。我想出来了。只有当_canScan是正确的布尔值时,我的启动和停止事件才会触发。看起来他们比完工时间要快。