我使用ZXing作为应用程序,这主要是与ZXing原始代码相同的代码,只是我允许连续扫描几次(即,一旦检测到某些东西,ZXingWidgetController就不会被解雇)。
当我按下调用
的关闭按钮时,我会遇到很长时间的冻结(有时它永远不会结束)- (void)cancelled {
// if (!self.isStatusBarHidden) {
// [[UIApplication sharedApplication] setStatusBarHidden:NO];
// }
[self stopCapture];
wasCancelled = YES;
if (delegate != nil) {
[delegate zxingControllerDidCancel:self];
}
}
带
- (void)stopCapture {
decoding = NO;
#if HAS_AVFF
if([captureSession isRunning])[captureSession stopRunning];
AVCaptureInput* input = [captureSession.inputs objectAtIndex:0];
[captureSession removeInput:input];
AVCaptureVideoDataOutput* output = (AVCaptureVideoDataOutput*)[captureSession.outputs objectAtIndex:0];
[captureSession removeOutput:output];
[self.prevLayer removeFromSuperlayer];
/*
// heebee jeebees here ... is iOS still writing into the layer?
if (self.prevLayer) {
layer.session = nil;
AVCaptureVideoPreviewLayer* layer = prevLayer;
[self.prevLayer retain];
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 12000000000), dispatch_get_main_queue(), ^{
[layer release];
});
}
*/
self.prevLayer = nil;
self.captureSession = nil;
#endif
}
(请注意,删除视图的dismissModalViewController在委托方法中)
只有在我连续进行多次扫描并且仅使用iPhone 4(没有使用4S冻结)时,才会解除冻结,但只会解散冻结
有什么想法吗?
干杯
罗
答案 0 :(得分:22)
根据AV Cam View Controller Example调用startRunning或stopRunning直到会话完成请求的操作才返回。由于您将这些消息发送到主线程上的会话,因此它会冻结所有UI,直到请求的操作完成。我建议您将调用包装在异步调度中,以便视图不会锁定。
- (void)cancelled
{
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
[self stopCapture];
});
//You might want to think about putting the following in another method
//and calling it when the stop capture method finishes
wasCancelled = YES;
if (delegate != nil) {
[delegate zxingControllerDidCancel:self];
}
}