用户界面命令在IBAction中跳过
这是我的代码：
-(IBAction)saveDownloadedImage { NSLog(@"Test"); EXECUTED indicatorView.hidden = NO; NOT EXECUTED [indicatorView startAnimating]; NOT EXECUTED [statusLabel setText:@"WHY?"]; NOT EXECUTED [currentPicture setImage:[imageView image]]; EXECUTED ImageFileManager *fileManager = [[ImageFileManager alloc] init]; EXECUTED [fileManager saveImageToDisk:currentPicture]; EXECUTED indicatorView.hidden = YES; [statusLabel setText:@"Image saved successfully."]; EXECUTED saveButton.enabled = NO; EXECUTED }
节约的时间大约需要5秒钟。 所以在用户界面中看到这个指标是很正常的。 但没有任何反应！ 任何想法？
一切都被执行。 你的问题是saveImageToDisk调用是同步的，你从UI线程调用它。 当你阻塞UI线程时，什么都不会重新绘制。 指示器被显示，但是直到IBAction返回时它才能被拖到屏幕上。
您必须asynchronous调用保存方法。
阻塞UI线程从来不是一个好主意。
编辑：请参阅以下问题的答案以获得正确的解决scheme： 在ios中asynchronous调用数据库
编辑2：可能的解决scheme之一（未testing）
-(IBAction)saveDownloadedImage { indicatorView.hidden = NO; //Note you can use hidesWhenStopped property for this [indicatorView startAnimating]; [statusLabel setText:@"BECAUSE..."]; [currentPicture setImage:[imageView image]]; [NSThread detachNewThreadSelector:@selector(save) toTarget:self withObject:nil] } - (void)save { @autoreleasepool { ImageFileManager *fileManager = [[ImageFileManager alloc] init]; [fileManager saveImageToDisk:currentPicture]; [self performSelectorOnMainThread:@selector(updateUI) withObject:nil waitUntilDone:NO]; } } - (void)updateUI { indicatorView.hidden = YES; [statusLabel setText:@"Image saved successfully."]; saveButton.enabled = NO; }
你确定吗？
1）indicatorView和statusLabel不为空，并且
2）indicatorView和statusLabel作为subview添加到self.view？
在我的知觉你正在开始活动指标主线程。
而是在主线程上显示指标
你应该在下面的独立线程上调用Indicator。
-(IBAction)saveDownloadedImage { NSLog(@"Test"); EXECUTED commented below code //indicatorView.hidden = NO; NOT EXECUTED // [indicatorView startAnimating]; NOT EXECUTED //instead of main thread create new Thread as Below [NSThread detachNewThreadSelector:@selector(showloader) toTarget:self withObject:nil]; [statusLabel setText:@"WHY?"]; NOT EXECUTED [currentPicture setImage:[imageView image]]; EXECUTED ImageFileManager *fileManager = [[ImageFileManager alloc] init]; EXECUTED [fileManager saveImageToDisk:currentPicture]; EXECUTED [statusLabel setText:@"Image saved successfully."]; EXECUTED saveButton.enabled = NO; [indicatorView stopAnimating:YES]; indicatorView.hidden = YES; } //Custome method For shoing the Indicator. -(void)showloader{ //call below method here indicatorView object created already. [indicatorView startAnimating] } It'll definitely work
你需要像这样向发件人声明你的方法
-(IBAction)saveDownloadedImage:(id)sender