将uiimage转换为负色第二次崩溃的应用程序 [英] converting uiimage to negative colors 2nd time crashes the app

问题描述

我想显示一张含有负片图片和正常图片的动画。
开始时，调用getPhoto方法，用户可以从库中获取图片或从相机中获取图片。

I want show an animation with a negative image and a normal image. To start, the getPhoto method is called and the user can get an image from library or take one with the camera.

当动画运行时

-(IBAction) getPhoto:(id) sender {

    UIImagePickerController * picker = [[UIImagePickerController alloc] init];
    picker.delegate = self;

    if((UIButton *) sender == choosePhotoBtn) {
        picker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
    } else {
        picker.sourceType = UIImagePickerControllerSourceTypeCamera;
    }

    [self presentModalViewController:picker animated:YES];

    [picker release];

}
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {

[picker dismissModalViewControllerAnimated:YES];

UIImage *negative = [self convertImageToNegative:[info objectForKey:@"UIImagePickerControllerOriginalImage"]];

imageView.animationImages = [NSArray arrayWithObjects: negative,[info objectForKey:@"UIImagePickerControllerOriginalImage"],nil];

imageView.animationDuration = 60.0; // seconds
imageView.animationRepeatCount = 1; // 0 = loops forever
[imageView startAnimating]; 

[negative release];
}

- (UIImage *)convertImageToNegative:(UIImage *)image{

UIGraphicsBeginImageContext(image.size);

CGContextSetBlendMode(UIGraphicsGetCurrentContext(), kCGBlendModeCopy);

[image drawInRect:CGRectMake(0, 0, image.size.width, image.size.height)];

CGContextSetBlendMode(UIGraphicsGetCurrentContext(), kCGBlendModeDifference);

CGContextSetFillColorWithColor(UIGraphicsGetCurrentContext(),[UIColor whiteColor].CGColor);

CGContextFillRect(UIGraphicsGetCurrentContext(), CGRectMake(0, 0, image.size.width, image.size.height));

UIImage *returnImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();    

return returnImage;
}

仪器 - CPU采样器显示使用率为100％。
我如何防止这种情况？

Instruments - CPU Sampler shows that the usage is 100%. How can i prevent this?

推荐答案

UIGraphicsGetImageFromCurrentImageContext（）返回一个自动释放的对象，所以不要在离开函数之前释放它。当执行返回到运行循环时，自动释放池将为您执行。

You release the image twice. UIGraphicsGetImageFromCurrentImageContext() returns an autoreleased object, so don't release it just before leaving the function. The autorelease pool will do that for you when execution returns to the run loop.

这篇关于将uiimage转换为负色第二次崩溃的应用程序的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！