Question

我想要显示带有负片图像和普通图像的动画。首先，调用getPhoto方法，用户可以从库中获取图像或使用相机拍摄图像。

当动画运行时，我希望能够将图像设置为新图像，但随后应用程序崩溃。

-(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％。我该如何防止这种情况？

Answer 1

此方法将为您提供在参数

中指定的图像的反转图像

-(UIImage *) getImageWithInvertedPixelsOfImage:(UIImage *)image {
    UIGraphicsBeginImageContextWithOptions(image.size, NO, 2);
    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 * result = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return result;
}

像这样使用：

yourImage.image = [self getImageWithInvertedPixelsOfImage:yourImage.image];

Answer 2

您将图像释放两次。 UIGraphicsGetImageFromCurrentImageContext（）返回一个自动释放的对象，因此在离开函数之前不要释放它。当执行返回到运行循环时，自动释放池将为您执行此操作。

将uiimage转换为负面颜色第二次崩溃应用程序

2 个答案: