将图片保存到库时iPhone应用程序崩溃

我在iphone上测试应用程序时遇到问题。 我有一种方法，可以将四幅图像合并为一幅，并将其保存到照片库中：

    - (UIImage *)combineImages{
        UIImage *image1 = firstImgView.image;
        UIImage *image2 = secondImgView.image;
        UIImage *image3 = thirdImgView.image;
        UIImage *image4 = fourthImgView.image;

        UIGraphicsBeginImageContext(image1.size);

        [image1 drawInRect:CGRectMake(0, 0, image1.size.width, image1.size.height)];
        [image2 drawInRect:CGRectMake(0, 0, image2.size.width, image2.size.height)];
        [image3 drawInRect:CGRectMake(0, 0, image3.size.width, image3.size.height)];
        [image4 drawInRect:CGRectMake(0, 0, image4.size.width, image4.size.height)];

        UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();

        UIGraphicsEndImageContext();

        return resultingImage;  
    }
//save actual design in photo library
- (void)savePicture{
    UIImage *myImage = [self combineImages];
    UIImageWriteToSavedPhotosAlbum(myImage, self, @selector(imageSavedToPhotosAlbum:didFinishSavingWithError:contextInfo:), self); 
}

//feedback if picture saving was successfull
- (void)imageSavedToPhotosAlbum:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {  
    NSString *message;  
    NSString *title;  
    if (!error) {  
        title   = NSLocalizedString(@"Image saved", @"");  
       // message = NSLocalizedString(@"Your image was saved", @"");  
    } else {  
        title   = NSLocalizedString(@"Error", @"");  
        message = [error description];  
    }  
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:title  
                                                    message:message  
                                                   delegate:nil  
                                          cancelButtonTitle:NSLocalizedString(@"Ok", @"")  
                                          otherButtonTitles:nil];  
    [alert show];  
    [alert release];  
} 

当我想要测试它时，我得到以下错误：

Program received signal:  “EXC_BAD_ACCESS”.
Data Formatters temporarily unavailable, will re-try after a 'continue'. (Not safe to call dlopen at this time.)
warning: Cancelling call - objc code on the current thread's stack makes this unsafe.

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在模拟器中，它工作正常。

如果图像总数超过1k x 1k像素，那么我猜您的设备内存不足。模拟器有更多的可用内存。在模拟器构建上运行内存分配工具，查看图像和合成操作实际消耗的峰值。

我的猜测是，在将组合图像传递给UIImageWriteToSavedPhotosAlbum之前，必须保留组合图像。合并后的图像将自动删除，并且可以在实际保存之前将其释放。试试这个：

//save actual design in photo library
- (void)savePicture{
    UIImage *myImage = [self combineImages];
    [myImage retain];
    UIImageWriteToSavedPhotosAlbum(myImage, self, @selector(imageSavedToPhotosAlbum:didFinishSavingWithError:contextInfo:), self); 
}

//feedback if picture saving was successfull
- (void)imageSavedToPhotosAlbum:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {  
    [image release];
    // ...
}

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发现错误。。。有点愚蠢的错误。 就是那条线

 // message = NSLocalizedString(@"Your image was saved", @""); 

我不应该把它评论掉。

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现在一切正常。

Hi Gobra，图像已保存到库中，但我没有收到“已保存警报”，应用程序随后被冻结。