Question

我正在开发一个应用程序，我需要捕获多个图像并将它们存储在一个文件夹中。当图像超出时，应用程序崩溃。而在拍摄图像时，iPhone会慢一点。请有人帮我这个。

捕捉图像的代码

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

[self.navigationController presentModalViewController:picker animated:YES];

将图像添加到文件中的代码

NSString  *pngImagePath =
[[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES) lastObject]
stringByAppendingPathComponent:[NSString
stringWithFormat:@"%@.png",imageName]];

    [dataImage writeToFile:pngImagePath atomically:YES];

Answer 1

此处，以此代码为例，在您将图像显示在屏幕上之前调整图像大小：

+ (UIImage*)imageWithImage:(UIImage*)image
          scaledToSize:(CGSize)newSize;
{
    UIGraphicsBeginImageContext( newSize );
    [image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
    UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return newImage;
}

请注意，在将图像保存到磁盘之前，还应该缩小图像：

UIImage *image = YOUR_IMAGE;
NSData *imageData = UIImageJPEGRepresentation(image, .06); // Here's the level of compression

Answer 2

尝试使用@autoreleasepool一次，可能是因为一些内存泄漏。 @autoreleasepool维持一定程度..

 @autoreleasepool
    {
      // any allocation for UIImage if u have just bring inside the autoreleasepool
        NSString  *pngImagePath =
        [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
        NSUserDomainMask, YES) lastObject]
        stringByAppendingPathComponent:[NSString
        stringWithFormat:@"%@.png",imageName]];
        [dataImage writeToFile:pngImagePath atomically:YES];
    }

iPhone在捕获多个图像时崩溃，并且速度也会降低

2 个答案: