iphone - 选择图像以在我的整个应用程序中用作UIViewController背景

Question

当我的iPhone应用程序首次运行时，它会要求您从iPhone库中选择一个图像作为整个应用程序的背景。以下是相关代码:

/*
 *   Responds when an image is selected (from browsing)
 */
-(void)imagePickerController:(UIImagePickerController *)picker
didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    NSString *mediaType = [info objectForKey:UIImagePickerControllerMediaType];
    [self dismissModalViewControllerAnimated:YES];
    if ([mediaType isEqualToString:(NSString *)kUTTypeImage])
    {
        //Not really sure what to do here
        UIImage *image = [[UIImage alloc] initWithData:UIImageJPEGRepresentation([info objectForKey:UIImagePickerController], .2)];
    }
}

现在，我要保存该图像(或对此图像的引用)的内容，以便可以在整个应用程序中将其用作 UIViewController的一部分(60％)的背景

self.view.backgroundColor = [UIColor colorWithPatternImage:image];

什么是执行此的最佳/最有效/最简单的方法。我曾考虑过将图像保存到 NSUserDefaults中，但这似乎并不正确，因为 NSUserDefaults仅应用于小型对象。我应该将其保存到磁盘吗？但是，然后每次我搜索时，从磁盘读取数据时我的应用程序就不会真的慢吗？ (如果这是正确的方法，我该怎么做？)

Answer 1

将图像存储在文档目录中
保存图像

- (void)saveImage:(UIImage *)image {
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *savedImagePath = [documentsDirectory stringByAppendingPathComponent:@"savedImage.png"];

    // Convert to Data
    NSData *imageData = UIImagePNGRepresentation(image);
    // write to file
    [imageData writeToFile:savedImagePath atomically:NO];
}

要阅读图像，请使用以下

- (UIImage *)getImage {
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,     NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *getImagePath = [documentsDirectory stringByAppendingPathComponent:@"savedImage.png"];
    UIImage *img = [UIImage imageWithContentsOfFile:getImagePath];
    return img;
}