将NSDATA转换为UIImage时速度慢 [英] Slow speed while converting NSDATA to UIImage

问题描述

我在NSDATA形式的数组中有一些图像。我在页面控制器示例6中一次显示它们。

I have some images in the array in the form of NSDATA.and i am showing them on page in page controller example 6 at a time.

但它们是花时间转换为UIImage，这就是为什么滚动得慢，我们还有其他选择吗？

But they are taking time to get convert in to UIImage that's why scrolling get slow dowwn is we have any other option?

我正在使用以下代码将它们转换为NSDATA。

i am using following code to convert them into NSDATA.

[UImage imageWithData：data];

[UImage imageWithData:data];

推荐答案

来自 http://www.switchonthecode.com/tutorials/loading-images-asynchronously- on-iphone-using-nsinvocationoperation ：

在主线程中：

NSOperationQueue *queue = [NSOperationQueue new];
NSInvocationOperation *operation = [[NSInvocationOperation alloc] 
                                      initWithTarget:self
                                                 selector:@selector(loadImage) 
                                                    object:nil];
[queue addOperation:operation]; 
[operation release];

所需的其他方法：

- (void)loadImage {
  NSData* imageData = //however you're getting your NSData
  UIImage* image = [[[UIImage alloc] initWithData:imageData] autorelease];
  [imageData release];
  [self performSelectorOnMainThread:@selector(displayImage:) withObject:image waitUntilDone:NO];
}

- (void)displayImage:(UIImage *)image {
  [imageView setImage:image]; //UIImageView
}

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