From 16d661488a1e4d01c5e9f94d5b0b0c0f937afaea Mon Sep 17 00:00:00 2001 From: Eli Wang Date: Wed, 9 May 2012 17:33:38 +0800 Subject: [PATCH] Update README.md with syntax color. --- README.md | 120 ++++++++++++++++++++++++++++++------------------------ 1 file changed, 67 insertions(+), 53 deletions(-) diff --git a/README.md b/README.md index 8aa5206e..40ef57cd 100644 --- a/README.md +++ b/README.md @@ -64,41 +64,44 @@ Just #import the UIImageView+WebCache.h header, and call the setImageWithURL:pla method from the tableView:cellForRowAtIndexPath: UITableViewDataSource method. Everything will be handled for you, from async downloads to caching management. - #import "UIImageView+WebCache.h" +```objective-c +#import "UIImageView+WebCache.h" - ... +... - - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath +- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath +{ + static NSString *MyIdentifier = @"MyIdentifier"; + + UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MyIdentifier]; + + if (cell == nil) { - static NSString *MyIdentifier = @"MyIdentifier"; - - UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MyIdentifier]; - - if (cell == nil) - { - cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault - reuseIdentifier:MyIdentifier] autorelease]; - } - - // Here we use the new provided setImageWithURL: method to load the web image - [cell.imageView setImageWithURL:[NSURL URLWithString:@"http://www.domain.com/path/to/image.jpg"] - placeholderImage:[UIImage imageNamed:@"placeholder.png"]]; - - cell.textLabel.text = @"My Text"; - return cell; + cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault + reuseIdentifier:MyIdentifier] autorelease]; } + // Here we use the new provided setImageWithURL: method to load the web image + [cell.imageView setImageWithURL:[NSURL URLWithString:@"http://www.domain.com/path/to/image.jpg"] + placeholderImage:[UIImage imageNamed:@"placeholder.png"]]; + + cell.textLabel.text = @"My Text"; + return cell; +} +``` + ### Using blocks If your project's deployement target is set to iOS 4+, you may want to use the success/failure blocks to be notified when image have been retrieved from cache. - - // Here we use the new provided setImageWithURL: method to load the web image - [cell.imageView setImageWithURL:[NSURL URLWithString:@"http://www.domain.com/path/to/image.jpg"] - placeholderImage:[UIImage imageNamed:@"placeholder.png"] - success:^(UIImage *image) {... success code here ...} - failure:^(NSError *error) {... failure code here ...}]; +```objective-c +// Here we use the new provided setImageWithURL: method to load the web image +[cell.imageView setImageWithURL:[NSURL URLWithString:@"http://www.domain.com/path/to/image.jpg"] + placeholderImage:[UIImage imageNamed:@"placeholder.png"] + success:^(UIImage *image) {... success code here ...} + failure:^(NSError *error) {... failure code here ...}]; ]; +``` Note: neither your success nor failure block will be call if your image request is canceled before completion. @@ -110,34 +113,39 @@ from web image downloading with caching in another context than a UIView (ie: wi Here is a simple example of how to use SDWebImageManager: - SDWebImageManager *manager = [SDWebImageManager sharedManager]; +```objective-c +SDWebImageManager *manager = [SDWebImageManager sharedManager]; - UIImage *cachedImage = [manager imageWithURL:url]; +UIImage *cachedImage = [manager imageWithURL:url]; - if (cachedImage) - { - // Use the cached image immediatly - } - else - { - // Start an async download - [manager downloadWithURL:url delegate:self]; - } +if (cachedImage) +{ + // Use the cached image immediatly +} +else +{ + // Start an async download + [manager downloadWithURL:url delegate:self]; +} +``` Your class will have to implement the SDWebImageManagerDelegate protocol, and to implement the webImageManager:didFinishWithImage: method from this protocol: - - (void)webImageManager:(SDWebImageManager *)imageManager didFinishWithImage:(UIImage *)image - { - // Do something with the downloaded image - } +```objective-c +- (void)webImageManager:(SDWebImageManager *)imageManager didFinishWithImage:(UIImage *)image +{ + // Do something with the downloaded image +} +``` ### Using Asynchronous Image Downloader Independently It is possible to use the async image downloader independently. You just have to create an instance of SDWebImageDownloader using its convenience constructor downloaderWithURL:delegate:. - - downloader = [SDWebImageDownloader downloaderWithURL:url delegate:self]; +```objective-c +downloader = [SDWebImageDownloader downloaderWithURL:url delegate:self]; +``` The download will start immediately and the imageDownloader:didFinishWithImage: method from the SDWebImageDownloaderDelegate protocol will be called as soon as the download of image is completed. @@ -156,7 +164,9 @@ doesn't currently own the image. You are thus responsible for generating and cac key is an application unique identifier for the image to cache. It is generally the absolute URL of the image. - UIImage *myCachedImage = [[SDImageCache sharedImageCache] imageFromKey:myCacheKey]; +```objective-c +UIImage *myCachedImage = [[SDImageCache sharedImageCache] imageFromKey:myCacheKey]; +``` By default SDImageCache will lookup the disk cache if an image can't be found in the memory cache. You can prevent this from happening by calling the alternative method imageFromKey:fromDisk: with a @@ -164,7 +174,9 @@ negative second argument. To store an image into the cache, you use the storeImage:forKey: method: - [[SDImageCache sharedImageCache] storeImage:myImage forKey:myCacheKey]; +```objective-c +[[SDImageCache sharedImageCache] storeImage:myImage forKey:myCacheKey]; +``` By default, the image will be stored in memory cache as well as on disk cache (asynchronously). If you want only the memory cache, use the alternative method storeImage:forKey:toDisk: with a negative @@ -179,17 +191,19 @@ takes the NSURL as input, and output a cache key NSString. The following example sets a filter in the application delegate that will remove any query-string from the URL before to use it as a cache key: - - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions +```objective-c +- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions +{ + [[SDWebImageManager sharedManager] setCacheKeyFilter:^(NSURL *url) { - [[SDWebImageManager sharedManager] setCacheKeyFilter:^(NSURL *url) - { - url = [[[NSURL alloc] initWithScheme:url.scheme host:url.host path:url.path] autorelease]; - return [url absoluteString]; - }]; + url = [[[NSURL alloc] initWithScheme:url.scheme host:url.host path:url.path] autorelease]; + return [url absoluteString]; + }]; - // Your app init code... - return YES; - } + // Your app init code... + return YES; +} +``` Common Problems