iOS third-party class library-sdwebimage use

Sdwebimage use--a class library to manage remote picture loading

Sdwebimage is hosted on GitHub. Https://github.com/rs/SDWebImage

This class library provides a uiimageview category to support the loading of remote pictures from the network.

Features such as cache management, asynchronous download, same URL download count control, and optimization.

When you add a Sdwebimage class library to your project, you must be aware that you need to add mapkit.framework, because Mkannotationview+webcache.h relies on the framework.

Use the Demo code:

1.UITableView using Uiimageview+webcache Class (Basic application, one category of Uiimageview)

Premise #import Import the Uiimageview+webcache.h file, and then under TableView Cellforrowatindexpath: Method:

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2. #import "Uiimageview+webcache.h"
6. -(UITableViewCell *) TableView: (UITableView *) TableView Cellforrowatindexpath: (Nsindexpath *) Indexpath
8. {
10. static NSString *myidentifier = @"Myidentifier";
14. UITableViewCell *cell = [TableView dequeuereusablecellwithidentifier:myidentifier];
18. if (cell = = nil)
20. {
22. cell = [[[UITableViewCell alloc] Initwithstyle:uitableviewcellstyledefault
24. Reuseidentifier:myidentifier] autorelease];
26. }
30. //Here we use the new provided Setimagewithurl:method to load the Web image
32. [Cell.imageview setimagewithurl:[nsurl urlwithstring:@"http://www.domain.com/path/to/image.jpg"]
34. Placeholderimage:[uiimage imagenamed:@"Placeholder.png"];
38. Cell.textLabel.text = @"My text";
40. return cell;
42. }

Basic code:

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1. [ImageView setimagewithurl:[nsurl urlwithstring:@<a href="Http://www.domain.com/path/image.jpg" >http://  www.domain.com/path/image.jpg</a>]];

For the ios4+ target platform, you can also use the following block statements:

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2. Here we use the new provided Setimagewithurl:method to load the Web image
4. [Cell.imageview setimagewithurl:[nsurl urlwithstring:@"http://www.domain.com/path/to/image.jpg"]
6. Placeholderimage:[uiimage imagenamed:@"Placeholder.png"]
8. success:^ (UIImage *image) {... success code here ...}
10. failure:^ (Nserror *error) {... failure code here ...}];

2. Use the Sdwebimagemanager class: You can do some asynchronous loading work.

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2. Sdwebimagemanager *manager = [Sdwebimagemanager Sharedmanager];
4. UIImage *cachedimage = [manager Imagewithurl:url]; //Load the pictures that need to be cached in
6. if (cachedimage) {
8. //If the cache is hit, make a direct use of the cached picture for action
10. //Use the cached image immediatly
12. } Else {
14. //If the cache is not hit, download a picture of the specified network location and give a delegate method
16. //Start an async download
18. [Manager Downloadwithurl:url Delegate:self];
20. }

Of course your class wants to implement the Sdwebimagemanagerdelegate protocol, and to implement the webimagemanager:didfinishwithimage of the Protocol : method.

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1. When the download is complete, call the callback method so that the downloaded picture is displayed
2. -(void) Webimagemanager: (Sdwebimagemanager *) Imagemanager didfinishwithimage: (UIImage *) Image {
3. //Do something with the downloaded image
4. }

3. Standalone asynchronous image download
You may use asynchronous image download alone, you must use downloaderwithurl:delegate: To create a Sdwebimagedownloader instance.

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1. Downloader =[sdwebimagedownloader Downloaderwithurl:url delegate:self];

This method of Sdwebimagedownloaderdelegate protocol imagedownloader:didfinishwithimage: The download will start immediately and complete when it is invoked.

4. Stand-alone asynchronous image caching

The Sdimagecache class provides an instance of creating an empty cache and uses method Imageforkey: To find the current cache.

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1. Uiimage*mycachedimage = [[Sdimagecache Sharedimagecache] imagefromkey:mycachekey];

Storing an image to the cache is a way to use Storeimage:forkey:

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1. [[Sdimagecachesharedimagecache] Storeimage:myimage Forkey:mycachekey];

By default, images are stored in the memory cache and in the disk cache. If you want to use StoreImage:forKey:toDisk in memory cache only: The third parameter of the method takes a negative value
To replace.