最近做一个聊天的项目，需要发送图片后读取本地图片显示到列表里。刚开始的时候，天真的认为可以用SDWebImage直接加载，然后并不能行。
于是在网上搜了搜，如何根据从相册获取的UIImagePickerControllerReferenceURL读取图片， 代码如下：
#import "ViewController.h"
#import <AssetsLibrary/AssetsLibrary.h>
@interface ViewController ()<UINavigationControllerDelegate, UIImagePickerControllerDelegate>
- (IBAction)showImagePickerVC:(id)sender;
@property (weak, nonatomic) IBOutlet UIImageView *imageView;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
}
弹出图片选择器
- (IBAction)showImagePickerVC:(id)sender {
UIImagePickerController *imagePickerVC = [[UIImagePickerController alloc] init];
imagePickerVC.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
imagePickerVC.allowsEditing = YES;
imagePickerVC.delegate = self;
[self presentViewController:imagePickerVC animated:YES completion:nil];
}
回调
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
NSLog(@"%@", info);
NSURL *imagePath = info[@"UIImagePickerControllerReferenceURL"];
if ([[[imagePath scheme] lowercaseString] isEqualToString:@"assets-library"]) {
// Load from asset library async
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
@autoreleasepool {
@try {
ALAssetsLibrary *assetslibrary = [[ALAssetsLibrary alloc] init];
[assetslibrary assetForURL:imagePath
resultBlock:^(ALAsset *asset){
ALAssetRepresentation *rep = [asset defaultRepresentation];
CGImageRef iref = [rep fullScreenImage];
if (iref) {
//进行UI修改
dispatch_sync(dispatch_get_main_queue(), ^{
_imageView.image = [[UIImage alloc] initWithCGImage:iref];
});
}
}
failureBlock:^(NSError *error) {
NSLog(@"从图库获取图片失败: %@",error);
}];
} @catch (NSException *e) {
NSLog(@"从图库获取图片异常: %@", e);
}
}
});
}
[picker dismissViewControllerAnimated:YES completion:nil];
}
原文：http://www.cnblogs.com/pretty-guy/p/4548761.html