iOS 根据图片URL从本地相册获取图片

电玩女神 2022-01-05 16:19 343阅读 0赞

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];
    }

转载于:https://www.cnblogs.com/pretty-guy/p/4548761.html