最近做一個聊天的項目，需要發送圖片后讀取本地圖片顯示到列表里。剛開始的時候，天真的認為可以用SDWebImage直接加載，然后並不能行。
於是在網上搜了搜，如何根據從相冊獲取的UIImagePickerControllerReferenceURL讀取圖片， 代碼如下：
#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];
}
彈出圖片選擇器
- (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];
}
回調
- (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) {
//進行UI修改
dispatch_sync(dispatch_get_main_queue(), ^{
_imageView.image = [[UIImage alloc] initWithCGImage:iref];
});
}
}
failureBlock:^(NSError *error) {
NSLog(@"從圖庫獲取圖片失敗: %@",error);
}];
} @catch (NSException *e) {
NSLog(@"從圖庫獲取圖片異常: %@", e);
}
}
});
}
[picker dismissViewControllerAnimated:YES completion:nil];
}