How to convert image path to uiimage using ALAsset

问题:

My iphone application have a array for store the image path selected by user form gallery. I want use ALAssetsLibrary to convert all image path in array to uiimage. How can I do this action? I try used loop, but can not. Thx for the help.

ALAssetsLibrary *library = [[[ALAssetsLibrary alloc] init] autorelease];
[library assetForURL:[filePath objectAtIndex:0] resultBlock:^(ALAsset *asset) {
    UIImage *image = [UIImage imageWithCGImage:[[asset defaultRepresentation] fullResolutionImage]];
    [fileImage addObject:image];
} failureBlock:^(NSError *error) {

}];

回答1:

Please use the below code

typedef void (^ALAssetsLibraryAssetForURLResultBlock)(ALAsset *asset);
typedef void (^ALAssetsLibraryAccessFailureBlock)(NSError *error);    
                       
ALAssetsLibraryAssetForURLResultBlock resultblock = ^(ALAsset *myasset){
                       
 ALAssetRepresentation *rep = [myasset defaultRepresentation];
 CGImageRef iref = [rep fullResolutionImage];
            
 if (iref){

         dispatch_async(dispatch_get_main_queue(), ^{
             UIImage *myImage = [UIImage imageWithCGImage:iref scale:[rep scale] orientation:(UIImageOrientation)[rep orientation]];
             [fileImage addObject:myImage];
             //binding ur UI elements in main queue for fast execution
             //self.imageView.image = myImage;
         });

                                
         }      
};      
                       
ALAssetsLibraryAccessFailureBlock failureblock  = ^(NSError *myerror){
                       
     //failed to get image.
};                          
                       
ALAssetsLibrary* assetslibrary = [[[ALAssetsLibrary alloc] init] autorelease];
[assetslibrary assetForURL:[filePath objectAtIndex:0] resultBlock:resultblock failureBlock:failureblock];

Note: Make sure that, your [filePath objectAtIndex:0] will be a NSUrl object. Please convert it to NSUrl, if not.

Example:

ALAssetsLibrary* assetslibrary = [[[ALAssetsLibrary alloc] init] autorelease];

NSURL myAssetUrl = [NSURL URLWithString:[filePath objectAtIndex:0]];

assetslibrary assetForURL:myAssetUrl resultBlock:resultblock failureBlock:failureblock];