iOS 使用ALAssetsLibrary保存图片到本地

第一步：添加 AssetsLibrary.framework 框架

第二步：需要使用的类里面导入头文件 #import <AssetsLibrary/AssetsLibrary.h>

第三步：保存网络图片到本地

- (void)viewDidLoad
{
[super viewDidLoad];

UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://pic25.nipic.com/20121209/9252150_194258033000_2.jpg"]]];
[self saveImage:image];

}
- (void)saveImage:(UIImage*)image{
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];

[library writeImageToSavedPhotosAlbum:[image CGImage] orientation:(ALAssetOrientation)image.imageOrientation completionBlock:^(NSURL *assetURL, NSError *error) {
if (error) {
NSLog(@"Save image fail：%@",error);
}else{
NSLog(@"Save image succeed.");
}
}];
}