iOS 保存图片和视频

保存图片

使用UIImageWriteToSavedPhotosAlbum方法保存图片到相册

- (void)saveImage:(UIImage *)image {
    UIImageWriteToSavedPhotosAlbum(image, self,
           @selector(UIImageWriteToSavedPhotosAlbum_image:didFinishSavingWithError:contextInfo:), nil);
}

- (void)UIImageWriteToSavedPhotosAlbum_image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo{
    if (error) {
        NSLog(@"UIImageWriteToSavedPhotosAlbum_image %@", error);
    } else {
        NSLog(@"UIImageWriteToSavedPhotosAlbum_image success");
    }
}

使用ALAssetsLibrary框架保存图片到相册

- (void)saveAssetLibraryImage:(UIImage *)image {
    ALAssetsLibrary *lib = [[ALAssetsLibrary alloc] init];
    [lib writeImageToSavedPhotosAlbum:image.CGImage metadata:nil completionBlock:^(NSURL *assetURL, NSError *error) {
        if (error) {
            NSLog(@"saveAssetLibraryImage %@", error);
        } else {
            NSLog(@"saveAssetLibraryImage success");
        }
    }];
}

使用PHPhoto框架保存图片到相册

[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
        [PHAssetChangeRequest creationRequestForAssetFromImage:image];
    } completionHandler:^(BOOL success, NSError * _Nullable error) {
        if (error) {
            NSLog(@"savePhotoLibraryImage %@", error);
        } else {
            NSLog(@"savePhotoLibraryImage success");
        }
    }];

保存视频

使用UISaveVideoAtPathToSavedPhotosAlbum方法保存图片到相册

- (void)saveVideo:(NSURL *)mediaURL {
    UISaveVideoAtPathToSavedPhotosAlbum([mediaURL path], self,
            @selector(UISaveVideoAtPathToSavedPhotosAlbum_videoPath:didFinishSavingWithError:contextInfo:), nil);
}

- (void)UISaveVideoAtPathToSavedPhotosAlbum_videoPath:(NSString *)videoPath didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo{
    if (error) {
        NSLog(@"UISaveVideoAtPathToSavedPhotosAlbum_videoPath %@", error);
    } else {
        NSLog(@"UISaveVideoAtPathToSavedPhotosAlbum_videoPath success");
    }
}

使用ALAssetsLibrary框架保存视频到相册

- (void)saveAssetLibraryVideo:(NSURL *)mediaURL {
    ALAssetsLibrary *lib = [[ALAssetsLibrary alloc] init];
    [lib writeVideoAtPathToSavedPhotosAlbum:mediaURL completionBlock:^(NSURL *assetURL, NSError *error) {
        if (error) {
            NSLog(@"saveAssetLibraryVideo %@", error);
        } else {
            NSLog(@"saveAssetLibraryVideo success");
        }
    }];
}

使用PHPhoto框架保存视频到相册

- (void)savePhotoLibraryVideo:(NSURL *)mediaURL {
    [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
            [PHAssetChangeRequest creationRequestForAssetFromVideoAtFileURL:mediaURL];
        } completionHandler:^(BOOL success, NSError * _Nullable error) {
            if (error) {
                NSLog(@"savePhotoLibraryVideo %@", error);
            } else {
                NSLog(@"savePhotoLibraryVideo success");
            }
        }];
}

权限

需要在Info.plist文件中，添加权限

图片压缩

iOS自带压缩方法UIImageJPEGRepresentation

- (NSData *)compressOriginalImage:(UIImage *)image toMaxDataSizeKBytes:(CGFloat)maxSize {
    NSData * data = UIImageJPEGRepresentation(image, 1.0);
    CGFloat dataKBytes = data.length;
    CGFloat maxQuality = 1.0f;
    while (dataKBytes > maxSize && maxQuality > 0.1f) {
        maxQuality = maxQuality - 0.1f;
        data = UIImageJPEGRepresentation(image, maxQuality);
        dataKBytes = data.length;
    }
    return data;
}