iOS截屏(视频黑色)并保存到自定义相册

1.截屏

用方法1正常,用方法2视频黑色.
当然你要确定view是不是最底层的view.
区别查到再补充,先做个记录

- (UIImage *)captureCurrentView:(UIView *)view {
    
    方法1:(iOS7后替换方法2了)
UIGraphicsBeginImageContextWithOptions(view.frame.size, NO, 0.0);
    
    [view drawViewHierarchyInRect:view.frame afterScreenUpdates:YES];
    
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    
    UIGraphicsEndImageContext();
    return image;


    方法2:
    //    // 创建一个context
    //    UIGraphicsBeginImageContextWithOptions(view.bounds.size, NO, 0.0);
    //
    //    //把当前的全部画面导入到栈顶context中并进行渲染
    //    [view.layer renderInContext:UIGraphicsGetCurrentContext()];
    //
    //    // 从当前context中创建一个新图片
    //    UIImage * img = UIGraphicsGetImageFromCurrentImageContext();
    //
    //    // 使当前的context出堆栈
    //    UIGraphicsEndImageContext();

    //    return img;
}

2.保存到自定义相册

导入photos框架

#pragma mark - 截图
- (void)screenshot{
    DLog(@"jietu");
    UIImage *image = [self captureCurrentView:self.view];
    [self saveImageToPhotos:image];
}

#pragma mark - 保存图片
- (void)saveImageToPhotos:(UIImage *)image {
    //权限判断
    PHAuthorizationStatus status = [PHPhotoLibrary authorizationStatus];
    if (status == PHAuthorizationStatusDenied || status == PHAuthorizationStatusRestricted) {
        [QYprogressHUD showInfoWithStatus:@"未开启相册权限,请在系统设置中开启"];
        return;
    }else{
        PHFetchResult *assets = [self syncSaveImageWithPhotos:image];//同步保存图片
        if (assets == nil) {
            [QYprogressHUD showErrorWithStatus:@"保存失败"];
            return;
        }
        
        PHAssetCollection * Album = [self creatAlbum];//创建相册
        if (Album == nil) {
            [QYprogressHUD showErrorWithStatus:@"创建相册失败"];
            return;
        }
        
        NSError *error = nil;
        [[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
            //--告诉系统，要操作哪个相册
            PHAssetCollectionChangeRequest *collectionChangeRequest = [PHAssetCollectionChangeRequest changeRequestForAssetCollection:Album];
            //--添加图片到自定义相册--追加--就不能成为封面了
            //--[collectionChangeRequest addAssets:assets];
            //--插入图片到自定义相册--插入--可以成为封面
            [collectionChangeRequest insertAssets:assets atIndexes:[NSIndexSet indexSetWithIndex:0]];
        } error:&error];
        if (error) {
            [QYprogressHUD showErrorWithStatus:@"保存失败"];
            
        }else
            [QYprogressHUD showSuccessWithStatus:@"保存成功"];
    }
    

//    UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:),nil);//保存到系统相册
}
/**同步方式保存图片到系统的相机胶卷中---返回的是当前保存成功后相册图片对象集合*/
-(PHFetchResult *)syncSaveImageWithPhotos:(UIImage *)image
{
    //--1 创建 ID 这个参数可以获取到图片保存后的 asset对象
    __block NSString *createdAssetID = nil;
    
    //--2 保存图片
    NSError *error = nil;
    [[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
        //----block 执行的时候还没有保存成功--获取占位图片的 id，通过 id 获取图片---同步
        createdAssetID = [PHAssetChangeRequest             creationRequestForAssetFromImage:image].placeholderForCreatedAsset.localIdentifier;
    } error:&error];
    
    //--3 如果失败，则返回空
    if (error) {
        return nil;
    }
    
    //--4 成功后，返回对象
    //获取保存到系统相册成功后的 asset 对象集合，并返回
    PHFetchResult *assets = [PHAsset fetchAssetsWithLocalIdentifiers:@[createdAssetID] options:nil];
    return assets;
    
}
- (PHAssetCollection *)creatAlbum{
    NSString *title = [NSBundle mainBundle].infoDictionary[(__bridge NSString *)kCFBundleNameKey];
    //2 获取与 APP 同名的自定义相册
    PHFetchResult *collections = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];
    for (PHAssetCollection *collection in collections) {
        //遍历
        if ([collection.localizedTitle isEqualToString:title]) {
            //找到了同名的自定义相册--返回
            return collection;
        }
    }
    
    //说明没有找到，需要创建
    NSError *error = nil;
    __block NSString *createID = nil; //用来获取创建好的相册
    [[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
        //发起了创建新相册的请求，并拿到ID，当前并没有创建成功，待创建成功后，通过 ID 来获取创建好的自定义相册
        PHAssetCollectionChangeRequest *request = [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:title];
        createID = request.placeholderForCreatedAssetCollection.localIdentifier;
    } error:&error];
    if (error) {
        [QYprogressHUD showErrorWithStatus:@"创建失败"];
        return nil;
    }else{
        [QYprogressHUD showSuccessWithStatus:@"创建成功"];
        //通过 ID 获取创建完成的相册 -- 是一个数组
        return [PHAssetCollection fetchAssetCollectionsWithLocalIdentifiers:@[createID] options:nil].firstObject;
    }
}

权限
PHAuthorizationStatusNotDetermined ,---用户之前还未决定
PHAuthorizationStatusRestricted, ---系统问题，用户没有权限决定--比如家长控制器模式
PHAuthorizationStatusDenied,---用户之前拒绝过
PHAuthorizationStatusAuthorized --用户允许

这部分参考了http://www.jianshu.com/p/43ae2a98147f ,我谢谢你

3.保存到系统相册

//    UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:),nil);//保存到系统相册
//-  (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {
//    if (error == nil) {
//        NSLog(@"保存成功");
//        [QYprogressHUD showSuccessWithStatus:@"截图以保存到相册"];
//    } else {
//        NSLog(@"失败");
//        [QYprogressHUD showErrorWithStatus:@"截图失败"];
//    }
//}

4.知识点补充

4.1首次判断相册权限

PHAuthorizationStatus status = [PHPhotoLibrary authorizationStatus];
    if (status == PHAuthorizationStatusNotDetermined) {
        [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
            if (status == PHAuthorizationStatusAuthorized) {//同意
                [weakSelf canSaveImg:image];
                return ;

            }else
            {
                [QYprogressHUD showInfoWithStatus:@"未获得相册权限,截屏保存失败"];
                return ;
            } 
        }];
    }

待续...