ios之 本地音视频的获取

  插播一段iOS的知识点 证明我也是一个iOS工程师

1、检索音视频

[objc] view plain copy print ?

1. PHFetchOptions *allPhotosOptions;  
2. @property (nonatomic, strong) PHFetchResult *assetsFetchResults;  
3. if (allPhotosOptions == nil) {  
4.           
5.         allPhotosOptions = [[PHFetchOptions alloc] init];  
6.         allPhotosOptions.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:YES]];  
7.     }  
8.  self.assetsFetchResults = [PHAsset fetchAssetsWithMediaType:PHAssetMediaTypeImage options:allPhotosOptions];  

PHFetchOptions *allPhotosOptions;
@property (nonatomic, strong) PHFetchResult *assetsFetchResults;
if (allPhotosOptions == nil) {
        
        allPhotosOptions = [[PHFetchOptions alloc] init];
        allPhotosOptions.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:YES]];
    }
 self.assetsFetchResults = [PHAsset fetchAssetsWithMediaType:PHAssetMediaTypeImage options:allPhotosOptions];

其中assetsFetchResults存储了所有的图片信息，PHAssetMediaTypeImage为搜索图片的类型，同样的搜索其他类的可以根据

[objc] view plain copy print ?

1. <span style="font-size: 18px;">typedef NS_ENUM(NSInteger, PHAssetMediaType) {  
2.     PHAssetMediaTypeUnknown = 0,  
3.     PHAssetMediaTypeImage   = 1,  
4.     PHAssetMediaTypeVideo   = 2,  
5.     PHAssetMediaTypeAudio   = 3,  
6. } NS_ENUM_AVAILABLE_IOS(8_0);</span>  

<span style="font-size: 18px;">typedef NS_ENUM(NSInteger, PHAssetMediaType) {
    PHAssetMediaTypeUnknown = 0,
    PHAssetMediaTypeImage   = 1,
    PHAssetMediaTypeVideo   = 2,
    PHAssetMediaTypeAudio   = 3,
} NS_ENUM_AVAILABLE_IOS(8_0);</span>

2、获取图片UIImage

[objc] view plain copy print ?

1. <span style="font-size: 18px;">[[PHCachingImageManager defaultManager] requestImageForAsset:asset  
2.                                     targetSize:AssetGridThumbnailSize  
3.                                    contentMode:PHImageContentModeAspectFill  
4.                                        options:nil  
5.                                  resultHandler:^(UIImage *result, NSDictionary *info) {  
6.                                      // Set the cell's thumbnail image if it's still showing the same asset.  
7.                                      if ([cell.representedAssetIdentifier isEqualToString:asset.localIdentifier]) {  
8.                                          cell.thumbnailImage = result;  
9.                                      }  
10.                                  }];  
11. </span>  

<span style="font-size: 18px;">[[PHCachingImageManager defaultManager] requestImageForAsset:asset
                                    targetSize:AssetGridThumbnailSize
                                   contentMode:PHImageContentModeAspectFill
                                       options:nil
                                 resultHandler:^(UIImage *result, NSDictionary *info) {
                                     // Set the cell's thumbnail image if it's still showing the same asset.
                                     if ([cell.representedAssetIdentifier isEqualToString:asset.localIdentifier]) {
                                         cell.thumbnailImage = result;
                                     }
                                 }];
</span>

asset为assetsFetchResults中的一个PHAsset，targetSize是获取图片的大小，这个根据你显示的方式设置，如果需要获取图片其他信息比如标题可以采用

[objc] view plain copy print ?

1. [phAsset valueForKey:@"filename"];  

[phAsset valueForKey:@"filename"];

3、播放视频

[objc] view plain copy print ?

1. -(void)setVideoAsset:(PHAsset *)videoAsset  
2. {  
3.     _videoAsset = videoAsset;  
4.     [[PHImageManager defaultManager] requestPlayerItemForVideo:_videoAsset options:nil resultHandler:^(AVPlayerItem * _Nullable playerItem, NSDictionary * _Nullable info) {  
5.         self.currentItem = playerItem;  
6.         [self.player replaceCurrentItemWithPlayerItem:self.currentItem];  
7.         [self.currentItem addObserver:self forKeyPath:@"status" options:NSKeyValueObservingOptionNew context:nil];  
8.     }];  
9. }  

-(void)setVideoAsset:(PHAsset *)videoAsset
{
    _videoAsset = videoAsset;
    [[PHImageManager defaultManager] requestPlayerItemForVideo:_videoAsset options:nil resultHandler:^(AVPlayerItem * _Nullable playerItem, NSDictionary * _Nullable info) {
        self.currentItem = playerItem;
        [self.player replaceCurrentItemWithPlayerItem:self.currentItem];
        [self.currentItem addObserver:self forKeyPath:@"status" options:NSKeyValueObservingOptionNew context:nil];
    }];
}