你好，

1. 返回的photo是UIImage对象，直接用于显示；asset是PHAsset或者ALAsset对象，用于获取照片的其他所有信息(原图、创建时间、修改时间、经纬度、文件名字、图片类型、图片路径等等信息...)
2. 即使设置了可以选择原图，用户也选择了原图，选择器也不会直接返回你原图，一张原图大小一般2-3M，如果选了多张内存会暴涨，所以返回的photo都是缩略图（适合iPhone尺寸的），要原图需要通过asset去获取。
3. [[TZImageManager manager] getOriginalPhotoWithAsset:completion:] 内部走的是系统方法去获取原图，一般会先返回缩略图，再返回原图。我之前描述不够准确，抱歉，目前已更新描述。

具体什么时候会先返回缩略图，苹果的解释是这样的：

// If the asset's aspect ratio does not match that of the given targetSize, contentMode determines how the image will be resized.
// PHImageContentModeAspectFit: Fit the asked size by maintaining the aspect ratio, the delivered image may not necessarily be the asked targetSize (see PHImageRequestOptionsDeliveryMode and PHImageRequestOptionsResizeMode)
// PHImageContentModeAspectFill: Fill the asked size, some portion of the content may be clipped, the delivered image may not necessarily be the asked targetSize (see PHImageRequestOptionsDeliveryMode && PHImageRequestOptionsResizeMode)
// PHImageContentModeDefault: Use PHImageContentModeDefault when size is PHImageManagerMaximumSize (though no scaling/cropping will be done on the result)
// If -[PHImageRequestOptions isSynchronous] returns NO (or options is nil), resultHandler may be called 1 or more times.
// Typically in this case, resultHandler will be called asynchronously on the main thread with the requested results.
// However, if deliveryMode = PHImageRequestOptionsDeliveryModeOpportunistic, resultHandler may be called synchronously on the calling thread if any image data is immediately available. If the image data returned in this first pass is of insufficient quality, resultHandler will be called again, asychronously on the main thread at a later time with the "correct" results.
// If the request is cancelled, resultHandler may not be called at all.
// If -[PHImageRequestOptions isSynchronous] returns YES, resultHandler will be called exactly once, synchronously and on the calling thread. Synchronous requests cannot be cancelled.
// resultHandler for asynchronous requests, always called on main thread

• (PHImageRequestID)requestImageForAsset:(PHAsset *)asset targetSize:(CGSize)targetSize contentMode:(PHImageContentMode)contentMode options:(nullable PHImageRequestOptions *)options resultHandler:(void (^)(UIImage *__nullable result, NSDictionary *__nullable info))resultHandler;

这个方法能直接拿到图片的路径吗

@raodaye 要路径的话，需要自己保存到沙盒，使用沙盒路径