在中级篇里面，已经介绍过相册与拍照的简单使用了，那么接下来我们就来讲一讲它们的后续处理，到底应该怎么做才好呢

首先我们先来讲拍照

还是那个点击使用照片后调用的代理方法中，我们来做以下代码中所提到的事情

- (void)p_w_picpathPickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {[picker dismissViewControllerAnimated:YES completion:NULL];NSString *mediaType = [info valueForKey:UIImagePickerControllerMediaType];UIImage *newImage;WS(weakSelf);if ([mediaType isEqualToString:@"public.p_w_picpath"]) {UIImage *originImage = [info objectForKey:UIImagePickerControllerOriginalImage];dispatch_sync(dispatch_get_global_queue(0, 0), ^{[weakSelf saveImageToPhotos:originImage];});newImage = [self scaleImage:originImage toScale:0.1];}[_p_w_picpathArray addObject:newImage];
}

这个时候，从里面取出的图片是原图，毕竟尺寸、占用内存都比较大，我们需要进行剪切来优化它

-(UIImage *)scaleImage:(UIImage *)p_w_picpath toScale:(float)scaleSize {UIGraphicsBeginImageContext(CGSizeMake(p_w_picpath.size.width*scaleSize,p_w_picpath.size.height*scaleSize));[p_w_picpath drawInRect:CGRectMake(0, 0, p_w_picpath.size.width * scaleSize, p_w_picpath.size.height *scaleSize)];UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();UIGraphicsEndImageContext();return scaledImage;
}

当然了，原图我们也是需要保存到相册里面的，所以我们的保存方法如下

- (void)saveImageToPhotos:(UIImage *)savedImage {UIImageWriteToSavedPhotosAlbum(savedImage, self, @selector(p_w_picpath:didFinishSavingWithError:contextInfo:), nil);
}- (void)p_w_picpath:(UIImage *)p_w_picpath didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {NSString *message = nil;if (error) {message = @"保存失败";} else {message = @"保存成功";[self getAssetsLastPhoto];}NSLog(@"%@", message);
}

这就是拍照后续的使用了，如果还需要优化的话，那就要看你们的产品以及后台如何制定方案了

接下来我们来讲一讲相册吧

最常用的就是我们需要调用一个方法，将所有的照片都取出来，这里要注意的一点是，我们只要缩略图以及原图URL地址就可以了，因为它们两个还是比较重要的

- (void)loadAssets {// Initialise_assets = [NSMutableArray new];_assetLibrary = [[ALAssetsLibrary alloc] init];// Run in the background as it takes a while to get all assets from the librarydispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{NSMutableArray *assetGroups = [[NSMutableArray alloc] init];NSMutableArray *assetURLDictionaries = [[NSMutableArray alloc] init];// Process assetsvoid (^assetEnumerator)(ALAsset *, NSUInteger, BOOL *) = ^(ALAsset *result, NSUInteger index, BOOL *stop) {if (result != nil) {if ([[result valueForProperty:ALAssetPropertyType] isEqualToString:ALAssetTypePhoto]) {[assetURLDictionaries addObject:[result valueForProperty:ALAssetPropertyURLs]];NSURL *url = result.defaultRepresentation.url;[_assetLibrary assetForURL:urlresultBlock:^(ALAsset *asset) {if (asset) {@synchronized(_assets) {[_assets addObject:asset];if (_assets.count == 1) {// Added first asset so reload data//                                                   [self.tableView performSelectorOnMainThread:@selector(reloadData) withObject:nil waitUntilDone:NO];}}}}failureBlock:^(NSError *error){NSLog(@"operation was not successfull!");}];}}};// Process groupsvoid (^ assetGroupEnumerator) (ALAssetsGroup *, BOOL *) = ^(ALAssetsGroup *group, BOOL *stop) {if (group != nil) {[group enumerateAssetsWithOptions:NSEnumerationReverse usingBlock:assetEnumerator];[assetGroups addObject:group];}};// Process![self.assetLibrary enumerateGroupsWithTypes:ALAssetsGroupAllusingBlock:assetGroupEnumeratorfailureBlock:^(NSError *error) {NSLog(@"There is an error");}];});}

在显示缩略图的地方，我们可以显示缩略图，而在显示原图的地方，我们也可以根据URL显示原图

@synchronized(_assets) {NSMutableArray *copy = [_assets copy];for (ALAsset *asset in copy) {[photos addObject:[MWPhoto photoWithThumbImage:[UIImage p_w_picpathWithCGImage:asset.thumbnail]  URL:asset.defaultRepresentation.url]];}}

上面的方法，就是加入原图的缩略图以及地址URL，这里我用了一个包含两个属性的类来添加，当然你也可以弄两个类来单独添加

另外在上传图片的时候还是需要对原图进行剪切，改变base64，当然还是要看你们服务器那边的方案

好啦，这就是我们对相册以及拍照的后处理咯

就写到这里吧，有什么问题，可以来群里找我哦