时间：2021-08-05 08:30:59 | 栏目：iOS代码 | 点击：次
本文介绍了iOS中获取系统相册中的图片，在很多应用中都能用到，可以获取单张图片，也可以同时获取多张图片，废话不多说了，看下面吧。
一.获取单张图片
思路:
1.利用UIImagePickerController可以从系统自带的App(照片\相机)中获得图片
2.设置代理,遵守代理协议
注意这个UIImagePickerController类比较特殊,需要遵守两个代理协议
@interface ViewController () <UIImagePickerControllerDelegate, UINavigationControllerDelegate>
3.实现代理的方法didFinishPickingMediaWithInfo
- (void)getImageFromIpc
{
// 1.判断相册是否可以打开
if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) return;
// 2. 创建图片选择控制器
UIImagePickerController *ipc = [[UIImagePickerController alloc] init];
/**
typedef NS_ENUM(NSInteger, UIImagePickerControllerSourceType) {
UIImagePickerControllerSourceTypePhotoLibrary, // 相册
UIImagePickerControllerSourceTypeCamera, // 用相机拍摄获取
UIImagePickerControllerSourceTypeSavedPhotosAlbum // 相簿
}
*/
// 3. 设置打开照片相册类型(显示所有相簿)
ipc.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
// ipc.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
// 照相机
// ipc.sourceType = UIImagePickerControllerSourceTypeCamera;
// 4.设置代理
ipc.delegate = self;
// 5.modal出这个控制器
[self presentViewController:ipc animated:YES completion:nil];
}
#pragma mark -- <UIImagePickerControllerDelegate>--
// 获取图片后的操作
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info
{
// 销毁控制器
[picker dismissViewControllerAnimated:YES completion:nil];
// 设置图片
self.imageView.image = info[UIImagePickerControllerOriginalImage];
}
二.获取多张图片
思路:
#import <AssetsLibrary/AssetsLibrary.h>
1.获得所有相簿的原图
- (void)getOriginalImages
{
// 获得所有的自定义相簿
PHFetchResult<PHAssetCollection *> *assetCollections = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];
// 遍历所有的自定义相簿
for (PHAssetCollection *assetCollection in assetCollections) {
[self enumerateAssetsInAssetCollection:assetCollection original:YES];
}
// 获得相机胶卷
PHAssetCollection *cameraRoll = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeSmartAlbumUserLibrary options:nil].lastObject;
// 遍历相机胶卷,获取大图
[self enumerateAssetsInAssetCollection:cameraRoll original:YES];
}
2.获得所有相簿中的缩略图
- (void)getThumbnailImages
{
// 获得所有的自定义相簿
PHFetchResult<PHAssetCollection *> *assetCollections = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];
// 遍历所有的自定义相簿
for (PHAssetCollection *assetCollection in assetCollections) {
[self enumerateAssetsInAssetCollection:assetCollection original:NO];
}
// 获得相机胶卷
PHAssetCollection *cameraRoll = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeSmartAlbumUserLibrary options:nil].lastObject;
[self enumerateAssetsInAssetCollection:cameraRoll original:NO];
}
3.遍历相册
/**
* 遍历相簿中的所有图片
* @param assetCollection 相簿
* @param original 是否要原图
*/
- (void)enumerateAssetsInAssetCollection:(PHAssetCollection *)assetCollection original:(BOOL)original
{
NSLog(@"相簿名:%@", assetCollection.localizedTitle);
PHImageRequestOptions *options = [[PHImageRequestOptions alloc] init];
// 同步获得图片, 只会返回1张图片
options.synchronous = YES;
// 获得某个相簿中的所有PHAsset对象
PHFetchResult<PHAsset *> *assets = [PHAsset fetchAssetsInAssetCollection:assetCollection options:nil];
for (PHAsset *asset in assets) {
// 是否要原图
CGSize size = original ? CGSizeMake(asset.pixelWidth, asset.pixelHeight) : CGSizeZero;
// 从asset中获得图片
[[PHImageManager defaultManager] requestImageForAsset:asset targetSize:size contentMode:PHImageContentModeDefault options:options resultHandler:^(UIImage * _Nullable result, NSDictionary * _Nullable info) {
NSLog(@"%@", result);
}];
}
}