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
|
1
|
@interface ViewController () <UIImagePickerControllerDelegate, UINavigationControllerDelegate>
|
3.实现代理的方法didFinishPickingMediaWithInfo
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
|
- (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:
- 导入头文件#import <Photos/Photos.h>
- PHAsset : 一个资源, 比如一张图片\一段视频
- PHAssetCollection : 一个相簿
- PHImageManager 图片管理者,是单例,发送请求才能从asset获取图片
- PHImageRequestOptions图片请求选项
- 注意:这个类是iOS8开始推广,iOS9开始废弃之前的方法
- 系统适配iOS8之前,用下面这个库里面的API
|
1
|
#import <AssetsLibrary/AssetsLibrary.h>
|
1.获得所有相簿的原图
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
|
- (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
|
1
2
3
4
5
6
7
8
9
10
11
12
|
- (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
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
|
/**
* 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);
}];
}
}
|
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持服务器之家。