保存到自定义相册分3步:
-
1.添加图片到【相机胶卷】
1> UIImageWriteToSavedPhotosAlbum函数
2> AssetsLibrary框架(已过期,一般不用了)
3> Photos框架(推荐) -
2.拥有一个【自定义相册】
1> AssetsLibrary框架
2> Photos框架(推荐) -
3.将刚才添加到【相机胶卷】的图片，引用（添加）到【自定义相册】
1> AssetsLibrary框架
2> Photos框架(推荐)
Photos框架
-
Photos框架须知
-
1.PHAsset : 一个PHAsset对象代表一张图片或者一个视频文件
1> 负责查询一堆的PHAsset对象 -
2.PHAssetCollection : 一个PHAssetCollection对象代表一个相册
1> 负责查询一堆的PHAssetCollection对象 -
3.PHAssetChangeRequest
1> 负责执行对PHAsset(照片或视频)的【增删改】操作
2> 这个类只能放在-[PHPhotoLibrary performChanges:completionHandler:] 或者 -[PHPhotoLibrary performChangesAndWait:error:]方法的block中使用 -
4.PHAssetCollectionChangeRequest
1> 负责执行对PHAssetCollection(相册)的【增删改】操作
2> 这个类只能放在-[PHPhotoLibrary performChanges:completionHandler:] 或者 -[PHPhotoLibrary performChangesAndWait:error:]方法的block中使用 -
iOS中的 ~增删改查CRUD
一:保存图片到相册
错误信息
This method can only be called from inside of -[PHPhotoLibrary performChanges:completionHandler:] or -[PHPhotoLibrary performChangesAndWait:error:]
解决防范
// Asynchronously 异步执行操作
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
[PHAssetChangeRequest creationRequestForAssetFromImage:self.imageView.image];
} completionHandler:^(BOOL success, NSError * _Nullable error) {
XMGLog(@"保存完毕")
}];
// Synchronously 同步执行操作
NSError *error = nil;
[[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
[PHAssetChangeRequest creationRequestForAssetFromImage:self.imageView.image];
} error:&error];
demo
- (IBAction)save {
__block NSString *createdAssetId = nil;
// 添加图片到【相机胶卷】
// 同步方法,直接创建图片,代码执行完,图片没创建完,所以使用占位ID (createdAssetId)
[[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
createdAssetId = [PHAssetChangeRequest creationRequestForAssetFromImage:self.imageView.image].placeholderForCreatedAsset.localIdentifier;
} error:nil];
// 在保存完毕后取出图片
PHFetchResult<PHAsset *> *createdAssets = [PHAsset fetchAssetsWithLocalIdentifiers:@[createdAssetId] options:nil];
// 获取软件的名字作为相册的标题
//如果用普通plist文件创建方法创建是错误的,如
//[NSDictionary dictionaryWithContensOfFile:[[NSBundle mainBundle] pathForResource:@"Test"ofType:@"plist"]];
// 系统的plist文件只能使用以下方法调用
NSString *title = [NSBundle mainBundle].infoDictionary[(NSString *)kCFBundleNameKey];
// 已经创建的自定义相册
PHAssetCollection *createdCollection = nil;
// 获得所有的自定义相册
PHFetchResult<PHAssetCollection *> *collections = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];
for (PHAssetCollection *collection in collections) {
if ([collection.localizedTitle isEqualToString:title]) {
createdCollection = collection;
break;
}
}
if (!createdCollection) { // 没有创建过相册
__block NSString *createdCollectionId = nil;
// 创建一个新的相册
[[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
createdCollectionId = [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:title].placeholderForCreatedAssetCollection.localIdentifier;
} error:nil];
// 创建完毕后再取出相册
createdCollection = [PHAssetCollection fetchAssetCollectionsWithLocalIdentifiers:@[createdCollectionId] options:nil].firstObject;
}
if (createdAssets == nil || createdCollection == nil) {
[SVProgressHUD showErrorWithStatus:@"保存失败！"];
return;
}
// 将刚才添加到【相机胶卷】的图片，引用（添加）到【自定义相册】
NSError *error = nil;
[[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
PHAssetCollectionChangeRequest *request = [PHAssetCollectionChangeRequest changeRequestForAssetCollection:createdCollection];
// 自定义相册封面默认保存第一张图,所以使用以下方法把最新保存照片设为封面
[request insertAssets:createdAssets atIndexes:[NSIndexSet indexSetWithIndex:0]];
} error:&error];
// 保存结果
if (error) {
[SVProgressHUD showErrorWithStatus:@"保存失败！"];
} else {
[SVProgressHUD showSuccessWithStatus:@"保存成功！"];
}
}
封装与授权
/**
* 获得刚才添加到【相机胶卷】中的图片
*/
- (PHFetchResult<PHAsset *> *)createdAssets
{
__block NSString *createdAssetId = nil;
// 添加图片到【相机胶卷】
[[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
createdAssetId = [PHAssetChangeRequest creationRequestForAssetFromImage:self.imageView.image].placeholderForCreatedAsset.localIdentifier;
} error:nil];
if (createdAssetId == nil) return nil;
// 在保存完毕后取出图片
return [PHAsset fetchAssetsWithLocalIdentifiers:@[createdAssetId] options:nil];
}
/**
* 获得【自定义相册】
*/
- (PHAssetCollection *)createdCollection
{
// 获取软件的名字作为相册的标题
NSString *title = [NSBundle mainBundle].infoDictionary[(NSString *)kCFBundleNameKey];
// 获得所有的自定义相册
PHFetchResult<PHAssetCollection *> *collections = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];
for (PHAssetCollection *collection in collections) {
if ([collection.localizedTitle isEqualToString:title]) {
return collection;
}
}
// 代码执行到这里，说明还没有自定义相册
__block NSString *createdCollectionId = nil;
// 创建一个新的相册
[[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
createdCollectionId = [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:title].placeholderForCreatedAssetCollection.localIdentifier;
} error:nil];
if (createdCollectionId == nil) return nil;
// 创建完毕后再取出相册
return [PHAssetCollection fetchAssetCollectionsWithLocalIdentifiers:@[createdCollectionId] options:nil].firstObject;
}
/**
* 保存图片到相册
*/
- (void)saveImageIntoAlbum
{
// 获得相片
PHFetchResult<PHAsset *> *createdAssets = self.createdAssets;
// 获得相册
PHAssetCollection *createdCollection = self.createdCollection;
if (createdAssets == nil || createdCollection == nil) {
[SVProgressHUD showErrorWithStatus:@"保存失败！"];
return;
}
// 将相片添加到相册
NSError *error = nil;
[[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
PHAssetCollectionChangeRequest *request = [PHAssetCollectionChangeRequest changeRequestForAssetCollection:createdCollection];
[request insertAssets:createdAssets atIndexes:[NSIndexSet indexSetWithIndex:0]];
} error:&error];
// 保存结果
if (error) {
[SVProgressHUD showErrorWithStatus:@"保存失败！"];
} else {
[SVProgressHUD showSuccessWithStatus:@"保存成功！"];
}
}
- (IBAction)save {
/*
requestAuthorization方法的功能
1.如果用户还没有做过选择，这个方法就会弹框让用户做出选择
1> 用户做出选择以后才会回调block
2.如果用户之前已经做过选择，这个方法就不会再弹框，直接回调block，传递现在的授权状态给block
*/
PHAuthorizationStatus oldStatus = [PHPhotoLibrary authorizationStatus];
[PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
//涉及到UI弹框 GCD到主线程
dispatch_async(dispatch_get_main_queue(), ^{
switch (status) {
case PHAuthorizationStatusAuthorized: {
// 保存图片到相册
[self saveImageIntoAlbum];
break;
}
case PHAuthorizationStatusDenied: {
if (oldStatus == PHAuthorizationStatusNotDetermined) return;
XMGLog(@"提醒用户打开相册的访问开关")
break;
}
case PHAuthorizationStatusRestricted: {
[SVProgressHUD showErrorWithStatus:@"因系统原因，无法访问相册！"];
break;
}
default:
break;
}
});
}];
// PHAuthorizationStatusNotDetermined
// 用户还没有对当前App授权过(用户从未点击过Don't Allow或者OK按钮)
// PHAuthorizationStatusRestricted
// 因为一些系统原因导致无法访问相册（比如家长控制）
// PHAuthorizationStatusDenied
// 用户已经明显拒绝过当前App访问相片数据（用户已经点击过Don't Allow按钮）
// PHAuthorizationStatusAuthorized
// 用户已经允许过当前App访问相片数据（用户已经点击过OK按钮）
// switch ([PHPhotoLibrary authorizationStatus]) {
// case PHAuthorizationStatusAuthorized: {
// [self saveImageIntoAlbum];
// break;
// }
//
// case PHAuthorizationStatusDenied: {
// // 提醒用户打开访问开关
// break;
// }
//
// case PHAuthorizationStatusRestricted: {
// [SVProgressHUD showErrorWithStatus:@"因系统原因，无法访问相册！"];
// break;
// }
//
// case PHAuthorizationStatusNotDetermined: {
// // 弹框让用户做出选择
// [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
// // 用户刚才点击的是OK按钮
// if (status == PHAuthorizationStatusAuthorized) {
// [self saveImageIntoAlbum];
// }
// }];
// break;
// }
// }
}
/*
PHPhotoLibrary的performChangesAndWait的block不能嵌套，比如下面的写法是错误的
[[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
[[PHPhotoLibrary sharedPhotoLibrary] performChangesAndWait:^{
} error:nil];
} error:nil];
*/
@end
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