如何允许用户从他的相机胶卷或照片库中挑选照片？

Question

我正在制作一个有趣的照片编辑应用程序。用户必须从他们的相机胶卷中选择一张照片，然后将其导入以进行修改。

这通常是如何工作的？我见过许多应用程序允许使用看起来始终相同的标准控制器。

是否也可以直接访问该库或自定义该控制器的外观？

我应该从哪里开始寻找？

Answer 1

最简单的方法是在简单的 alertView 中使用 UIImagePickerController。

例如，您希望某人点击他们的个人资料照片，并能够从他们的相机或照片库中设置新图像。

@IBAction func btnProfilePicTap(sender: AnyObject) {
    let picker = UIImagePickerController()
    picker.delegate = self
    let alert = UIAlertController(title: nil, message: nil, preferredStyle: .actionSheet)
    alert.addAction(UIAlertAction(title: "Camera", style: .default, handler: {
        action in
        picker.sourceType = .camera
        self.present(picker, animated: true, completion: nil)
    }))
    alert.addAction(UIAlertAction(title: "Photo Library", style: .default, handler: {
        action in
        picker.sourceType = .photoLibrary
        self.present(picker, animated: true, completion: nil)
    }))
    alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
    self.present(alert, animated: true, completion: nil)
}

然后只需添加代理即可。

extension ProfileViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate {
    func imagePickerController(picker: UIImagePickerController, didFinishPickingImage image: UIImage!, editingInfo: [NSObject : AnyObject]!) {
        //use image here!
        dismiss(animated: true, completion: nil)
    }

    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        dismiss(animated: true, completion: nil)
    }
}

对不起，这个例子很快，但我希望它仍然有帮助。

编辑：为 Swift 5 更新。

Answer 2

我开发了一个允许用户选择个人图像的应用程序。我有两个 UIButtons 可以帮助用户选择图片，无论是来自相机还是图书馆。是这样的：

- (void)camera {
if(![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]){
    return;
}
UIImagePickerController *picker = [[[UIImagePickerController alloc] init] autorelease];
picker.sourceType = UIImagePickerControllerSourceTypeCamera;
//Permetto la modifica delle foto
picker.allowsEditing = YES;
//Imposto il delegato
[picker setDelegate:self];

[self presentModalViewController:picker animated:YES];
}
- (void)library {
//Inizializzo la classe per la gestione della libreria immagine
UIImagePickerController *picker = [[[UIImagePickerController alloc] init] autorelease];
picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
//Permetto la modifica delle foto
picker.allowsEditing = YES;
//Imposto il delegato
[picker setDelegate:self];

[self presentModalViewController:picker animated:YES];
}

你必须实现 UIImagePickerControllerDelegate：

@interface PickPictureViewController : UIViewController <UIImagePickerControllerDelegate>

@implementation PickPictureViewController

#pragma mark UIImagePickerController Delegate
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{
UIImage *pickedImage = [info objectForKey:UIImagePickerControllerEditedImage];
if (picker.sourceType == UIImagePickerControllerSourceTypeCamera) {
    UIImageWriteToSavedPhotosAlbum(pickedImage, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
}
[self dismissModalViewControllerAnimated:YES];
}
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{
[self dismissModalViewControllerAnimated:YES];
}
- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo{}

希望对您有所帮助！ ;)

Answer 3

此答案仅适用于物理设备！

访问相机：

- (void)takePhoto {

UIImagePickerController *picker = [[UIImagePickerController alloc] init];
picker.delegate = self;
picker.allowsEditing = YES;
picker.sourceType = UIImagePickerControllerSourceTypeCamera;

[self presentViewController:picker animated:YES completion:NULL];

}

访问相机胶卷：

- (void)selectPhoto {

UIImagePickerController *picker = [[UIImagePickerController alloc] init];
picker.delegate = self;
picker.allowsEditing = YES;
picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

[self presentViewController:picker animated:YES completion:NULL];


}

实现 UIImagePickerController 的委托方法：

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {

UIImage *chosenImage = info[UIImagePickerControllerEditedImage];
self.imageView.image = chosenImage;

[picker dismissViewControllerAnimated:YES completion:NULL];

}

还有这个：

- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker {

[picker dismissViewControllerAnimated:YES completion:NULL];

}

还可以查看link的更多信息

Answer 4

SWIFT 2.0

感谢 William T。这对我的 UITapGestureRecognizer 有用

func selectPhoto(tap: UITapGestureRecognizer) {
    let picker = UIImagePickerController()
    picker.delegate = self
    let alert = UIAlertController(title: nil, message: nil, preferredStyle: .ActionSheet)
    alert.addAction(UIAlertAction(title: "Camera", style: .Default, handler: {
        action in
        picker.sourceType = .Camera
        picker.allowsEditing = true
        self.presentViewController(picker, animated: true, completion: nil)
    }))
    alert.addAction(UIAlertAction(title: "Photo Library", style: .Default, handler: {
        action in
        picker.sourceType = .PhotoLibrary
        picker.allowsEditing = true
        self.presentViewController(picker, animated: true, completion: nil)
    }))
    alert.addAction(UIAlertAction(title: "Cancel", style: .Cancel, handler: nil))
    self.presentViewController(alert, animated: true, completion: nil)
}

我添加了以下内容，以便在将照片同时选择到 .Camera 和 .PhotoLibrary 后对其进行编辑：

picker.allowsEditing = true

Answer 5

看看UIImagePickerController

Answer 6

@WilliamT 的回答对我来说非常有效。这是他的，但已针对 Swift 4 进行了更新，以防有人仍在寻找它。

这将进入包含您要触发相机/图像选择器的按钮的视图控制器类块。

@IBAction func YourButtonToTriggerCamera/ImagePicker(_ sender: UIButton) {
    let picker = UIImagePickerController()
    picker.delegate = (self as UIImagePickerControllerDelegate & UINavigationControllerDelegate)
    let alert = UIAlertController(title: nil, message: nil, preferredStyle: .actionSheet)
    alert.addAction(UIAlertAction(title: "Camera", style: .default, handler: {
        action in
        picker.sourceType = .camera
        self.present(picker, animated: true, completion: nil)
    }))
    alert.addAction(UIAlertAction(title: "Photo Library", style: .default, handler: {
        action in
        picker.sourceType = .photoLibrary
        self.present(picker, animated: true, completion: nil)
    }))
    alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
    self.present(alert, animated: true, completion: nil)
}

这在你的视图控制器类下面：

extension YourViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate {

    func imagePickerController(picker: UIImagePickerController, didFinishPickingImage image: UIImage!, editingInfo: [NSObject : AnyObject]!) {
        //use image here!
        dismiss(animated: true, completion: nil)
    }

    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        dismiss(animated: true, completion: nil)
    }
}

Answer 7

这是一个示例应用程序和一个包装器，可以像 Facebook 一样为您提供拍照或从库中选择。 https://github.com/fulldecent/FDTake