ios oc 文件选择

在iOS Objective-C中，文件选择通常涉及到用户从设备的文件系统中选择文件，这通常发生在需要访问用户相册、文档或其他本地文件的应用场景中。你可以使用`UIImagePickerController`来进行这样的操作。

首先，导入所需框架：

#import <UIKit/UIKit.h>

然后，在需要的视图控制器（UIViewController）中，实现`UIImagePickerControllerDelegate`协议，并设置代理：

@interface YourViewController : UIViewController <UIImagePickerControllerDelegate, UINavigationControllerDelegate>

接着，创建选择图片或文件的方法，比如选择照片：

- (IBAction)selectImage:(id)sender {
    UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];
    imagePickerController.delegate = self;
    imagePickerController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary; // 或者UIImagePickerControllerSourceTypeSavedPhotosAlbum
    [self presentViewController:imagePickerController animated:YES completion:nil];
}

当用户选择完成后，会触发`imagePickerController:didFinishPickingMediaWithInfo:`方法，你可以在其中获取所选文件路径或数据：

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<UIImagePickerControllerInfoKey,id> *)info {
    UIImage *selectedImage = info[UIImagePickerControllerOriginalImage]; // 获取图片
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); // 获取沙盒路径
    NSString *documentsDirectory = paths[0];
    // 将图片保存到指定目录
    NSString *filePath = [documentsDirectory stringByAppendingPathComponent:@"selected_image.jpg"];
    NSData *imageData = UIImagePNGRepresentation(selectedImage);
    [imageData writeToFile:filePath atomically:YES];
    
    [picker dismissViewControllerAnimated:YES completion:nil];
}