如何从 iOS 照片库中获取图像并在 UIWebView 中显示

Posted 2023-03-11

【中文标题】如何从 iOS 照片库中获取图像并在 UIWebView 中显示

【英文标题】：How do I get an image from the iOS photo library and display it in UIWebView

【发布时间】：2013-12-15 13:47:21

【问题描述】：

我见过很多使用UIImage 输出图像的示例。我希望将输出设置为 UIWebView，因为我想在图像周围添加一些额外的 html 格式。

我想让照片库返回存储在 ios 设备上的图像的相对路径，以便我可以将它放在“img”HTML 标记的“src”属性中。

这可能吗？

---

编辑 1

我不得不根据我的需要修改我的代码，但这似乎不起作用。

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

    //Get Image URL from Library
    NSURL *urlPath = [info valueForKey:UIImagePickerControllerReferenceURL];
    NSString *urlString = [urlPath absoluteString];
    NSLog(urlString);

    NSURL *root = [[NSBundle mainBundle] bundleURL];
    NSString *html;
    html = @"<img src='";
    html = [html stringByAppendingString:urlString];
    html = [html stringByAppendingString:@"' />"];
    [MemeCanvas loadHTMLString:html baseURL:root];

    [picker dismissViewControllerAnimated:YES completion:^];

我能够记录资产库 URL，但它似乎没有显示在 UIWebView 上的图像。我不知道我需要将 baseURL 更改为什么。

任何帮助表示赞赏。

---

编辑 2

我将UIImagePickerControllerReferenceURL 更改为UIImagePickerControllerMediaURL，现在它崩溃了，因为当我将它附加到带有stringByAppendingString:urlString 的字符串时它不喜欢它

它给了我错误：

由于未捕获的异常而终止应用程序 'NSInvalidArgumentException'，原因：'*** -[__NSCFConstantString stringByAppendingString:]: 无参数'

你知道是什么原因造成的吗？

【问题讨论】：

如果您只是在图像周围布局一些字符串内容，如何使用 TextKit。感谢@rokjarc 分享了一个好问题。

您需要文件 URL，而不是资产库 URL。将UIImagePickerControllerReferenceURL 更改为UIImagePickerControllerMediaURL。

【参考方案1】：

[更新到 swift 4] 您可以使用UIImagePickerControllerdelegate 选择您要编辑的图片（或网址）。

你可以这样做：

let pickerController = UIImagePickerController()
pickerController.sourceType = .photoLibrary
pickerController.delegate = self
self.navigationController?.present(pickerController, animated: true, completion: 
)

在委托实现中，您可以使用图像的路径或图像本身：

// This method is called when an image has been chosen from the library or taken from the camera.

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any])     
   //You can retrieve the actual UIImage
   let image = info[UIImagePickerControllerOriginalImage] as? UIImage
   //Or you can get the image url from AssetsLibrary
   let path = info[UIImagePickerControllerReferenceURL] as? URL
   picker.dismiss(animated: true, completion: nil)

【讨论】：

如果我使用相机拍摄照片然后[info valueForKey:UIImagePickerControllerReferenceURL]; 给我（空）价值.. 任何解决方案？

【参考方案2】：

斯威夫特 4

class ViewController: UIViewController 
    var pickedImage:UIImage?

    @IBAction func ActionChooseImage(sender:UIButton)
        let imagePickerController = UIImagePickerController()
        imagePickerController.sourceType = .photoLibrary
        imagePickerController.delegate = self
        self.present(imagePickerController, animated: true, completion: nil)
    


extension ViewController: UIImagePickerControllerDelegate,UINavigationControllerDelegate 
    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) 
        let image = info[UIImagePickerControllerOriginalImage] as? UIImage
        self.pickedImage = image

        picker.dismiss(animated: true, completion: nil)
    

Ref

【参考方案3】：

为 Swift 3.0 更新

let imagePickerController = UIImagePickerController()
imagePickerController.sourceType = .PhotoLibrary
imagePickerController.delegate = self
self.presentViewController(imagePickerController, animated: true, completion: nil)

还有代表：

extension YourViewController: UIImagePickerControllerDelegate 
    func imagePickerController(picker: UIImagePickerController, didFinishPickingImage image: UIImage, editingInfo: [String : AnyObject]?) 
        // Whatever you want here
        self.pickedImage = image
        picker.dismissViewControllerAnimated(true, completion: nil)
    

【参考方案4】：

您可以将图片从 Photolibrary 加载到 webview 中，如下代码所示

 - (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info    
       
      NSURL *urlPath = [info valueForKey:UIImagePickerControllerReferenceURL];
      UIImage *cameraImage = [info valueForKey:UIImagePickerControllerOriginalImage];
      NSData *myData = UIImagePNGRepresentation(cameraImage);
      [self.webview loadData:myData MIMEType:@"image/png" textEncodingName:nil baseURL:nil];
      [self.picker dismissViewControllerAnimated:YES completion:nil];
       

【参考方案5】：

请注意，您必须遵守协议UIImagePickerControllerDelegate

UIImagePickerController *myImagePicker = [[UIImagePickerController alloc] init];
        myImagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        myImagePicker.delegate = self;
        [self presentViewController:myImagePicker animated:YES completion:nil];

加载图像，然后在 WebView 中显示。

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

    //Get Image URL from Library
    NSURL *urlPath = [info valueForKey:UIImagePickerControllerReferenceURL];
    NSURLRequest *requestObj = [NSURLRequest requestWithURL:urlPath];
    [webview loadRequest:requestObj];

【讨论】：

这仍然提供资产库 URL，并且您正在删除 OP 想要的所有 HTML。