无法从 UIKit.UIImage 转换为 ZXing.LuminanceSource - Visual Studios 2017 中的 Xamarin iOS

Question

我看到的所有示例都是针对 Xamarin Forms 的，没有针对 Xamarin for Visual Studios 的。我有一个 iOS 应用程序正在使用 Xamarin 为 Visual Studio 开发并且需要读取条形码。我从 NuGet 下载 ZBar 到 Visual Studio 2017 并安装它，没问题。我访问相机并捕获图像（条形码），没问题。但是，似乎没有办法将从相机捕获的 UIKit.UIIMage 转换为 "ZXing.LuminanceSource" 以便对其进行解码。如果有人能帮助我指出正确的方向，我将不胜感激。我的代码相当简单，取自下载中包含的 ZBar 示例：

IBarcodeReader scanPage = new BarcodeReader();

var result = scanPage.Decode(theImage); // the image is public and is set to the image returned by the camera.  It's here I get the error in intellisense "cannot convert from UIKit.UIImage to ZXing.LuminanceSource"

相机图片return代码：

    [Foundation.Export("imagePickerController:didFinishPickingImage:editingInfo:")]
    public void FinishedPickingImage(UIKit.UIImagePickerController picker, UIKit.UIImage image, Foundation.NSDictionary editingInfo)
    {
        theImage = MaxResizeImage(image, 540f, 960f);
        picker.DismissModalViewController(false);

    }

    [Foundation.Export("imagePickerControllerDidCancel:")]
    public void Canceled(UIKit.UIImagePickerController picker)
    {
        DismissViewController(true, null);
    }

    public static UIImage MaxResizeImage(UIImage sourceImage, float maxWidth, float maxHeight)
    {
        var sourceSize = sourceImage.Size;
        var maxResizeFactor = Math.Min(maxWidth / sourceSize.Width, maxHeight / sourceSize.Height);
        if (maxResizeFactor > 1) return sourceImage;
        var width = maxResizeFactor * sourceSize.Width;
        var height = maxResizeFactor * sourceSize.Height;
        UIGraphics.BeginImageContext(new CGSize((nfloat)width, (nfloat)height));
        sourceImage.Draw(new CGRect(0, 0, (nfloat)width, (nfloat)height));
        var resultImage = UIGraphics.GetImageFromCurrentImageContext();
        UIGraphics.EndImageContext();
        return resultImage;
    }

}

Answer 1

我在@Jason 的帮助下设法解决了这个问题，谢谢 Jason。我从 NuGet 下载并安装了 ZXing.Net.Mobile AND ZXing.Net.Mobile.Forms。对于 Xamarin - Visual Studios，你需要两者。删除了所有相机代码并替换为 3 行代码，另外我需要将 async 添加到我的 button_TouchUpInside 调用中。

在 AppDelegate FinishedLaunching 中：

    public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)
    {
        // Override point for customization after application launch.
        // If not required for your application you can safely delete this method

        // Add this line to initialize ZXing

        ZXing.Net.Mobile.Forms.iOS.Platform.Init();

        return true;
    }

按钮代码改成这样，按钮async变成await扫描结果：

    async partial void ScanBarCode_TouchUpInside(UIButton sender)
    {
       // Create scanner
        var scanner = new ZXing.Mobile.MobileBarcodeScanner();

        // Store result of scan in var result, need to await scan
        var result = await scanner.Scan();

        // display bar code number in text field
        Textbox_BarCode.Text = result.Text;
    }

每次都有效（到目前为止）。

无法从 UIKit.UIImage 转换为 ZXing.LuminanceSource - Visual Studios 2017 中的 Xamarin iOS

cannot convert from UIKit.UIImage to ZXing.LuminanceSource - Xamarin iOS in Visual Studios 2017

xamarin.ios

zxing

xamarin

zbar

visual-studio-2017