Xamarin形式PCL的ZXing QR代码生成 [英] ZXing QR Code Generation in Xamarin Forms PCL

问题描述

我正在尝试使用ZXing软件包生成和显示QR代码，但是我尝试了以下代码，但我无法显示QR代码.它显示空白图像(透明).

I'm trying to generate and display QR code using ZXing package, I tried in following code I was not able to show QR code. It's showing blank image (transparent).

private void OnGenerateQRCodeButton_Clicked(object sender, EventArgs e)
    {

        var writer = new BarcodeWriter
        {
            Format = BarcodeFormat.QR_CODE,
            Options = new EncodingOptions
            {
                Height = (int)imageCompanyLogo.Height,
                Width = (int) imageCompanyLogo.Width,
                Margin = 0,
                PureBarcode = true
            }
        };
        var bitmap = writer.Write("www.helloworld.com");
        imageQRCode.Source = ImageSource.FromStream(() => new MemoryStream(bitmap));
    }

请提出任何建议.谢谢.

Please suggest any way to do it. Thanks.

推荐答案

1. 在PCL(Xamarin)项目中为依赖服务创建接口.
2. 在Native(Xamarin.Droid)中创建一个类，并从PCL接口继承.

3. 实施如下所示的方法.

1. Create interface in PCL(Xamarin) project for Dependency Service.
2. Create a class in Native(Xamarin.Droid) and Inherit from PCL Interface.

3. Implement the method as shown below.

public Stream ConvertImageStream(string text, int width = 300, int height = 300)
{
    var barcodeWriter = new ZXing.Mobile.BarcodeWriter
    {
        Format = ZXing.BarcodeFormat.QR_CODE,
        Options = new ZXing.Common.EncodingOptions
        {
            Width = width,
            Height = height,
            Margin = 10
        }
    };

    barcodeWriter.Renderer = new ZXing.Mobile.BitmapRenderer();
    var bitmap = barcodeWriter.Write(text);
    var stream = new MemoryStream();
    bitmap.Compress(Bitmap.CompressFormat.Png, 100, stream);  // this is the diff between iOS and Android
    stream.Position = 0;
    return stream;
}

使用Dependency Service从PCL(Xamarin)项目中调用该方法.

在xaml.cs中

call the method from PCL(Xamarin) project using Dependency Service.

In xaml.cs

private void OnGenerateQRCodeButton_Clicked(object sender, EventArgs e)
{
    string barcodeText = "www.helloworld.com";
    var stream = DependencyService.Get<IBarCodeServices>().ConvertImageStream(barcodeText, (int)imageCompanyLogo.Width,(int) imageCompanyLogo.Height);
    barcodeImage.Source = ImageSource.FromStream(() => stream);
}

这篇关于Xamarin形式PCL的ZXing QR代码生成的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！