DataMatrix 条码格式在 ZXingBarcodeImageView Xamarin Forms Zxing 2.3.2 中模糊 [英] DataMatrix Barcode Format Blurred in ZXingBarcodeImageView Xamarin Forms Zxing 2.3.2

问题描述

我正在尝试在 ZXingBarcodeImageView 中显示 DataMatrix 条码，问题是我使用条码的任何宽度和高度在低分辨率下都很模糊.

I'm trying to display DataMatrix barcode inside ZXingBarcodeImageView, the problem is whatever width and height I use the barcode is blurry with low resolution.

截图

<StackLayout HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand" >
                        <forms1:ZXingBarcodeImageView BarcodeFormat="DATA_MATRIX" BarcodeOptions="{datamatrix:DatamatrixEncodingOptions, Height=100, Width=100}" WidthRequest="100" HeightRequest="100" HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand" BarcodeValue="123456" ></forms1:ZXingBarcodeImageView>

我尝试在 EncodingOptions 和 ZXingBarcodeImageView 本身上设置不同的高度和宽度.

I tried to set different Height and Width in EncodingOptions and on the ZXingBarcodeImageView itself.

有什么推荐吗?

推荐答案

这个 bug 在 ZXing 中仅适用于 DataMatrix，因此我最终只为 Android 和 iOS 创建了自定义渲染器(Windows 工作正常).

This bug is in ZXing portable only for DataMatrix so I ended up by creating custom renderers for Android and iOS only(Windows works fine).

安卓代码:

public class SDataMatrixRenderer : ImageRenderer
{
    public SDataMatrixRenderer(Context context) : base(context)
    {
    }

    protected override void OnElementChanged(ElementChangedEventArgs<Image> e)
    {
        base.OnElementChanged(e);
        if (Element == null)
        {
            return;
        }
        Control.SetImageBitmap(GetBitmap(((SDataMatrix)Element).BitMatrix));
    }


    private Bitmap GetBitmap(BitMatrix bitMatrix)
    {
        int BLACK = Color.Black;
        int WHITE = Color.White;

        // change the values to your needs
        int requestedWidth = 200;
        int requestedHeight = 200;

        int width = bitMatrix.Width;
        int height = bitMatrix.Height;

        // calculating the scaling factor
        int pixelsize = requestedWidth / width;
        if (pixelsize > requestedHeight / height)
        {
            pixelsize = requestedHeight / height;
        }

        int[] pixels = new int[requestedWidth * requestedHeight];
        // All are 0, or black, by default
        for (int y = 0; y < height; y++)
        {
            int offset = y * requestedWidth * pixelsize;

            // scaling pixel height
            for (int pixelsizeHeight = 0; pixelsizeHeight < pixelsize; pixelsizeHeight++, offset += requestedWidth)
            {
                for (int x = 0; x < width; x++)
                {
                    int color = bitMatrix[x, y] ? BLACK : WHITE;

                    // scaling pixel width
                    for (int pixelsizeWidth = 0; pixelsizeWidth < pixelsize; pixelsizeWidth++)
                    {
                        pixels[offset + x * pixelsize + pixelsizeWidth] = color;
                    }
                }
            }
        }
        Bitmap bitmap = Bitmap.CreateBitmap(requestedWidth, requestedHeight, Bitmap.Config.Argb8888);
        bitmap.SetPixels(pixels, 0, requestedWidth, 0, 0, requestedWidth, requestedHeight);

        return bitmap;
    }
}

在 iOS 上:

public class SDataMatrixRenderer : ImageRenderer
{
    protected override void OnElementChanged(ElementChangedEventArgs<Image> e)
    {
        base.OnElementChanged(e);
        if (Element == null)
        {
            return;
        }
        Control.Image = GetImage(((SDataMatrix)Element).BitMatrix);
    }

    public UIImage GetImage(BitMatrix matrix)
    {
        UIGraphics.BeginImageContext(new CGSize(matrix.Width * 10, matrix.Height * 10));
        CGContext context = UIGraphics.GetCurrentContext();

        CGColor black = new CGColor(0f, 0f, 0f);
        CGColor white = new CGColor(1.0f, 1.0f, 1.0f);
        for (int x = 0; x < matrix.Width; x++)
        {
            for (int y = 0; y < matrix.Height; y++)
            {

                context.SetFillColor(matrix[x, y] ? black : white);
                context.FillRect(new CGRect(x*10, y*10, 10, 10));

            }
        }


        UIImage img = UIGraphics.GetImageFromCurrentImageContext();

        UIGraphics.EndImageContext();

        return img;
    }
}

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