通过COMPORT在C＃中打印位图图像POS打印机 [英] Printing a Bit map image to pos printer via comport in C#

问题描述

我直接打印的收据到POS打印机通过以下面的方式，

I'm directly printing my receipt to the POS printer via serial port in the following way,

        SerialPort port = new SerialPort("com6", 9100, Parity.None, 8, StopBits.One);
        port.Open();
        port.Write("Some Text");
        port.Close();

我的问题是我要如何使用上述方法来打印一个位图图像？任何帮助将不胜感激。

My question is how I'm going to print a Bitmap image using the above method? Any help would be grateful.

我还没有决定去与微软POS for.net，因为它是缓慢的，需要时间来初始化打印机，其中客户不喜欢等待。

I have not decided to go with Microsoft POS for.net, because it is slow and takes time to initialize the printer, where clients doesn't like to wait.

感谢。

推荐答案

这应该让你从位图字符串，你将能够发送到打印机：

This should get you a string from bitmap that you would be able to send to printer:

    public string GetLogo()
    {
        string logo = "";
        if (!File.Exists(@"C:\bitmap.bmp"))
            return null;
         BitmapData data = GetBitmapData(@"C:\bitmap.bmp");
         BitArray dots = data.Dots;
         byte[] width = BitConverter.GetBytes(data.Width);

         int offset = 0;
         MemoryStream stream = new MemoryStream();
         BinaryWriter bw = new BinaryWriter(stream);

         bw.Write((char)0x1B);
         bw.Write('@');

         bw.Write((char)0x1B);
         bw.Write('3');
         bw.Write((byte)24);

         while (offset < data.Height)
         {
             bw.Write((char)0x1B);
             bw.Write('*');         // bit-image mode
             bw.Write((byte)33);    // 24-dot double-density
             bw.Write(width[0]);  // width low byte
             bw.Write(width[1]);  // width high byte

             for (int x = 0; x < data.Width; ++x)
             {
                 for (int k = 0; k < 3; ++k)
                 {
                     byte slice = 0;
                     for (int b = 0; b < 8; ++b)
                     {
                         int y = (((offset / 8) + k) * 8) + b;
                         // Calculate the location of the pixel we want in the bit array.
                         // It'll be at (y * width) + x.
                         int i = (y * data.Width) + x;

                         // If the image is shorter than 24 dots, pad with zero.
                         bool v = false;
                         if (i < dots.Length)
                         {
                             v = dots[i];
                         }
                         slice |= (byte)((v ? 1 : 0) << (7 - b));
                     }

                     bw.Write(slice);
                 }
             }
             offset += 24;
             bw.Write((char)0x0A);
         }
         // Restore the line spacing to the default of 30 dots.
         bw.Write((char)0x1B);
         bw.Write('3');
         bw.Write((byte)30);

         bw.Flush();
         byte[] bytes = stream.ToArray();
         return logo + Encoding.Default.GetString(bytes);
    }

    public BitmapData GetBitmapData(string bmpFileName)
    {
        using (var bitmap = (Bitmap)Bitmap.FromFile(bmpFileName))
        {
            var threshold = 127;
            var index = 0;
            double multiplier = 570; // this depends on your printer model. for Beiyang you should use 1000
            double scale = (double)(multiplier/(double)bitmap.Width);
            int xheight = (int)(bitmap.Height * scale);
            int xwidth = (int)(bitmap.Width * scale);
            var dimensions = xwidth * xheight;
            var dots = new BitArray(dimensions);

            for (var y = 0; y < xheight; y++)
            {
                for (var x = 0; x < xwidth; x++)
                {
                    var _x = (int)(x / scale);
                    var _y = (int)(y / scale);
                    var color = bitmap.GetPixel(_x, _y);
                    var luminance = (int)(color.R * 0.3 + color.G * 0.59 + color.B * 0.11);
                    dots[index] = (luminance < threshold);
                    index++;
                }
            }

            return new BitmapData()
            {
                Dots = dots,
                Height = (int)(bitmap.Height*scale),
                Width = (int)(bitmap.Width*scale)
            };
        }
    }

    public class BitmapData
    {
        public BitArray Dots
        {
            get;
            set;
        }

        public int Height
        {
            get;
            set;
        }

        public int Width
        {
            get;
            set;
        }
    }

这篇关于通过COMPORT在C＃中打印位图图像POS打印机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！