c#调用c++ DLL(opencv)示例源码

【实例截图】

【核心代码】

using Emgu.CV;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;
using System.Text;
using System.Web;
using System.Windows.Forms;

namespace RollerTest
{
    public partial class Form1 : Form
    {
        //    [DllImport("Project6.dll", EntryPoint = "PrintString")]
        [DllImport("Project6.dll", EntryPoint = "opencvtest")]
        //  [DllImport("test0909.dll", EntryPoint = "main")]
        public static extern int opencvtest(byte[] hello);

        public Form1()
        {
            InitializeComponent();
        }


        private string pathname = string.Empty;
        private void button1_Click(object sender, EventArgs e)
        {
            OpenFileDialog file = new OpenFileDialog();
            file.InitialDirectory = ".";
            file.Filter = "所有文件(*.*)|*.*";
            file.ShowDialog();
            if (file.FileName != string.Empty)
            {
                try
                {
                    pathname = file.FileName;   //获得文件的绝对路径
                    this.pictureBox1.Load(pathname);
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
            }
        }


       


        private void pictureBox2_Click(object sender, EventArgs e)
        {
            try
            {
             // string str = "D:/0002.jpg";
           //  int a =    PrintString(Encoding.ASCII.GetBytes(pathname));
             //   MessageBox.Show(a.ToString());
               
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message);
            }

        }

        private void button2_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
       
        private void pictureBox4_Click(object sender, EventArgs e)
        {
            Bitmap bmp = new Bitmap("1.jpg");

            // pictureBox1.Image = bmp;
            int stride;
            byte[] source = GetBGRValues(bmp, out stride);
            int channel = Image.GetPixelFormatSize(bmp.PixelFormat) / 8;
            opencvtest(source, bmp.Width, bmp.Height, channel); //opencv对内存操作，画了一个圈
            pictureBox1.Image = getBitmapByBytes(source, bmp.Width, bmp.Height, stride, bmp.PixelFormat);   //从byte[]数组中获取到的图像已经有画圈了，证明传输通信成功
        }



        [DllImport("Project6.dll", EntryPoint = "opencvtest", SetLastError = true, CharSet = CharSet.Ansi)]
        extern static int opencvtest(byte[] src, int w, int h, int channel);

       

        /// <summary>
        /// 生成灰度图的调色板
        /// </summary>
        /// <returns></returns>
        public static ColorPalette getGrayPalette()
        {
            // 下面的代码是为了修改生成位图的索引表，从伪彩修改为灰度 
            ColorPalette tempPalette;
            using (Bitmap tempBmp = new Bitmap(1, 1, System.Drawing.Imaging.PixelFormat.Format8bppIndexed))
            {
                tempPalette = tempBmp.Palette;
            }
            for (int i = 0; i < 256; i  )
            {
                tempPalette.Entries[i] = System.Drawing.Color.FromArgb(i, i, i);
            }
            return tempPalette;
        }

        /// <summary>
        /// 从图像Byte数组获取Bitmap
        /// </summary>
        /// <param name="src"></param>
        /// <param name="w"></param>
        /// <param name="h"></param>
        /// <param name="stride"></param>
        /// <param name="format"></param>
        /// <returns></returns>
        public static Bitmap getBitmapByBytes(byte[] src, int w, int h, int stride, PixelFormat format)
        {
            IntPtr ptr = getBytesPtr(src);

            int rowBytes = w * Image.GetPixelFormatSize(format) / 8;
            byte[] rgbValues = new byte[stride * h];
            for (var i = 0; i < h; i  )
            {
                //int len = stride - (stride-rowBytes);
                Marshal.Copy(ptr, rgbValues, i * stride, rowBytes);   //对齐
                ptr  = rowBytes; // next row
            }
            //Marshal.FreeHGlobal(ptr);
            ptr = getBytesPtr(rgbValues);

            Bitmap bitmap = new Bitmap(w, h, stride, format, ptr);
            if (format == PixelFormat.Format8bppIndexed)
            {
                bitmap.Palette = getGrayPalette();   //如果是单通道灰度图，默认的bitmap调色板不对，需要手动设置
            }
            return bitmap;
        }

        /// <summary>
        /// 获取bytes数组的头指针，非托管
        /// </summary>
        /// <param name="bytes"></param>
        /// <returns></returns>
        public static IntPtr getBytesPtr(byte[] bytes)
        {
            GCHandle hObject = GCHandle.Alloc(bytes, GCHandleType.Pinned);
            return hObject.AddrOfPinnedObject();
        }

        /// <summary>
        /// 获取bitmap的byte数据，并输出stride
        /// </summary>
        /// <param name="bmp"></param>
        /// <param name="stride"></param>
        /// <returns></returns>
        public static byte[] GetBGRValues(Bitmap bmp, out int stride)
        {
            var rect = new Rectangle(0, 0, bmp.Width, bmp.Height);
            var bmpData = bmp.LockBits(rect, System.Drawing.Imaging.ImageLockMode.ReadOnly, bmp.PixelFormat);
            stride = bmpData.Stride;
            //int channel = bmpData.Stride / bmp.Width; 
            var rowBytes = bmpData.Width * Image.GetPixelFormatSize(bmp.PixelFormat) / 8;
            var imgBytes = bmp.Height * rowBytes;
            byte[] rgbValues = new byte[imgBytes];
            IntPtr ptr = bmpData.Scan0;
            for (var i = 0; i < bmp.Height; i  )
            {
                Marshal.Copy(ptr, rgbValues, i * rowBytes, rowBytes);   //对齐
                ptr  = bmpData.Stride; // next row
            }
            bmp.UnlockBits(bmpData);

            return rgbValues;
        }



        [DllImport("Project6.dll", EntryPoint = "opencvtest", SetLastError = true, CharSet = CharSet.Ansi)]
        extern static int dlltest(byte[] src, int w, int h, out byte[] img);

        private void pictureBox3_Click(object sender, EventArgs e)
        {

        }
    }
}