WPF截屏实现

码客说

发布于 2021-07-12 03:41:58

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代码可运行

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代码可运行

前言

使用C#直接截屏的话有两个问题

截图效率不高
内存释放不及时，如果间隔时间较短进行截屏，就会导致内存占用不断上升最终程序崩溃

为了解决这个问题这里就采用了利用nircmd.exe截屏，但是这个工具截屏不能设置截屏后的大小，所以我们在做一下压缩并删除之前文件就行了。

正文

使用nircmd.exe截屏

官网：http://www.nirsoft.net/utils/nircmd.html

链接：https://pan.baidu.com/s/1AyGNHN5XM5v08gjGx3y6Dw 提取码：sytu

nircmd.exe savescreenshot "d:\temp.png"

这种方法其实各种语言都可以使用。

首先在项目下放入下载的exe路径：Tools/nircmd.exe

项目右键=>属性=>生成事件=>生成前事件命令行添加如下

xcopy /Y /i /e $(ProjectDir)\Tools $(TargetDir)\Tools

目的是为了打包运行时能够找到 nircmd.exe

工具类

using System;
using System.Diagnostics;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;

namespace SchoolClient.Utils
{
    internal class ZScreenUtil2
    {
        public static bool CaptureScreenSave(string filePath)
        {
            int lastindex = filePath.LastIndexOf(Path.DirectorySeparatorChar);
            if (lastindex < filePath.Length)
            {
                string fileFolder = filePath.Substring(0, lastindex);
                string filename = filePath.Substring(lastindex + 1);
                string tempFilePath = fileFolder + Path.DirectorySeparatorChar + "_temp_" + filename;

                string basePath = AppDomain.CurrentDomain.BaseDirectory;
                string toolsPath = System.IO.Path.Combine(basePath, "Tools");

                Process mps = new Process();
                ProcessStartInfo mpsi = new ProcessStartInfo("nircmd.exe", "savescreenshot \"" + tempFilePath+"\"" )
                {
                    WorkingDirectory = toolsPath,
                    UseShellExecute = true,
                    RedirectStandardInput = false,
                    RedirectStandardOutput = false,
                    CreateNoWindow = true,
                    WindowStyle = ProcessWindowStyle.Hidden
                };
                mps.StartInfo = mpsi;
                mps.Start();
                mps.WaitForExit();
                mps.Close();

                bool result = GetPicThumbnail(tempFilePath, filePath, 1920, 1080, 80, true);
                return result;
            }
            else
            {
                return false;
            }
        }

        /// 无损压缩图片
        /// <param name="sFile">原图片</param>
        /// <param name="dFile">压缩后保存位置</param>
        /// <param name="dWidth"></param>
        /// <param name="dHeight">高度</param>
        /// <param name="ratio">压缩质量(数字越小压缩率越高) 1-100</param>
        /// <returns></returns>
        public static bool GetPicThumbnail(string sFile, string dFile, int dWidth, int dHeight, int ratio, bool deleteSFile)
        {
            System.Drawing.Image iSource = System.Drawing.Image.FromFile(sFile);
            ImageFormat tFormat = iSource.RawFormat;

            //按比例缩放
            Size tem_size = new Size(iSource.Width, iSource.Height);
            int sW;
            int sH;
            if (tem_size.Width > dHeight || tem_size.Width > dWidth)
            {
                if ((tem_size.Width * dHeight) > (tem_size.Width * dWidth))
                {
                    sW = dWidth;
                    sH = (dWidth * tem_size.Height) / tem_size.Width;
                }
                else
                {
                    sH = dHeight;
                    sW = (tem_size.Width * dHeight) / tem_size.Height;
                }
            }
            else
            {
                sW = tem_size.Width;
                sH = tem_size.Height;
            }

            Bitmap ob = new Bitmap(dWidth, dHeight);
            Graphics g = Graphics.FromImage(ob);

            g.Clear(Color.WhiteSmoke);
            g.CompositingQuality = CompositingQuality.HighQuality;
            g.SmoothingMode = SmoothingMode.HighQuality;
            g.InterpolationMode = InterpolationMode.HighQualityBicubic;

            g.DrawImage(
                    iSource,
                    new Rectangle((dWidth - sW) / 2,(dHeight - sH) / 2, sW, sH),
                    0,
                    0,
                    iSource.Width,
                    iSource.Height,
                    GraphicsUnit.Pixel
                );

            g.Dispose();
            //以下代码为保存图片时，设置压缩质量
            EncoderParameters ep = new EncoderParameters();
            long[] qy = new long[1];
            qy[0] = ratio;//设置压缩的比例1-100
            EncoderParameter eParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, qy);
            ep.Param[0] = eParam;
            try
            {
                ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders();
                ImageCodecInfo jpegICIinfo = null;
                for (int x = 0; x < arrayICI.Length; x++)
                {
                    if (arrayICI[x].FormatDescription.Equals("JPEG"))
                    {
                        jpegICIinfo = arrayICI[x];
                        break;
                    }
                }
                if (jpegICIinfo != null)
                {
                    ob.Save(dFile, jpegICIinfo, ep);//dFile是压缩后的新路径
                }
                else
                {
                    ob.Save(dFile, tFormat);
                }
                return true;
            }
            catch
            {
                return false;
            }
            finally
            {
                iSource.Dispose();
                ob.Dispose();

                if (deleteSFile)
                {
                    FileInfo di = new FileInfo(sFile);
                    if (di.Exists)
                    {
                        try
                        {
                            di.Delete();
                        }
                        catch (Exception)
                        {
                        }
                    }
                }
            }
        }
    }
}