Detaillierte Einführung in den Beispielcode zur Implementierung der Screenshot-Funktion im QQ-Stil in C#

In diesem Artikel wird hauptsächlich der Beispielcode von C# zur Implementierung der Screenshot-Funktion im QQ-Stil vorgestellt. Der Herausgeber findet ihn recht gut, daher werde ich ihn jetzt mit Ihnen teilen und als Referenz verwenden. Folgen wir dem Editor und werfen wir einen Blick darauf.

Diese Funktion besteht aus zwei Teilen. Der erste Teil ist der Formularcode und der andere Teil ist eine Hilfsmethode. Veröffentlichen Sie den Code direkt als Referenz:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using ImageClassLib;
namespace ImageShear
{
  public partial class Demo: Form
  {
    public Demo()
    {
      InitializeComponent();
    }
    #region 点击打开图像
    public string strHeadImagePath; //打开图片的路径
    Bitmap Bi; //定义位图对像
    private void button1_Click(object sender, EventArgs e)
    {
      openFileDialog1.Filter = "*.gif|*.jpg|*.JPEG|*.JPEG|*.bmp|*.bmp";     //设置读取图片类型
      if (openFileDialog1.ShowDialog() == DialogResult.OK)
      {
        try
        {
          strHeadImagePath = openFileDialog1.FileName;
          //this.Show(strHeadImagePath);
          Bi = new Bitmap(strHeadImagePath); //使用打开的图片路径创建位图对像
          ImageCut1 IC = new ImageCut1(40, 112, this.pictureBox1.Width, this.pictureBox1.Height);   //实例化ImageCut类，四个参数据分别表示为：x、y、width、heigth，（40、112）表示pictureBox1的Lcation的坐标，（120、144）表示pictureBox1控件的宽度和高度
          this.pictureBox1.Image = IC.KiCut1((Bitmap)(this.GetSelectImage(this.pictureBox1.Width, this.pictureBox1.Height)));   //（120、144）表示pictureBox1控件的宽度和高度
          //this.pictureBox1.Image = (this.GetSelectImage(120, 144));
        }
        catch (Exception ex)
        {
          MessageBox.Show("格式不对");
          ex.ToString();
        }
      }
    }
    #endregion
    #region 定义显示图像方法，即将打开的图像在pictureBox1控件显示
    public void Show(string strHeadImagePath)
    {
      this.pictureBox1.Load(@strHeadImagePath);  //
    }
    #endregion
    #region 获取图像
    /// <summary>
    /// 获取指定宽度和高度的图像即使图片和pictureBox1控件一样宽和高，返回值为图片Image
    /// </summary>
    /// <param name="Width表示宽"></param>
    /// <param name="Height表示高"></param>
    /// <returns></returns>
    public Image GetSelectImage(int Width, int Height)
    {
      //Image initImage = this.pictureBox1.Image;
      Image initImage = Bi;
      //原图宽高均小于模版，不作处理，直接保存 
      if (initImage.Width <= Width && initImage.Height <= Height)
      {
        //initImage.Save(fileSaveUrl, System.Drawing.Imaging.ImageFormat.Jpeg);
        return initImage;
      }
      else
      {
        //原始图片的宽、高 
        int initWidth = initImage.Width;
        int initHeight = initImage.Height;

        //非正方型先裁剪为正方型 
        if (initWidth != initHeight)
        {
          //截图对象 
          System.Drawing.Image pickedImage = null;
          System.Drawing.Graphics pickedG = null;

          //宽大于高的横图 
          if (initWidth > initHeight)
          {
            //对象实例化 
            pickedImage = new System.Drawing.Bitmap(initHeight, initHeight);
            pickedG = System.Drawing.Graphics.FromImage(pickedImage);
            //设置质量 
            pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
            pickedG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            //定位 
            Rectangle fromR = new Rectangle((initWidth - initHeight) / 2, 0, initHeight, initHeight);
            Rectangle toR = new Rectangle(0, 0, initHeight, initHeight);
            //画图 
            pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel);
            //重置宽 
            initWidth = initHeight;
          }
          //高大于宽的竖图 
          else
          {
            //对象实例化
            pickedImage = new System.Drawing.Bitmap(initWidth, initWidth);
            pickedG = System.Drawing.Graphics.FromImage(pickedImage);
            //设置质量 
            pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
            pickedG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            //定位 
            Rectangle fromR = new Rectangle(0, (initHeight - initWidth) / 2, initWidth, initWidth);
            Rectangle toR = new Rectangle(0, 0, initWidth, initWidth);
            //画图 
            pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel);
            //重置高 
            initHeight = initWidth;
          }

          initImage = (System.Drawing.Image)pickedImage.Clone();
          //        //释放截图资源 
          pickedG.Dispose();
          pickedImage.Dispose();
        }

        return initImage;
      }
    }
    #endregion
    #region 点击button2按钮事件
    private void button2_Click(object sender, EventArgs e)
    {
      this.label1.Text = "裁剪后的图片宽度："+this.pictureBox2.Width.ToString();
      this.label2.Text = "裁剪后的图片高度："+this.pictureBox2.Height.ToString();
    }
    #endregion
    #region 缩放、裁剪图像用到的变量
    /// <summary>
    /// 
    /// </summary>
    int x1;   //鼠标按下时横坐标
    int y1;   //鼠标按下时纵坐标
    int width; //所打开的图像的宽
    int heigth; //所打开的图像的高
    bool HeadImageBool = false;  // 此布尔变量用来判断pictureBox1控件是否有图片
    #endregion
    #region 画矩形使用到的变量
    Point p1;  //定义鼠标按下时的坐标点
    Point p2;  //定义移动鼠标时的坐标点
    Point p3;  //定义松开鼠标时的坐标点
    #endregion
    #region 鼠标按下时发生的事件
    private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
    {
      this.Cursor = Cursors.Cross;
      this.p1 = new Point(e.X, e.Y);
      x1 = e.X;
      y1 = e.Y;
      if (this.pictureBox1.Image != null)
      {
        HeadImageBool = true;
      }
      else
      {
        HeadImageBool = false;
      }
    }
    #endregion
    #region 移动鼠标发生的事件
    private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
    {
      if (this.Cursor == Cursors.Cross)
      {
        this.p2 = new Point(e.X, e.Y);
        if ((p2.X - p1.X) > 0 && (p2.Y - p1.Y) > 0)   //当鼠标从左上角向开始移动时P3坐标
        {
          this.p3 = new Point(p1.X, p1.Y);
        }
        if ((p2.X - p1.X) < 0 && (p2.Y - p1.Y) > 0)   //当鼠标从右上角向左下方向开始移动时P3坐标
        {
          this.p3 = new Point(p2.X, p1.Y);
        }
        if ((p2.X - p1.X) > 0 && (p2.Y - p1.Y) < 0)   //当鼠标从左下角向上开始移动时P3坐标
        {
          this.p3 = new Point(p1.X, p2.Y);
        }
        if ((p2.X - p1.X) < 0 && (p2.Y - p1.Y) < 0)   //当鼠标从右下角向左方向上开始移动时P3坐标
        {
          this.p3 = new Point(p2.X, p2.Y);
        }
        this.pictureBox1.Invalidate(); //使控件的整个图面无效，并导致重绘控件
      }
    }
    #endregion
    #region 松开鼠标发生的事件，实例化ImageCut1类对像
    ImageCut1 IC1; //定义所画矩形的图像对像
    private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
    {
      if (HeadImageBool)
      {
        width = this.pictureBox1.Image.Width;
        heigth = this.pictureBox1.Image.Height;
        if ((e.X - x1) > 0 && (e.Y - y1) > 0)  //当鼠标从左上角向右下方向开始移动时发生
        {
          IC1 = new ImageCut1(x1, y1, Math.Abs(e.X - x1), Math.Abs(e.Y - y1));  //实例化ImageCut1类
        }
        if ((e.X - x1) < 0 && (e.Y - y1) > 0)  //当鼠标从右上角向左下方向开始移动时发生
        {
          IC1 = new ImageCut1(e.X, y1, Math.Abs(e.X - x1), Math.Abs(e.Y - y1));  //实例化ImageCut1类
        }
        if ((e.X - x1) > 0 && (e.Y - y1) < 0)  //当鼠标从左下角向右上方向开始移动时发生
        {
          IC1 = new ImageCut1(x1, e.Y, Math.Abs(e.X - x1), Math.Abs(e.Y - y1));  //实例化ImageCut1类
        }
        if ((e.X - x1) < 0 && (e.Y - y1) < 0)  //当鼠标从右下角向左上方向开始移动时发生
        {
          IC1 = new ImageCut1(e.X, e.Y, Math.Abs(e.X - x1), Math.Abs(e.Y - y1));   //实例化ImageCut1类
        }
        this.pictureBox2.Width = (IC1.KiCut1((Bitmap)(this.pictureBox1.Image))).Width;
        this.pictureBox2.Height = (IC1.KiCut1((Bitmap)(this.pictureBox1.Image))).Height;
        this.pictureBox2.Image = IC1.KiCut1((Bitmap)(this.pictureBox1.Image));
        this.Cursor = Cursors.Default;
      }
      else
      {
        this.Cursor = Cursors.Default;
      }
    }
    #endregion
    #region 获取所选矩形图像
    /// <summary>
    /// 
    /// </summary>
    /// <param name="Width"></param>
    /// <param name="Height"></param>
    /// <returns></returns>
    public Image GetSelectImage1(int Width, int Height)
    {
      Image initImage = this.pictureBox1.Image;
      //Image initImage = Bi;
      //原图宽高均小于模版，不作处理，直接保存 
      if (initImage.Width <= Width && initImage.Height <= Height)
      {
        //initImage.Save(fileSaveUrl, System.Drawing.Imaging.ImageFormat.Jpeg);
        return initImage;
      }
      else
      {
        //原始图片的宽、高 
        int initWidth = initImage.Width;
        int initHeight = initImage.Height;

        //非正方型先裁剪为正方型 
        if (initWidth != initHeight)
        {
          //截图对象 
          System.Drawing.Image pickedImage = null;
          System.Drawing.Graphics pickedG = null;

          //宽大于高的横图 
          if (initWidth > initHeight)
          {
            //对象实例化 
            pickedImage = new System.Drawing.Bitmap(initHeight, initHeight);
            pickedG = System.Drawing.Graphics.FromImage(pickedImage);
            //设置质量 
            pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
            pickedG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            //定位 
            Rectangle fromR = new Rectangle((initWidth - initHeight) / 2, 0, initHeight, initHeight);
            Rectangle toR = new Rectangle(0, 0, initHeight, initHeight);
            //画图 
            pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel);
            //重置宽 
            initWidth = initHeight;
          }
          //高大于宽的竖图 
          else
          {
            //对象实例化
            pickedImage = new System.Drawing.Bitmap(initWidth, initWidth);
            pickedG = System.Drawing.Graphics.FromImage(pickedImage);
            //设置质量 
            pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
            pickedG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            //定位 
            Rectangle fromR = new Rectangle(0, (initHeight - initWidth) / 2, initWidth, initWidth);
            Rectangle toR = new Rectangle(0, 0, initWidth, initWidth);
            //画图 
            pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel);
            //重置高 
            initHeight = initWidth;
          }

          initImage = (System.Drawing.Image)pickedImage.Clone();
          //        //释放截图资源 
          pickedG.Dispose();
          pickedImage.Dispose();
        }

        return initImage;
      }
    }
    #endregion
    #region 重新绘制pictureBox1控件，即移动鼠标画矩形
    private void pictureBox1_Paint(object sender, PaintEventArgs e)
    {
      if (HeadImageBool)
      {
        Pen p = new Pen(Color.Black, 1);//画笔
        p.DashStyle = System.Drawing.Drawing2D.DashStyle.Dash;
        //Bitmap bitmap = new Bitmap(strHeadImagePath);
        Bitmap bitmap = Bi;
        Rectangle rect = new Rectangle(p3, new Size(System.Math.Abs(p2.X - p1.X), System.Math.Abs(p2.Y - p1.Y)));
        e.Graphics.DrawRectangle(p, rect);
      }
      else
      {

      }
    }
    #endregion
  }
}

Der zweite Teil ist die Hilfsmethodenklasse

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
namespace ImageClassLib
{
  public class ImageCut1
  {
    #region 剪裁图片方法
    /// <summary> 
    /// 剪裁 -- 用GDI+ 
    /// </summary> 
    /// <param name="b">原始Bitmap,即需要裁剪的图片</param> 
    /// <param name="StartX">开始坐标X</param> 
    /// <param name="StartY">开始坐标Y</param> 
    /// <param name="iWidth">宽度</param> 
    /// <param name="iHeight">高度</param> 
    /// <returns>剪裁后的Bitmap</returns> 
    public Bitmap KiCut1(Bitmap b) 
    { 
      if (b == null) 
      { 
        return null; 
      } 
    
      int w = b.Width; 
      int h = b.Height; 
    
      if (X >= w || Y >= h) 
      { 
        return null; 
      } 
    
      if (X + Width > w) 
      { 
        Width = w - X; 
      } 
    
      if (Y + Height > h) 
      { 
        Height = h - Y; 
      } 
    
      try
      { 
        Bitmap bmpOut = new Bitmap(Width, Height, PixelFormat.Format24bppRgb); 
    
        Graphics g = Graphics.FromImage(bmpOut);
        // Create rectangle for displaying image.
        Rectangle destRect = new Rectangle(0, 0, Width, Height);    //所画的矩形正确，它指定所绘制图像的位置和大小。 将图像进行缩放以适合该矩形。

        // Create rectangle for source image.
        Rectangle srcRect = new Rectangle(X, Y, Width, Height);   //srcRect参数指定要绘制的 image 对象的矩形部分。 将此部分进行缩放以适合 destRect 参数所指定的矩形。

        g.DrawImage(b, destRect, srcRect, GraphicsUnit.Pixel);
        //resultG.DrawImage(initImage, new System.Drawing.Rectangle(0, 0, side, side), new System.Drawing.Rectangle(0, 0, initWidth, initHeight), System.Drawing.GraphicsUnit.Pixel);
        g.Dispose(); 
        return bmpOut; 
      } 
      catch
      { 
        return null; 
      } 
    }
    #endregion
    #region ImageCut1类的构造函数
    public int X; 
    public int Y; 
    public int Width ; 
    public int Height;
    /// <summary>
    /// ImageCut1类的构造函数，ImageCut1类用来获取鼠标在pictureBox1控件所画矩形内的图像
    /// </summary>
    /// <param name="x表示鼠标在pictureBox1控件上按下时的横坐标"></param>
    /// <param name="y表示鼠标在pictureBox1控件上按下时的纵坐标"></param>
    /// <param name="width表示鼠标在pictureBox1控件上松开鼠标的宽度"></param>
    /// <param name="heigth表示鼠标在pictureBox1控件上松开鼠标的高度"></param>
    public ImageCut1(int x, int y, int width, int heigth)
    {
      X = x;
      Y = y;
      Width = width;
      Height = heigth;
    }
    #endregion
  }
}

Der erzielte Effekt ist wie folgt:

Das Obige ist die detaillierte Einführung des zu implementierenden Beispielcodes von C# Weitere verwandte Inhalte finden Sie auf der chinesischen PHP-Website (www.php.cn)!