自定义控件实现图像的显示和放大缩小，平移，右击菜单选择“自适应窗口”“保存图像”

Posted 2021-02-04 mazai

前面介绍了2个控件组合在一起实现，对PictureBox控件的操作，今天我们自己新建一个控件来自己用。

新建一个Windows窗体解决方案，添加“用户控件”，把PictureBox控件拖到指定的区域，给我们要自己定义的控件改下名字UserControl_Display

界面就完成了，现在我们要自定义的控件添加事件和右击菜单（contextMenuStrip1）控件

 

  1 using System;
  2 using System.Collections.Generic;
  3 using System.ComponentModel;
  4 using System.Drawing;
  5 using System.Data;
  6 using System.Linq;
  7 using System.Text;
  8 using System.Threading.Tasks;
  9 using System.Windows.Forms;
 10 
 11 namespace _自定义控件显示图片
 12 {
 13     public partial class UserControl_Display : UserControl
 14     {
 15 
 16         public System.Drawing.Point mouseDownPoint;//存储鼠标焦点的全局变量
 17         public bool isSelected = false;
 18         public int width;
 19         public int height;
 20      
 21 
 22         public UserControl_Display()
 23         {
 24             InitializeComponent();
 25         }
 26 
 27         //这个是显示图片用的
 28         public  void Display(Image  image)
 29         {
 30             pictureBox1.Image = image;
 31 
 32             width = pictureBox1.Width;//控件的原始大小保存一下，恢复的时候用
 33             height = pictureBox1.Height;      
 36         }
 37 
 38          // 在MouseUp处获知鼠标是否松开，终止拖动操作；
 39         private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
 40         {
 41             isSelected = false;
 42         }
 43 
 44         private void pictureBox1_MouseEnter(object sender, EventArgs e)
 45         {
 46             pictureBox1.Focus();
 47             pictureBox1.Cursor = Cursors.SizeAll;
 48         }
 49 
 50         //在MouseDown处获知鼠标是否按下，并记录下此时的鼠标坐标值；
 51         private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
 52         {
 53             if (e.Button == MouseButtons.Left)
 54             {
 55                 mouseDownPoint.X = Cursor.Position.X;  //注：全局变量mouseDownPoint前面已定义为Point类型  
 56                 mouseDownPoint.Y = Cursor.Position.Y;
 57                 isSelected = true;
 58             }

 61         }
 62 
 63         //图片平移,在MouseMove处添加拖动函数操作
 64         private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
 65         {
 66             if (isSelected && IsMouseInPanel())//确定已经激发MouseDown事件，和鼠标在picturebox的范围内
 67             {
 68                 this.pictureBox1.Left = this.pictureBox1.Left + (Cursor.Position.X - mouseDownPoint.X);
 69                 this.pictureBox1.Top = this.pictureBox1.Top + (Cursor.Position.Y - mouseDownPoint.Y);
 70                 mouseDownPoint.X = Cursor.Position.X;
 71                 mouseDownPoint.Y = Cursor.Position.Y;
 72             }
 73         }
 74 
 75         private void pictureBox1_MouseWheel(object sender, MouseEventArgs e)
 76         {
 77             double scale = 1;
 78             if (pictureBox1.Height > 0)
 79             {
 80                 scale = (double)pictureBox1.Width / (double)pictureBox1.Height;
 81             }
 82             pictureBox1.Width += (int)(e.Delta * scale);
 83             pictureBox1.Height += e.Delta;
 84         }
 85 
 86 
 87         private bool IsMouseInPanel()
 88         {
 89             if (this.pictureBox1.Left < PointToClient(Cursor.Position).X
 90                     && PointToClient(Cursor.Position).X < this.pictureBox1.Left
 91                     + this.pictureBox1.Width && this.pictureBox1.Top
 92                     < PointToClient(Cursor.Position).Y && PointToClient(Cursor.Position).Y
 93                     < this.pictureBox1.Top + this.pictureBox1.Height)
 94             {
 95                 return true;
 96             }
 97             else
 98             {
 99                 return false;
100             }
101 
102         }
103 
104 
105         /// <summary>
106         /// 右击菜单的保存图像
107         /// </summary>
108         /// <param name="sender"></param>
109         /// <param name="e"></param>
110         private void SaveImage_Click(object sender, EventArgs e)
111         {
112             Image image = this.pictureBox1.Image;
113             string imageName = DateTime.Now.ToString("HH时MM分SS秒") + ".bmp";
114             image.Save(@imageName);
115         }
116 
117         //右击菜单的图像适应控件的大小
118         private void ImageFitPictureBox_Click(object sender, EventArgs e)
119         { 
120             pictureBox1.Width = width;//控件的大小恢复
121             pictureBox1.Height = height;
122 
123             //PictureBox控件的位置
124             pictureBox1.Left = 1;
125             pictureBox1.Top = 1;       
126         }
127     }
128 }