昨天剛學會了如何實現PictureBox控件中的圖像自動縮放和平移，下面我把過程給大家說一下：

參考了：https://www.cnblogs.com/jinqier/p/3497201.html

1、首先要拖一個控件，Panel控件作為容器

2、然後父容器裏面拖一個PictureBox控件，設置屬性為“”停靠在父容器“”

pictureBox1.SizeMode = PictureBoxSizeMode.Zoom;
pictureBox1.Dock = DockStyle.None;

3‘設置背景色了。Panel 和PictureBox的背景色要設置成一樣的，我這裏設置的都是為Blue;

4、為PictureBox添加事件了，下面是代碼

 1  public System.Drawing.Point mouseDownPoint;//存儲鼠標焦點的全局變量
 2         public bool isSelected = false;
 3         private void Form1_Load(object sender, EventArgs e)
 4         {
 5             pictureBox1.SizeMode = PictureBoxSizeMode.Zoom;
 6             pictureBox1.Dock = DockStyle.None;
 
 7           
 8         }
 9 　　　　　　//這個事件是鼠標滑輪滾動的觸發事件，可以在Designer.cs中註冊。
　　　　　　this.pictureBox1.MouseWheel += new System.Windows.Forms.MouseEventHandler(this.pictureBox1_MouseWheel);
　　　　　　this.pictureBox1.MouseDown += new System.Windows.Forms.MouseEventHandler(this.pictureBox1_MouseDown);
　　　　　　this.pictureBox1.MouseEnter += new System.EventHandler(this.pictureBox1_MouseEnter);
 
　　　　　　this.pictureBox1.MouseMove += new System.Windows.Forms.MouseEventHandler(this.pictureBox1_MouseMove);
　　　　　　this.pictureBox1.MouseUp += new System.Windows.Forms.MouseEventHandler(this.pictureBox1_MouseUp);
　　　　　　　　　
10         private void pictureBox1_MouseWheel(object sender, MouseEventArgs e)
11         {
12             double scale = 1;
13             if (pictureBox1.Height > 0)
14             {
15                 scale = (double)pictureBox1.Width / (double)pictureBox1.Height;
16             }
17             pictureBox1.Width += (int)(e.Delta * scale);
18             pictureBox1.Height += e.Delta;
19         }
20         private void pictureBox1_MouseEnter(object sender, EventArgs e)
21         {
22             pictureBox1.Focus();
23             pictureBox1.Cursor = Cursors.SizeAll;
24         }
25 
26         //在MouseDown處獲知鼠標是否按下，並記錄下此時的鼠標坐標值；
27         private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
28         {
29             if (e.Button == MouseButtons.Left)
30             {
31                 mouseDownPoint.X = Cursor.Position.X;  //註：全局變量mouseDownPoint前面已定義為Point類型  
32                 mouseDownPoint.Y = Cursor.Position.Y;
33                 isSelected = true;
34             }
35         }
36 
37         //在MouseUp處獲知鼠標是否松開，終止拖動操作；
38         private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
39         {
40             isSelected = false;
41 
42         }
43 
44         private bool IsMouseInPanel()
45         {
46             if (this.panel_Picture.Left < PointToClient(Cursor.Position).X
47                     && PointToClient(Cursor.Position).X < this.panel_Picture.Left
48                     + this.panel_Picture.Width && this.panel_Picture.Top
49                     < PointToClient(Cursor.Position).Y && PointToClient(Cursor.Position).Y
50                     < this.panel_Picture.Top + this.panel_Picture.Height)
51             {
52                 return true;
53             }
54             else
55             {
56                 return false;
57             }       
60         }
61 
62         //圖片平移,在MouseMove處添加拖動函數操作
63         private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
64         {
65             if (isSelected && IsMouseInPanel())//確定已經激發MouseDown事件，和鼠標在picturebox的範圍內
66             {
67                 this.pictureBox1.Left = this.pictureBox1.Left + (Cursor.Position.X - mouseDownPoint.X);
68                 this.pictureBox1.Top = this.pictureBox1.Top + (Cursor.Position.Y - mouseDownPoint.Y);
69                 mouseDownPoint.X = Cursor.Position.X;
70                 mouseDownPoint.Y = Cursor.Position.Y;
71             }
72 
73         }

此方法實現的原理就是改變PictureBox的大小而改變圖像的大小，平移也是。

這個比較簡單的一種方法。

PictureBox中的圖片實現鼠標滑輪控制縮放和平移