Winform放大镜

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace Magnifier
{
public class Form1 : System.Windows.Forms.Form
{
private System.Windows.Forms.Button button1;
private System.Windows.Forms.OpenFileDialog openFileDialog1;
private System.ComponentModel.Container components = null;
private Image img = null;
private System.Windows.Forms.Panel panel1;
private System.Windows.Forms.Panel panel2;
private System.Windows.Forms.PictureBox pictureBox2;
private System.Windows.Forms.PictureBox pictureBox1;
private System.Windows.Forms.Label label1;
private int scale = 1;

public Form1()
{
InitializeComponent();
}

protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null) 
{
components.Dispose();
}
}
base.Dispose( disposing );
}

#region Windows 窗体设计器生成的代码
private void InitializeComponent()
{
this.button1 = new System.Windows.Forms.Button();
this.openFileDialog1 = new System.Windows.Forms.OpenFileDialog();
this.panel1 = new System.Windows.Forms.Panel();
this.panel2 = new System.Windows.Forms.Panel();
this.pictureBox2 = new System.Windows.Forms.PictureBox();
this.pictureBox1 = new System.Windows.Forms.PictureBox();
this.label1 = new System.Windows.Forms.Label();
this.panel1.SuspendLayout();
this.panel2.SuspendLayout();
this.SuspendLayout();
// 
// button1
// 
this.button1.Location = new System.Drawing.Point(416, 520);
this.button1.Name = "button1";
this.button1.Size = new System.Drawing.Size(96, 23);
this.button1.TabIndex = 1;
this.button1.Text = "浏览 >>";
this.button1.Click += new System.EventHandler(this.button1_Click);
// 
// panel1
// 
this.panel1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
this.panel1.Controls.Add(this.panel2);
this.panel1.Controls.Add(this.pictureBox1);
this.panel1.Location = new System.Drawing.Point(8, 8);
this.panel1.Name = "panel1";
this.panel1.Size = new System.Drawing.Size(504, 504);
this.panel1.TabIndex = 0;
// 
// panel2
// 
this.panel2.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
this.panel2.Controls.Add(this.pictureBox2);
this.panel2.Enabled = false;
this.panel2.Location = new System.Drawing.Point(50, 50);
this.panel2.Name = "panel2";
this.panel2.Size = new System.Drawing.Size(80, 80);
this.panel2.TabIndex = 1;
// 
// pictureBox2
// 
this.pictureBox2.Location = new System.Drawing.Point(0, 0);
this.pictureBox2.Name = "pictureBox2";
this.pictureBox2.Size = new System.Drawing.Size(80, 80);
this.pictureBox2.SizeMode = System.Windows.Forms.PictureBoxSizeMode.StretchImage;
this.pictureBox2.TabIndex = 0;
this.pictureBox2.TabStop = false;
// 
// pictureBox1
// 
this.pictureBox1.Cursor = System.Windows.Forms.Cursors.Cross;
this.pictureBox1.Location = new System.Drawing.Point(0, 0);
this.pictureBox1.Name = "pictureBox1";
this.pictureBox1.Size = new System.Drawing.Size(500, 500);
this.pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.StretchImage;
this.pictureBox1.TabIndex = 0;
this.pictureBox1.TabStop = false;
this.pictureBox1.Click += new System.EventHandler(this.pictureBox1_Click);
this.pictureBox1.DoubleClick += new System.EventHandler(this.pictureBox1_DoubleClick);
this.pictureBox1.MouseMove += new System.Windows.Forms.MouseEventHandler(this.pictureBox1_MouseMove);
// 
// label1
// 
this.label1.ForeColor = System.Drawing.Color.Blue;
this.label1.Location = new System.Drawing.Point(8, 520);
this.label1.Name = "label1";
this.label1.Size = new System.Drawing.Size(296, 24);
this.label1.TabIndex = 2;
this.label1.Text = "说明：鼠标单击可放大图片，双击可还原初始大小。";
this.label1.TextAlign = System.Drawing.ContentAlignment.MiddleLeft;
// 
// Form1
// 
this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
this.ClientSize = new System.Drawing.Size(522, 551);
this.Controls.Add(this.label1);
this.Controls.Add(this.button1);
this.Controls.Add(this.panel1);
this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
this.MaximizeBox = false;
this.Name = "Form1";
this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
this.Text = "图片放大镜 - 测试版 http://www.hbhmao.cn";
this.panel1.ResumeLayout(false);
this.panel2.ResumeLayout(false);
this.ResumeLayout(false);

}
#endregion

[STAThread]
static void Main() 
{
Application.Run(new Form1());
}

private void button1_Click(object sender, System.EventArgs e)
{
openFileDialog1.InitialDirectory = Application.StartupPath;
openFileDialog1.Filter = "图片文件|*.jpg;*.bmp;*.gif;*.jpeg;*.png";
if (openFileDialog1.ShowDialog() != System.Windows.Forms.DialogResult.OK)
{
return;
}
pictureBox1.Width = pictureBox1.Height = 500;
try
{
img = Image.FromFile(openFileDialog1.FileName);
if (img.Width < img.Height)
{
pictureBox1.Width = (int)((1.0 * img.Width / img.Height) * pictureBox1.Height);
}
else
{
pictureBox1.Height = (int)((1.0 * img.Height / img.Width) * pictureBox1.Width);
}
pictureBox1.Image = img;
pictureBox2.Width = img.Width * scale;
pictureBox2.Height = img.Height * scale;
pictureBox2.Image = img;
}
catch (OutOfMemoryException ee)
{
MessageBox.Show("文件类型不对"+ee);
}
catch (Exception ee)
{
MessageBox.Show("不知名错误"+ee);
}
}

private void pictureBox1_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
{
if (img != null)
{
int left = (int)(e.X * (1.0 * img.Width/pictureBox1.Width)*scale);
int top = (int)(e.Y * (1.0 * img.Height/pictureBox1.Height)*scale);

left -= panel2.Width/2;
top -= panel2.Height/2;

pictureBox2.Left = -left;
pictureBox2.Top = -top;

pictureBox1.Refresh();
}
panel2.Top = e.Y - panel2.Height / 2;
panel2.Left = e.X - panel2.Width / 2;
}

private void pictureBox1_Click(object sender, System.EventArgs e)
{
if (img == null || scale > 10)
{
return;
}
scale++;
panel2.Width += 10;
panel2.Height += 10;
pictureBox2.Width = img.Width * scale;
pictureBox2.Height = img.Height * scale;
}

private void pictureBox1_DoubleClick(object sender, System.EventArgs e)
{
if (img == null)
{
return;
}
scale = 1;
panel2.Width = 80;
panel2.Height = 80;
pictureBox2.Width = img.Width * scale;
pictureBox2.Height = img.Height * scale;
}

}
}

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      转自：http://www.cnblogs.com/jyshi/