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The author:(作者)qqpublished in(发表于) 2014/7/11 9:23:43 C#教程:在GDI+中缩放图像
C#教程:在GDI+中缩放图像
在GDI+中缩放图像DrawImage为可重载方法,它的一种形式接收一个Bitmap对象和一个Rectangle结构。Rectangle矩形结构指定了绘图操作的目标,如果目标矩形的大小与原始图像的大小不同,原始图像将进行缩放,以适应目标矩形。示例缩放图像本示例中,当程序运行时,单击【缩放图像】按钮,在窗体中从左向右依次绘制3幅图像,其中第1幅图为原始图像的缩小形式,第2幅图与原始图像大小相同,第3幅图为原始图像的放大形式。示例运行结果如图1所示。图1 缩放图像Form1窗体中,在【缩放图像】按钮的Click事件中定义3个Rectangle矩形结构,然后调用Graphics类的DrawImage方法,在窗体中根据已经定义的3个Rectangle矩形结构依次绘制3幅图像。【缩放图像】按钮的Click事件代码如下:private void button1_Click(object sender, EventArgs e){Graphics graphics = this.CreateGraphics();Bitmap bitmap = new Bitmap("image.jpg");Rectangle rectangle1 = new Rectangle(10, 80, 100, 60);Rectangle rectangle2 = new Rectangle(130, 30, 283, 198);Rectangle rectangle3 = new Rectangle(435, 20, 300, 210);graphics.DrawImage(bitmap, rectangle1);graphics.DrawImage(bitmap, rectangle2);graphics.DrawImage(bitmap, rectangle3);}完整程序代码如下:★ ★★★★Form1.cs窗体代码文件完整程序代码★★★★★using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Text;using System.Windows.Forms;namespace _6_19{public partial class Form1 : Form{public Form1(){InitializeComponent();}private void button1_Click(object sender, EventArgs e){Graphics graphics = this.CreateGraphics();Bitmap bitmap = new Bitmap("image.jpg");Rectangle rectangle1 = new Rectangle(10, 80, 100, 60);Rectangle rectangle2 = new Rectangle(130, 30, 283, 198);Rectangle rectangle3 = new Rectangle(435, 20, 300, 210);graphics.DrawImage(bitmap, rectangle1);graphics.DrawImage(bitmap, rectangle2);graphics.DrawImage(bitmap, rectangle3);}}}★ ★★★★Form1.Designer.cs窗体设计文件完整程序代码★★★★★namespace _6_19{partial class Form1{/// /// 必需的设计器变量。/// private System.ComponentModel.IContainer components = null;/// /// 清理所有正在使用的资源。/// /// 如果应释放托管资源,为 true;否则为 false。protected override void Dispose(bool disposing){if (disposing && (components != null)){components.Dispose();}base.Dispose(disposing);}#region Windows 窗体设计器生成的代码/// /// 设计器支持所需的方法 - 不要/// 使用代码编辑器修改此方法的内容。/// private void InitializeComponent(){this.button1 = new System.Windows.Forms.Button();this.SuspendLayout();//// button1//this.button1.Location = new System.Drawing.Point(24, 12);this.button1.Name = "button1";this.button1.Size = new System.Drawing.Size(75, 23);this.button1.TabIndex = 0;this.button1.Text = "缩放图像";this.button1.UseVisualStyleBackColor = true;this.button1.Click += new System.EventHandler(this.button1_Click);//// Form1//this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;this.ClientSize = new System.Drawing.Size(746, 249);this.Controls.Add(this.button1);this.MaximizeBox = false;this.Name = "Form1";this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;this.Text = "Form1";this.ResumeLayout(false);}#endregionprivate System.Windows.Forms.Button button1;}}★ ★★★★Program.cs主程序文件完整程序代码★★★★★using System;using System.Collections.Generic;using System.Windows.Forms;namespace _6_19{static class Program{/// 赞 If you have any requirements, please contact webmaster。(如果有什么要求,请联系站长) QQ:154298438 QQ:417480759
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