C# 下载指定网页至本地源代码

【核心代码】

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

using System.Net;
using System.IO;

namespace Network
{
	/// <summary>
	/// Form1 的摘要说明。
	/// </summary>
	public class Form1 : System.Windows.Forms.Form
	{
		private System.Windows.Forms.Label label1;
		private System.Windows.Forms.TextBox textBox1;
		private System.Windows.Forms.Label label2;
		private System.Windows.Forms.TextBox textBox2;
		private System.Windows.Forms.Button button1;
		private System.Windows.Forms.Button button2;
		/// <summary>
		/// 必需的设计器变量。
		/// </summary>
		private System.ComponentModel.Container components = null;

		public Form1()
		{
			//
			// Windows 窗体设计器支持所必需的
			//
			InitializeComponent();

			//
			// TODO: 在 InitializeComponent 调用后添加任何构造函数代码
			//
		}

		/// <summary>
		/// 清理所有正在使用的资源。
		/// </summary>
		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
		/// <summary>
		/// 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。
		/// </summary>
		private void InitializeComponent()
		{
			this.label1 = new System.Windows.Forms.Label();
			this.textBox1 = new System.Windows.Forms.TextBox();
			this.label2 = new System.Windows.Forms.Label();
			this.textBox2 = new System.Windows.Forms.TextBox();
			this.button1 = new System.Windows.Forms.Button();
			this.button2 = new System.Windows.Forms.Button();
			this.SuspendLayout();
			// 
			// label1
			// 
			this.label1.Location = new System.Drawing.Point(32, 32);
			this.label1.Name = "label1";
			this.label1.Size = new System.Drawing.Size(72, 16);
			this.label1.TabIndex = 0;
			this.label1.Text = "网页地址：";
			// 
			// textBox1
			// 
			this.textBox1.Location = new System.Drawing.Point(96, 24);
			this.textBox1.Name = "textBox1";
			this.textBox1.Size = new System.Drawing.Size(192, 21);
			this.textBox1.TabIndex = 1;
			this.textBox1.Text = "";
			// 
			// label2
			// 
			this.label2.Location = new System.Drawing.Point(32, 64);
			this.label2.Name = "label2";
			this.label2.Size = new System.Drawing.Size(80, 16);
			this.label2.TabIndex = 2;
			this.label2.Text = "保存文件：";
			// 
			// textBox2
			// 
			this.textBox2.BackColor = System.Drawing.SystemColors.ActiveCaptionText;
			this.textBox2.Location = new System.Drawing.Point(96, 56);
			this.textBox2.Name = "textBox2";
			this.textBox2.Size = new System.Drawing.Size(192, 21);
			this.textBox2.TabIndex = 3;
			this.textBox2.Text = "";
			// 
			// button1
			// 
			this.button1.Location = new System.Drawing.Point(56, 96);
			this.button1.Name = "button1";
			this.button1.Size = new System.Drawing.Size(88, 23);
			this.button1.TabIndex = 4;
			this.button1.Text = "下载";
			this.button1.Click  = new System.EventHandler(this.button1_Click);
			// 
			// button2
			// 
			this.button2.Location = new System.Drawing.Point(184, 96);
			this.button2.Name = "button2";
			this.button2.Size = new System.Drawing.Size(88, 23);
			this.button2.TabIndex = 5;
			this.button2.Text = "关闭";
			this.button2.Click  = new System.EventHandler(this.button2_Click);
			// 
			// Form1
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
			this.ClientSize = new System.Drawing.Size(312, 142);
			this.Controls.Add(this.button2);
			this.Controls.Add(this.button1);
			this.Controls.Add(this.textBox2);
			this.Controls.Add(this.label2);
			this.Controls.Add(this.textBox1);
			this.Controls.Add(this.label1);
			this.MaximizeBox = false;
			this.Name = "Form1";
			this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
			this.Text = "演示下载网页";
			this.ResumeLayout(false);

		}
		#endregion

		/// <summary>
		/// 应用程序的主入口点。
		/// </summary>
		[STAThread]
		static void Main() 
		{
			Application.Run(new Form1());
		}

		private void button2_Click(object sender, System.EventArgs e)
		{//关闭程序
			this.Close();		
		}
		private void button1_Click(object sender, System.EventArgs e)
		{//下载网页
			if(this.textBox1.Text==""|this.textBox2.Text=="")
				return;
			string FileName=this.textBox2.Text.Trim();
			string URL=this.textBox1.Text.Trim();
			//加"http://"标志
			if (URL.IndexOf(@"http://")==-1 )
			{		
				URL=@"http://" URL;
			}
			HttpWebRequest MyRequest = (HttpWebRequest)WebRequest.Create(URL);
			//发送请求，获取响应
			HttpWebResponse MyResponse = (HttpWebResponse)MyRequest.GetResponse();
			Stream MyInStream = null;
			FileStream MyFileStream = null;
			try
			{
				MyInStream =MyResponse.GetResponseStream();
				long fileSizeInBytes = MyResponse.ContentLength;
				//创建文件流对象
				MyFileStream = new FileStream(FileName, FileMode.OpenOrCreate, FileAccess.Write);
				int length = 1024;
				byte[] buffer = new byte[1025];
				int bytesread = 0;
				string strtemp="";
				//从网络读取数据
				while((bytesread = MyInStream.Read(buffer, 0, length)) > 0)
				{	//把数据写入文件
					MyFileStream.Write(buffer, 0, bytesread);
					strtemp =System.Text.Encoding.Default.GetString(buffer,0,bytesread);
				}
				MessageBox.Show("下载网页成功！","信息提示",MessageBoxButtons.OK,MessageBoxIcon.Information); 	
			}
			catch(Exception Err)
			{
				MessageBox.Show("下载网页操作失败！错误是：" Err.Message,"信息提示",MessageBoxButtons.OK,MessageBoxIcon.Information); 				
			}
			finally
			{
				//关闭流
				if(MyInStream != null)
				{
					MyInStream.Close();
				}
				if(MyFileStream != null)
				{
					MyFileStream.Close();
				}
			}

		}
	}
}