c# multi-ply download ui

first neet add an user control "DownloadBar":

/*

• Created by SharpDevelop.
• User: gwang
• Date: 2016/8/25
• Time: 14:01
• To change this template use Tools | Options | Coding | Edit Standard Headers.
  */
  using System;
  using System.ComponentModel;
  using System.Drawing;
  using System.Windows.Forms;

namespace testHttp
{
///

/// Description of DownloadBar.
///

public partial class DownloadBar : UserControl
{
public DownloadBar()
{
//
// The InitializeComponent() call is required for Windows Forms designer support.
//
InitializeComponent();
Anchor=AnchorStyles.Left|AnchorStyles.Right;
// Width=Parent.Width -40;
Height=65;

		//
		// TODO: Add constructor code after the InitializeComponent() call.
		//
	}
	
	public DownloadBar(DownLoadInfo info)
	{
		//
		// The InitializeComponent() call is required for Windows Forms designer support.
		//
		InitializeComponent();
		MinimumSize= new Size(126,66);
		this.info=info;
		btn1.Text=""+info.title +info.uid;
		btn1.Visible=false;
	    lb1.Visible=true ;
	    
		if (info.ProgressPercentage<100){
		
			lb1.Visible=true;
			lb1.Text=info.ProgressPercentage+"%";
		
		}
	
		t = new Timer();
     	t.Tick+=t_tick;
		t.Start ();
	}
	
	protected override void OnLoad(EventArgs e)
	{
		

		base.OnLoad(e);	
		//Anchor=AnchorStyles.Left|AnchorStyles.Right;
	   // this.Size = new System.Drawing.Size(274, 65);
	      this.Size = new System.Drawing.Size(Parent.Width-20, 65);
		this.ResumeLayout(false);
		
		
	}
	
	
	Timer t;
	DownLoadInfo   info;
	
	void t_tick(object sender, EventArgs e){
		
		if(info.ProgressPercentage>=100 || info.isCompleted )
		{
			//lb1.Visible=false;
			t.Stop();
		    btn1.Visible=true ;
		    lb1.Visible=false;
		}
	
		lb1.Text=info.ProgressPercentage+"%";
		lb1.Width=(int )( Width* ((double )info.ProgressPercentage * 0.01d));
		
		
	
	}
	void Btn1Click(object sender, EventArgs e)
	{
		MessageBox.Show(info.title );
	}
	
	
}

}

---------partial class for ui InitializeComponent------------------------

/*

• Created by SharpDevelop.

• User: gwang

• Date: 2016/8/25

• Time: 14:01

• To change this template use Tools | Options | Coding | Edit Standard Headers.
  */
  namespace testHttp
  {
  partial class DownloadBar
  {
  ///

  
  /// Designer variable used to keep track of non-visual components.
  ///
  
  private System.ComponentModel.IContainer components = null;
  private System.Windows.Forms.Label lb1;
  private System.Windows.Forms.Button btn1;

   /// <summary>
   /// Disposes resources used by the control.
   /// </summary>
   /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
   protected override void Dispose(bool disposing)
   {
   	if (disposing) {
   		if (components != null) {
   			components.Dispose();
   		}
   	}
   	base.Dispose(disposing);
   }
   
   /// <summary>
   /// This method is required for Windows Forms designer support.
   /// Do not change the method contents inside the source code editor. The Forms designer might
   /// not be able to load this method if it was changed manually.
   /// </summary>
   private void InitializeComponent()
   {
   	this.lb1 = new System.Windows.Forms.Label();
   	this.btn1 = new System.Windows.Forms.Button();
   	this.SuspendLayout();
   	// 
   	// lb1
   	// 
   	this.lb1.BackColor = System.Drawing.Color.DodgerBlue;
   	this.lb1.Dock = System.Windows.Forms.DockStyle.Left;
   	this.lb1.Location = new System.Drawing.Point(0, 0);
   	this.lb1.Name = "lb1";
   	this.lb1.Size = new System.Drawing.Size(55, 65);
   	this.lb1.TabIndex = 0;
   	this.lb1.Text = "10%";
   	this.lb1.TextAlign = System.Drawing.ContentAlignment.MiddleCenter;
   	// 
   	// btn1
   	// 
   	this.btn1.Dock = System.Windows.Forms.DockStyle.Fill;
   	this.btn1.Location = new System.Drawing.Point(0, 0);
   	this.btn1.Name = "btn1";
   	this.btn1.Size = new System.Drawing.Size(274, 65);
   	this.btn1.TabIndex = 1;
   	this.btn1.UseVisualStyleBackColor = true;
   	this.btn1.Click += new System.EventHandler(this.Btn1Click);
   	// 
   	// DownloadBar
   	// 
   	this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
   	this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
   	this.BackColor = System.Drawing.Color.LightSteelBlue;
   	this.Controls.Add(this.lb1);
   	this.Controls.Add(this.btn1);
   	this.Name = "DownloadBar";
   	this.Size = new System.Drawing.Size(274, 65);
   	this.ResumeLayout(false);
  
   }
  

  }
  }

---

2 main ui form code behind "FrmDownload":

/*

• Created by SharpDevelop.
• User: gwang
• Date: 2016/8/25
• Time: 14:34
• To change this template use Tools | Options | Coding | Edit Standard Headers.
  */
  using System;
  using System.Drawing;
  using System.Windows.Forms;

namespace testHttp
{
///

/// Description of FrmDownload.
///

public partial class FrmDownload : Form
{
public FrmDownload()
{
//
// The InitializeComponent() call is required for Windows Forms designer support.
//
InitializeComponent();

		//
		// TODO: Add constructor code after the InitializeComponent() call.
		//
	}
	
	
	int uid=1;
	
	void Button1Click(object sender, EventArgs e)
	{
		DownLoadInfo info = new DownLoadInfo();
		info.url="http://sw.bos.baidu.com/sw-search-sp/av_aladdin/a997f8c5c22/rj_hb1174.exe";
		info.title="test it "+ uid ;
		info.uid=""+uid ;
		HttpUtils.downloadFile(info);
		uid++;
		
		this.flowLayoutPanel1.Controls.Add(new DownloadBar(info));
		Text="there "+ this.flowLayoutPanel1.Controls.Count  +"  downloading.........";
	}
	
	
}

}

oh... first need define util class "HttpUtils"

/*

• Created by SharpDevelop.

• User: gwang

• Date: 2016/8/24

• Time: 17:23

• To change this template use Tools | Options | Coding | Edit Standard Headers.
  */
  using System;
  using System.Net;
  using System.ComponentModel;
  using System.Collections;
  using System.Collections.Generic;
  using System.Linq;
  namespace testHttp
  {
  ///

  
  /// Description of HttpUtils.
  ///
  
  public class HttpUtils
  {
  public HttpUtils()
  {

   }
   
  
   public static List<DownLoadInfo> listDownloadInfo= new List<DownLoadInfo>();
   
   public static void downloadFile(DownLoadInfo info){
   	
   	if(listDownloadInfo.Count (n=> n.uid==info.uid )>0)
   	   { 
   	   	
   	   	return;
   	   }
   	
   	listDownloadInfo.Add(info);
   	WebClient 	wc=new WebClient();
   	wc.DownloadProgressChanged+= wc_DownloadProgressChanged;
   	wc.DownloadDataCompleted+=wc_DownloadDataCompleted;
   	
   	//wc.DownloadStringAsync(new Uri("https://jirafnd.dev.activenetwork.com/browse/HYTEK-274",UriKind.Absolute ),info);
       wc.DownloadDataAsync(new Uri(info.url ,UriKind.Absolute ),info);
  
   }
  
   private static  void wc_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e){
   	
   	(e.UserState as DownLoadInfo ).ProgressPercentage=  e.ProgressPercentage;
   
   }
   
   
   private static  void wc_DownloadDataCompleted(object sender, DownloadDataCompletedEventArgs e){
   	
   	(e.UserState as DownLoadInfo ).isCompleted =( e.Error==null) ;
   
   }
  

  }

  // this for basic info class
  public class DownLoadInfo{

   public string title{get;set;}
   public string  url{get;set;}
   public string uid{get;set;}
   public int  ProgressPercentage{ get;set;}
   public bool isCompleted{get;set;}
  

  }

}