winform 分页控件

上博客园也有2个月的时间了,一直都只是看别人写的帖子。今天终于注册了个ID。

这次把我写的一个分页控件贴上来。前阵子写了一个winform的数据库管理程序,用一个dataGrid显示数据库表中的所有内容,后来发现当数据库中的条目增多的时候,程序运行速度明显下降,系统占用内存也很大,决定对dataGrid做个分页,每次只取出要显示页的内容。上网搜了一下,没有找到我需要的,于是自己写了一个分页控件。

程序很简单,用的时候需要提供pageCount(页数),pageShow(显示的页数),currPage(当前页号)
控件提供一个自定义的事件LnkLblClicked,当用户点击页面链接的时候就会触发这个事件。下面是程序的源码。

 

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

namespace ActiveButton
{
    
/// <summary>
    
/// Summary description for PageControl.
    
/// </summary>

    public class PageControl : System.Windows.Forms.UserControl
    
{
        
/// <summary> 
        
/// Required designer variable.
        
/// </summary>

        private int pageCount;
        
private int currPage;
    
//    private int pageSize;
        private int pageShow;
        
private int xDistance;
        
private bool bolPrev;
        
private bool bolNext;
        
private int start, end;

        
private EventHandler lnkLblClicked;

        
public event EventHandler LnkLblClicked
        
{
            add
{lnkLblClicked += value;}
            remove
{lnkLblClicked -= value;}
        }

        
protected virtual void OnLnkLblClicked(EventArgs e)
        
{
            
if (lnkLblClicked != null)
                lnkLblClicked(
this,e);                
        }


        
Field
        

        
private System.ComponentModel.Container components = null;

        
public PageControl()
        
{
            
// This call is required by the Windows.Forms Form Designer.
            InitializeComponent();

            
// TODO: Add any initialization after the InitializeComponent call

        }

        
public PageControl(int pageCount,int pageSize,int pageShow):this()
        
{
            
this.pageCount = pageCount;
        
//    this.pageSize = pageSize;
            this.pageShow = pageShow;
        }


        
/// <summary> 
        
/// Clean up any resources being used.
        
/// </summary>

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

            }

            
base.Dispose( disposing );
        }


        
Component Designer generated code

        
private void PageControl_Load(object sender, System.EventArgs e)
        
{
            xDistance 
= 0;
            bolPrev 
= pageCount > pageShow;
        
//    currPage = pageCount;
            end = pageCount;
            start 
= Math.Max(1,end - pageShow + 1);
            DrawControl();
        }

        
private void DrawControl()
        
{
            
this.Controls.Clear();
            System.Windows.Forms.Label lblPageCount 
= new Label();
            lblPageCount.Text 
= "" + pageCount + "";
            
this.AddControl(lblPageCount,new Point(8,8),new Size(40,16));
            
int x = lblPageCount.Bounds.Right;
            
int y = lblPageCount.Location.Y;
            System.Windows.Forms.Control currCtl 
= lblPageCount;

            
//calculate page start and end
            int pageShowCount = Math.Min(pageCount,pageShow);
//            start = Math.Max(1,currPage - pageShow/2);
//            end = start + pageShowCount -1;
//            if (pageCount - currPage < pageShow/2)
//            {
//                end = pageCount;
//                start = pageCount - pageShowCount + 1;
//            }
            bolPrev = start != 1;
            bolNext 
= end != pageCount;

            
if (bolPrev)
            
{//add Linklabel "prev"
                System.Windows.Forms.LinkLabel lblPrev = new LinkLabel();
                lblPrev.Text 
= "前一页";
                x 
+= xDistance;
                ((LinkLabel)lblPrev).LinkClicked 
+= new LinkLabelLinkClickedEventHandler(lblCtl_Clicked);
                
this.AddControl(lblPrev,new Point(x,y),new Size(4516));
                currCtl 
= lblPrev;
            }

            
            
for (int i = start; i <= end; i ++)
            
{// add linklabel "page"
                x = currCtl.Bounds.Right;
                System.Windows.Forms.Control lblCtl 
= null;
                
if ( i == currPage)
                    lblCtl 
= new System.Windows.Forms.Label();
                
else
                
{
                    lblCtl 
= new System.Windows.Forms.LinkLabel();
                    ((LinkLabel)lblCtl).LinkClicked 
+= new LinkLabelLinkClickedEventHandler(lblCtl_Clicked);
                }

                lblCtl.Text 
= i.ToString();
                x 
+= xDistance;
                
this.AddControl(lblCtl,new Point(x,y),new Size(1016));
                currCtl 
= lblCtl;
            }

            
if (bolNext)
            
{// add linklabel "next"
                System.Windows.Forms.LinkLabel lblNext = new LinkLabel();
                lblNext.Text 
= "后一页";
                x 
= currCtl.Bounds.Right;
                x 
+= xDistance;
                ((LinkLabel)lblNext).LinkClicked 
+= new LinkLabelLinkClickedEventHandler(lblCtl_Clicked);
                
this.AddControl(lblNext,new Point(x,y),new Size(4516));
            }

        }

        
private void AddControl(Control ctlObj,Point point,Size size)
        
{
            ctlObj.Anchor 
= ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) 
                
| System.Windows.Forms.AnchorStyles.Left)));
            ctlObj.Location 
= point;
            
int x = ctlObj.Text.Length * 10;
            
if (ctlObj.Text.IndexOf(""> 0 )
            
{
                
if (ctlObj.Text.IndexOf("">= 0)
                    x 
+= 10;
                
else
                    x 
*= 2;
            }

            ctlObj.Size 
= new Size(x,16);
            
this.Controls.Add(ctlObj);
        }


        
private void lblCtl_Clicked(object sender, System.Windows.Forms.LinkLabelLinkClickedEventArgs e)
        
{
            
if (sender is LinkLabel)
            
{
                
try
                
{
                    
string lblText = ((LinkLabel)sender).Text;
                    
if (lblText == "前一页")
                    
{
                        end 
= start -1;
                        start 
= Math.Max(1,end - pageShow + 1);
                        currPage 
= end;
                    }

                    
else if (lblText == "后一页")
                    
{
                        start 
= end + 1;
                        end 
= Math.Min(pageCount,start + pageShow -1);
                        currPage 
= end;
                    }

                    
else
                    
{
                        
int page = Convert.ToInt32(lblText);
                        currPage 
= page;
                    }

                    
this.DrawControl();
                    
this.OnLnkLblClicked(e);
                }

                
catch{}
            }

        }


        
public void ReDraw()
        
{
            bolPrev 
= pageCount > pageShow;
        
//    currPage = pageCount;
            end = pageCount;
            start 
= Math.Max(1,end - pageShow + 1);
            
this.DrawControl();
            
this.OnLnkLblClicked(null);
        }

    }

}

 

 

posted on 2004-08-20 15:41  flood  阅读(11539)  评论(6编辑  收藏  举报

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