自定义控件

最新推荐文章于 2025-08-14 17:31:00 发布

原创最新推荐文章于 2025-08-14 17:31:00 发布 · 477 阅读

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CC 4.0 BY-SA版权

文章标签：

#output #string #class #javascript #工具 #function

本文介绍了一个使用ASP.NET自定义的日期选择控件。该控件通过四个下拉列表分别选择年、月、起始日和结束日，并利用JavaScript进行联动更新。文章详细展示了控件的设计与实现过程。

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首先是以下这几项， // Attribute DefaultProperty指定组件的默认属性，ToolboxData指定当从IDE工具中的

        //工具箱中拖动自定义控件时为它生成的默认标记

          [DefaultProperty("Text"),

                    ToolboxData("<{0}:MyControl runat=server></{0}:MyControl>")]

上面这些是放在自定义控件的表头的。

这里放在属性那，当然可放可不放。
//Attribute Bindable指定属性是否通常用于绑定

//Category指定属性或事件将显示在可视化设计器中的类别

//DefalutValue用于指定属性的默认值

                    [Bindable(true),

                               Category("Appearance"),

                               DefaultValue("")]

以下是我写的一个自定义日期的控件，不是很完，但功能都有了，采用JS方式来联动。

using System;
using System.Data;
using System.Data.SqlClient;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.ComponentModel;
using System.Drawing;

namespace control
{

[ ToolboxData("<{0}:Class2 runat=server></{0}:Class2>")]
    public class Class2 : System.Web.UI.WebControls.WebControl
    {

public DropDownList ddlYear = new DropDownList();

public DropDownList ddlMonth = new DropDownList();

public DropDownList ddlFirstDay = new DropDownList();

public DropDownList ddlLastDay = new DropDownList();

public string sm = "";
public string sd = "";

  public Class2()
{
        ddlYear.Attributes.Add("onchange", "DateChange()");
        ddlMonth.Attributes.Add("onchange", "DateChange()");

        this.Controls.Add(ddlYear);
        this.Controls.Add(ddlMonth);
        this.Controls.Add(ddlFirstDay);
        this.Controls.Add(ddlLastDay);

}

        protected override void OnInit(EventArgs e)
        {

            this.ddlYear.Items.Clear();
            this.ddlMonth.Items.Clear();
            this.ddlFirstDay.Items.Clear();
            this.ddlLastDay.Items.Clear();
            //算出月份的
            int IsYear=int.Parse(DateTime.Now.Month.ToString());
            int IsYear2=int.Parse(DateTime.Now.Year.ToString());
            int IsDay=int.Parse(DateTime.Now.Day.ToString());

            for (int i = 2000; i <= 2050; i++)
            {
                ddlYear.Items.Add(new ListItem(i.ToString(), i.ToString()));
            }
            for (int i = 1; i <= 12; i++)
            {
                sm = strPadLeft(i.ToString());
                ddlMonth.Items.Add(new ListItem(sm, sm));
            }
           int[] monthofday=new int[12]{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

            if ((IsYear2 % 4 == 0 && IsYear2 % 100 != 0) || IsYear2 % 400 == 0)
            {
               monthofday[1]=29;
            }

            for (int i = 1; i <= monthofday[IsYear-1]; i++)
            {
                sd = strPadLeft(i.ToString());
                ddlFirstDay.Items.Add(new ListItem(sd, sd));
                ddlLastDay.Items.Add(new ListItem(sd, sd));
            }

            this.ddlYear.SelectedIndex = IsYear2-2000;
            this.ddlMonth.SelectedIndex = IsYear-1;
            ddlFirstDay.SelectedIndex = IsDay - 1;
            ddlLastDay.SelectedIndex = IsDay - 1;

        }
      // 填充的
        private string strPadLeft(string str)
        {
            return str.PadLeft(2, '0');
        }

        protected override void Render(HtmlTextWriter output)
        {
            AddAttributesToRender(output);

            output.AddAttribute(System.Web.UI.HtmlTextWriterAttribute.Cellpadding, "0", false);
            output.RenderBeginTag(HtmlTextWriterTag.Table);
            output.RenderBeginTag(HtmlTextWriterTag.Tr);
            output.RenderBeginTag(HtmlTextWriterTag.Td);

            ddlYear.RenderControl(output);
            output.Write("年");
            ddlMonth.RenderControl(output);
            output.Write("月");
            ddlFirstDay.RenderControl(output);
            output.Write("日--");
            ddlLastDay.RenderControl(output);
            output.Write("日");


          output.Write(@"<script language='javascript'>
function DateChange()
   {

var monthDays = new Array(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);

if((document.getElementById('ctl02').value%4==0 &&document.getElementById('ctl02').value%100!=0)||document.getElementById('ctl02').value%400==0    )
{
    monthDays[1]=29;
}

var monthofday= document.getElementById('ctl03').value;

monthofday=monthofday.substring(1,2);

var FirstDay=document.getElementById('ctl04');
FirstDay.length=0;

var LastDay=document.getElementById('ctl05');
LastDay.length=0;

for(i=1;i<=monthDays[monthofday-1];i++)
      {
       var optF=new Option(i,i);
       var optL=new Option(i,i);
       document.all.ctl04.options[i-1]=optF;
       document.all.ctl05.options[i-1]=optL;
      }

}
</script>");

          output.RenderEndTag();
          output.RenderEndTag();
          output.RenderEndTag();

        }

}