[报到] 发布个自己修改的联动下拉菜单 (无限级、数据库、初始值.)-白红宇

[报到] 发布个自己修改的联动下拉菜单 (无限级、数据库、初始值.)

阅读量：6084 次

发布时间：2019-06-20

本文共 7944 字，大约阅读时间需要 26 分钟。

因为网站需要，在网上找了很多都不满足需要，所以找了一个代码自己修改，然后再封装成自定义控件。自己觉得还比较满意，希望有人需要可以供查询。

控件的特点：

1、理论上支持无限级，不过我目前只做到4级，需要的人可自行拓展，很简单的：）。

2、是数据库版的，也可以很方便的改为XML版本。

3、加载速度比较快。

4、可以设置初始值（很多没这个功能哦）。

5、可以设置是否必须选择。

6、可以设置是否必须选择到最后一级。

7、等你去发现……

================== 控件代码 =====================

using System;

using System.Data;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.ComponentModel;

namespace StsProject.CustomControl

{

[DefaultProperty("Text"),

Designer(typeof(CompanyIndustryDesigner)),

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

public class CompanyIndustryer : System.Web.UI.WebControls.WebControl,INamingContainer

{

private bool _ismust = false;

private bool _musttoend = false;

[Bindable(true),

Category("Behavior"),

DefaultValue(false),

Description("是否必须填写")]

public bool IsMust

{

get{return _ismust;}

set{_ismust=value;}

}

[Bindable(true),

Category("Behavior"),

DefaultValue(false),

Description("是否必须选择到最后一级")]

public bool MustToEnd

{

get{return _musttoend;}

set{_musttoend=value;}

}

[Bindable(true),

Category("Behavior"),

DefaultValue(""),

Description("行业编号")]

public string IndustryValue

{

set

{

this.EnsureChildControls();

((TextBox)Controls[0]).Text = value;

}

get

{

this.EnsureChildControls();

return ((TextBox)Controls[0]).Text;

}

protected override void CreateChildControls()

{

base.CreateChildControls ();

TextBox txtIndustryValue = new TextBox();

txtIndustryValue.ID = "IndustryValue";

txtIndustryValue.Width = 0;

this.Controls.Add(txtIndustryValue);

DropDownList dropIndustry1 = new DropDownList();

dropIndustry1.ID = "dropIndustry1";

this.Controls.Add(dropIndustry1);

DropDownList dropIndustry2 = new DropDownList();

dropIndustry2.ID = "dropIndustry2";

this.Controls.Add(dropIndustry2);

DropDownList dropIndustry3 = new DropDownList();

dropIndustry3.ID = "dropIndustry3";

this.Controls.Add(dropIndustry3);

DropDownList dropIndustry4 = new DropDownList();

dropIndustry4.ID = "dropIndustry4";

dropIndustry4.Width = 0;

this.Controls.Add(dropIndustry4);

TextBox txtToEnd = new TextBox();

txtToEnd.ID = "txtIfEnd";

txtToEnd.Width = 0;

this.Controls.Add(txtToEnd);

dropIndustry1.Attributes.Add("ChildSelectName", dropIndustry2.ClientID);

dropIndustry1.Attributes.Add("style","display:none");

dropIndustry2.Attributes.Add("ChildSelectName", dropIndustry3.ClientID);

dropIndustry2.Attributes.Add("FatherSelectName", dropIndustry1.ClientID);

dropIndustry2.Attributes.Add("style","display:none");

dropIndustry3.Attributes.Add("ChildSelectName", dropIndustry4.ClientID);

dropIndustry3.Attributes.Add("FatherSelectName", dropIndustry2.ClientID);

dropIndustry3.Attributes.Add("style","display:none");

if (_ismust)

{

RequiredFieldValidator valrIndustry = new RequiredFieldValidator();

valrIndustry.ControlToValidate = txtIndustryValue.ID;

valrIndustry.ErrorMessage = "<<请选择分类";

valrIndustry.Display = ValidatorDisplay.Dynamic;

this.Controls.Add(valrIndustry);

}

if (_musttoend)

{

RegularExpressionValidator valeIndustry = new RegularExpressionValidator();

valeIndustry.ControlToValidate = txtToEnd.ID;

valeIndustry.ErrorMessage = "<<必须选择到最后一级";

valeIndustry.Display = ValidatorDisplay.Dynamic;

valeIndustry.ValidationExpression = "Yes|DD";

this.Controls.Add(valeIndustry);

}

string strScript = @"<script>

var m_oXMLDoc = new ActiveXObject(""Microsoft.XMLDOM"");

var m_sBaseSrc = ""/GetIndustry.aspx?TopID="";

function BindSelect( strXMLSrc , objSelectName, defaultVal)

{

m_oXMLDoc.async = true;

m_oXMLDoc.onreadystatechange = Function( ""fnLoadComplete('"" + objSelectName + ""', '"" + defaultVal + ""');"" );

m_oXMLDoc.load( strXMLSrc );

}

function fnLoadComplete(objSelectName, defaultVal)

{

var objSelect = document.all[objSelectName];

var aryXMLNodes;

var node;

if (objSelect == null)

return;

try

{

var iReadyState = m_oXMLDoc.readyState;

}

catch(e)

{

return;

}

if( iReadyState != 4 ) return;

if( m_oXMLDoc != null && m_oXMLDoc.xml != """" )

{

objSelect.length = 0;

aryXMLNodes = m_oXMLDoc.documentElement.selectNodes(""//IndustryList/Table"");

objSelect.options[0] = new Option(""==请选择=="","""");

var m=0;

for (var i=0; i < aryXMLNodes.length; i++)

{

node = aryXMLNodes[i];

objSelect.options[i+1] = new Option(aryXMLNodes[i].childNodes.item(1).text, aryXMLNodes[i].childNodes.item(0).text);

m=m+1;

}

if (m!=0)

{

objSelect.style.display='';

}

else

{

objSelect.style.display='none';

}

if (defaultVal != null && defaultVal != """" && objSelect.length > 1)

{

SetSelectedValue(objSelect, defaultVal)

}

if(objSelect.ChildSelectName != null)

{

objSelect.onchange = Function( ""BindSelect(m_sBaseSrc+this.options[this.selectedIndex].value, '""+objSelect.ChildSelectName+""', '""+defaultVal+""');SetTheValue(this);"" );

objSelect.fireEvent(""onchange"");

}

else

{

objSelect.onchange = Function( ""var val = this.options[this.selectedIndex].value;if(val!='')document.all."+ txtIndustryValue.ClientID ;"" );

}

function SetTheValue(obj)

{

//这个地方代码很多，主要是修复我找的代码的一个缺陷，就是选择了一级后，然后再选则该级的最上一个选项(--请选择--)后，取到的值不变

var val = obj.value;

if(val!='')