二级DropDownList控件源码

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二级DropDownList控件源码

将源码放于此，不过感觉并不是很满意。
有一个小问题，就是获取小类的值，因为控件中加入了一个功能，就是如果在初始时带入小类的值时，控件会自动将小类相应的选项选中，并带动大类的选项，这样就一个冲突：获取小类的值与初始小类的值带来的影响。

又开始忙了，再琢磨一下后修改。

源码如下：

using System.Text;

using System.Globalization;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.HtmlControls;

using System.Web.UI.Design;

using System;

using System.Drawing.Design;

using System.Drawing;

using System.Data;

using System.Collections;

using System.ComponentModel;

using System.ComponentModel.Design;

using System.Collections.Specialized;

namespace Flyangel.Component.WebUI

{

/// <summary>

/// AutoSelectDropList 的摘要说明。

/// </summary>

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

public class AutoSelectDropList : Control, INamingContainer,IPostBackEventHandler,IPostBackDataHandler

{

DropDownList _childdropdownlist = new DropDownList();

DropDownList _fatherdropdownlist = new DropDownList();

HtmlInputHidden _hideinput = new HtmlInputHidden();

#region 属性

数据源设置

所属FORM的ID名称

ChildID设置，用来进行子栏目的选择，并反向控制父栏的选择

数据字段设置

#endregion

public void RenderAtDesignTime()

{

if (!Page.IsPostBack)

{

CreateChildControls();

}

protected override void CreateChildControls()

{

Controls.Clear();

_hideinput.ID = "SCvalue";

_hideinput.Value = "0";

Controls.Add(_hideinput);

_fatherdropdownlist.ID = "fatherid";

_fatherdropdownlist.Attributes.Add("onChange","changelocation(document." + _formname + "." + this.ClientID + "_fatherid.options[document." + _formname + "." + this.ClientID + "_fatherid.selectedIndex].value)");

ListItem _newli = new ListItem();

_newli.Text = "一级栏目";

_newli.Value = "0";

_fatherdropdownlist.Items.Add(_newli);

if (SetSelectedChildID != "0")

{

GetFatherIDFormChildID();

}

int _tempfatheridstr = 0;

for(int i = 0; i<(DataSource.Tables[0].Rows.Count);i++)

{

ListItem _newlii = new ListItem();

_newlii.Value = DataSource.Tables[0].Rows[i][_fatherfieldid].ToString();

_newlii.Text = DataSource.Tables[0].Rows[i][_fatherfieldname].ToString();

_fatherdropdownlist.Items.Add(_newlii);

if (SetSelectedFatherID == DataSource.Tables[0].Rows[i][_fatherfieldid].ToString())

{

_tempfatheridstr = i+1;

}

Controls.Add(_fatherdropdownlist);

_fatherdropdownlist.SelectedIndex = _tempfatheridstr;

_childdropdownlist.ID = "childid";

_childdropdownlist.Attributes.Add("onChange","changechild(document." + _formname + "." + this.ClientID + "_childid.options[document." + _formname + "." + this.ClientID + "_childid.selectedIndex].value)");

int _tempchildidstr = 0;

if (SetSelectedChildID != "0")

{

DataView _temdv = new DataView(DataSource.Tables[1]);

string _filterstr = _parentid + " = " + SetSelectedFatherID;

_temdv.RowFilter = _filterstr;

for (int jj=0;jj<_temdv.Count;jj++)

{

ListItem _newlijai = new ListItem();

_newlijai.Value = _temdv[jj][_childfieldid].ToString();

_newlijai.Text = _temdv[jj][_childfieldname].ToString();

_childdropdownlist.Items.Add(_newlijai);

if (SetSelectedChildID == _temdv[jj][_childfieldid].ToString())

{

_tempchildidstr = jj;

}

else

{

ListItem _newliji = new ListItem();

_newliji.Text = "二级栏目";

_newliji.Value = "0";

_childdropdownlist.Items.Add(_newliji);

}

Controls.Add(_childdropdownlist);

_childdropdownlist.SelectedIndex = _tempchildidstr;

AddClientScript();

}

private void GetFatherIDFormChildID()

{

for(int j = 0; j<(DataSource.Tables[1].Rows.Count);j++)

{

if (SetSelectedChildID == DataSource.Tables[1].Rows[j][_childfieldid].ToString())

{

SetSelectedFatherID = DataSource.Tables[1].Rows[j][_parentid].ToString();

}

#region IPostBackEventHandler Implementation

/// <summary>

/// 实现<see cref="IPostBackEventHandler"/> 接口，使控件能够处理将窗体发送到服务器时引发的事件。

/// </summary>

/// <param name="args"></param>

public void RaisePostBackEvent(string args)

{

}

#endregion

IPostBackDataHandler Implementation

PageChanged Event

OnPageChanged Method

private void AddClientScript()

{

if(!Page.IsClientScriptBlockRegistered("clientScript"))

{

StringBuilder stringScript = new StringBuilder() ;

stringScript.Append(" ");

stringScript.Append("<script language="javascript"> ");

stringScript.Append("var onecount; ");

stringScript.Append("subcat = new Array(); ");

int _temi = DataSource.Tables[0].Rows.Count;

for(int i = 0; i<_temi;i++)

{

stringScript.Append("subcat[" + i + "] = new Array("二级栏目","" + DataSource.Tables[0].Rows[i][_fatherfieldid].ToString() + "","0"); ");

}

int _temj = DataSource.Tables[1].Rows.Count;

for(int j = 0; j<_temj;j++)

{

stringScript.Append("subcat[" + (_temi + j) + "] = new Array("" + DataSource.Tables[1].Rows[j][_childfieldname].ToString() + "","" + DataSource.Tables[1].Rows[j][_parentid].ToString() + "","" + DataSource.Tables[1].Rows[j][_childfieldid].ToString() + ""); ");

}

stringScript.Append("subcat[" + (_temj + _temi) + "] = new Array("二级栏目","0","0"); ");

stringScript.Append("onecount=" + (_temj + _temi + 1) + " ");

stringScript.Append(" ");

stringScript.Append("function changelocation(locationid) ");

stringScript.Append("{ ");

stringScript.Append(" document." + _formname + "." + this.ClientID + "_SCvalue.value = '0'; ");

stringScript.Append(" document." + _formname + "." + this.ClientID + "_childid.length = 0; ");

stringScript.Append(" var locationid=locationid; ");

stringScript.Append(" var i; ");

stringScript.Append(" for (i=0;i < onecount; i++) ");

stringScript.Append(" { ");

stringScript.Append(" if (subcat[i][1] == locationid) ");

stringScript.Append(" { ");

stringScript.Append(" document." + _formname + "." + this.ClientID + "_childid.options[document." + _formname + "." + this.ClientID + "_childid.length] = new Option(subcat[i][0], subcat[i][2]); ");

stringScript.Append(" } ");

stringScript.Append("} ");

stringScript.Append("function changechild(str) ");

stringScript.Append("{ ");