摘要：
使用ascx的目的是提高某些函数的重用性。我将通过源代码简单地讨论其参数的输入和输出。让我们以省市区三级联动运动为例。vs2005中ascx页面的代码：codeascx背景代码：CodepublicpartialclassUserControl_ ProvinceAndCityAndDistrict:System.Web.UI。UserControl｛/////////选择iD//////protectedstring_districtValue；[Bindable，Category，DefaultValue（“”）]publicstringdistrictValue｛get｛return_districtValue；｝设置｛_districtValue=value；｝｝受保护字符串_城市值；[Bindable，Category，DefaultValue（“”）]publicstringcityValue｛get｛return_cityValue；｝设置｛_cityValue=值；｝｝受保护字符串_ provinceValue；[Bindable，Category，DefaultValue（“”）]publicstringProvisionValue｛get｛return_proviceValue；｝设置｛_proviceValue=value；｝｝privatevoisetValue（）｛if（_proviceValue！
使用ascx目的就是为了提高某部分功能的重复利用，我简单通过源代码说一下对它的参数的输入和数出。
我们以省市区三级连动为例子。
vs2005下ascx页面的代码：
Code
<table width="100%" border="0" cellpadding="0" cellspacing="0"> <tr> <td> <asp:DropDownList id="ddlProvince" runat="server" Width="100px" AutoPostBack="True" OnSelectedIndexChanged="ddlProvince_SelectedIndexChanged"> </asp:DropDownList> <asp:UpdatePanel ID="UpdatePanel1" runat="server" RenderMode="Inline"> <ContentTemplate> <asp:DropDownList id="ddlCity" runat="server" Width="100px" AutoPostBack="True" OnSelectedIndexChanged="ddlCity_SelectedIndexChanged"> </asp:DropDownList> </ContentTemplate> <Triggers> <asp:AsyncPostBackTrigger ControlID="ddlProvince" EventName="SelectedIndexChanged" /> </Triggers> </asp:UpdatePanel> <asp:UpdatePanel ID="UpdatePanel2" runat="server" RenderMode="Inline"> <ContentTemplate> <asp:DropDownList id="ddlDistrict" runat="server" Width="100px"> </asp:DropDownList> </ContentTemplate> <Triggers> <asp:AsyncPostBackTrigger ControlID="ddlCity" EventName="SelectedIndexChanged" /> </Triggers> </asp:UpdatePanel> </td> </tr> </table>ascx后台代码：
Codepublic partial class UserControl_ProvinceAndCityAndDistrict : System.Web.UI.UserControl
{
///// <summary>
///// 选择区域的iD
///// </summary>
protected string _districtValue;
[Bindable(true), Category("Appearance"), DefaultValue("")]
public string districtValue
{
get { return _districtValue; }
set { _districtValue = value; }
}
protected string _cityValue;
[Bindable(true), Category("Appearance"), DefaultValue("")]
public string cityValue
{
get { return _cityValue; }
set { _cityValue = value; }
}
protected string _provinceValue;
[Bindable(true), Category("Appearance"), DefaultValue("")]
public string provinceValue
{
get { return _provinceValue; }
set { _provinceValue = value; }
}
private void setValue()
{
if (_provinceValue != string.Empty)
{
this.ddlProvince.SelectedItem.Text = _provinceValue;
}
if (_cityValue != string.Empty)
{
this.ddlCity.SelectedItem.Text = _cityValue;
}
if (_districtValue != string.Empty)
{
this.ddlDistrict.SelectedItem.Text = _districtValue;
}
}
public string getValue()
{
return this.ddlProvince.SelectedItem.Text + "," + ddlCity.SelectedItem.Text + "," + ddlDistrict.SelectedItem.Text;
}
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
setProvince();
this.ddlProvince.SelectedIndex = 0;
setCity(Convert.ToInt32(this.ddlProvince.SelectedValue));
this.ddlCity.SelectedIndex = 0;
setDistrict(Convert.ToInt32(this.ddlCity.SelectedValue));
setValue();
}
}
private void setProvince()
{
CallCenter.BLL.sys_Province province = new CallCenter.BLL.sys_Province();
DataSet ds = province.getProvinceList();
this.ddlProvince.DataSource = ds.Tables[0];
this.ddlProvince.DataValueField = "provinceid";
this.ddlProvince.DataTextField = "provincename";
this.ddlProvince.DataBind();
}
private void setCity(int provinceId)
{
CallCenter.BLL.sys_City city = new CallCenter.BLL.sys_City();
DataSet ds = city.getCityList(provinceId);
this.ddlCity.DataSource = ds.Tables[0];
this.ddlCity.DataValueField = "cityid";
this.ddlCity.DataTextField = "cityName";
this.ddlCity.DataBind();
}
private void setDistrict(int cityId)
{
CallCenter.BLL.sys_District district = new CallCenter.BLL.sys_District();
DataSet ds = district.getDistrictList(cityId);
this.ddlDistrict.DataSource = ds.Tables[0];
this.ddlDistrict.DataValueField = "districtid";
this.ddlDistrict.DataTextField = "districtname";
this.ddlDistrict.DataBind();
}
protected void ddlProvince_SelectedIndexChanged(object sender, EventArgs e)
{
setCity(Convert.ToInt32(this.ddlProvince.SelectedValue));
this.ddlCity.SelectedIndex = 0;
setDistrict(Convert.ToInt32(this.ddlCity.SelectedValue));
}
protected void ddlCity_SelectedIndexChanged(object sender, EventArgs e)
{
setDistrict(Convert.ToInt32(this.ddlCity.SelectedValue));
}
}
使用aspx页面的后台调用部分代码：
如何传入参数，对于ascx的参数一般通过自定义页面属性来实现的。在ascx的页面我定义了几个属性
provincevalue，cityvalue，districtvalue，把你所需要传入的参数通过下面的方式给它就可以了，至于出入后你需要怎么处理你就自己操作了，上面有我的简单处理方式。
Codestring[] strAddress=ds.Tables[0].Rows[i]["value"].ToString().Split(',');
this.ProvinceAndCityAndDistrict1.provinceValue = strAddress[0];
this.ProvinceAndCityAndDistrict1.cityValue = strAddress[1];
this.ProvinceAndCityAndDistrict1.districtValue = strAddress[2];
从ascx获取输出的东西的话，我目前采用的是通过公共函数调用来实现的
比如在对aspx页面的信息进行保存的时候，我要获取到当前所选择的省市区信息，我是通过方法getValue()来获取返回的字符窜的，你可以根据自己的需要来定义适当的方法。
this.ProvinceAndCityAndDistrict1.getValue();
希望我通过简单的举例说明能够帮助大家对ascx的使用有个初步简单的了解。有好的方法相互交流，共同进步！