C# 后台三级联动

1，DropDownList属性AutoPostBack="True"

2，放在UpdatePanel内，用UpdatePanel后，只对UpdatePanel内的控件做数据绑定，不会对UpdatePanel外的control做操作（包括事件也不会触发）

3，一个UserControl占用页面的一行。

4，每个UserControl在页面上都是一个Div，可以用Div属性设置大小

5，Control之间的间距可以用<table>来接近：<table cellpadding="0"; cellspacing="0"; ><td style="padding-left:0px" >

 

6，联动可以用JavaScript完成，但是不能做成UserControl，因为JavaScript上要getElementsByID

问题不明，JavaScript不熟悉

 

<table cellpadding="0"; cellspacing="0"; style=" border:-1 none">
<tr style=" letter-spacing: 0px">
<td style="padding-left: 0px">
Dept. / Group / Section / Unit&nbsp;<asp:DropDownList ID="ddlDept" runat="server"
AutoPostBack="True" OnSelectedIndexChanged="ddlDept_SelectedIndexChanged" Width="105px">
<asp:ListItem Value="0">-select dept-</asp:ListItem>
</asp:DropDownList>
</td>
<td style="padding-left:0px">
<asp:DropDownList ID="ddlGroup" runat="server" AutoPostBack="True" OnSelectedIndexChanged="ddlGroup_SelectedIndexChanged"
Width="105px">
<asp:ListItem Value="0">-select group-</asp:ListItem>
</asp:DropDownList>
</td>
<td style=" padding-left:0px">
<asp:DropDownList ID="ddlSection" runat="server" AutoPostBack="True" OnSelectedIndexChanged="ddlSection_SelectedIndexChanged"
Width="105px">
<asp:ListItem Value="0">-select section-</asp:ListItem>
</asp:DropDownList>
</td>
<td style=" padding-left:0px">
<asp:DropDownList ID="ddlUnit" runat="server" AutoPostBack="True" Width="105px">
<asp:ListItem Value="0">-select unit-</asp:ListItem>
</asp:DropDownList>
</td>
</tr>
</table>

 

 

#region 属性
private bool isEnable = true;

public bool IsEnable
{
get { return isEnable; }
set { isEnable = value; }
}
private bool isDeptVisible = true;

public bool IsDeptVisible
{
get { return isDeptVisible; }
set { isDeptVisible = value; }
}
private bool isGroupVisible = true;

public bool IsGroupVisible
{
get { return isGroupVisible; }
set { isGroupVisible = value; }
}
private bool isSectionVisible = true;

public bool IsSectionVisible
{
get { return isSectionVisible; }
set { isSectionVisible = value; }
}
private bool isUnitVisible = true;

public bool IsUnitVisible
{
get { return isUnitVisible; }
set { isUnitVisible = value; }
}

public string dept_id
{
get
{
return ddlDept.SelectedItem.Value.ToString();
}
set
{
if (value is string)
{
ddlDept.SelectedItem.Value = value;
ddlDept_SelectedIndexChanged(null, null);
}
}
}
public string group_id
{
get
{
return ddlGroup.SelectedItem.Value.ToString();
}
set
{
if (value is string)
{
ddlGroup.SelectedItem.Value = value;
ddlGroup_SelectedIndexChanged(null, null);
}
}
}
public string section_id
{
get
{
return ddlSection.SelectedItem.Value.ToString();
}
set
{
if (value is string)
{
ddlSection.SelectedItem.Value = value;
ddlSection_SelectedIndexChanged(null, null);
}
}
}
public string unit_id
{
get
{
return ddlUnit.SelectedItem.Value.ToString();
}
set
{
if (value is string)
{
ddlUnit.SelectedItem.Value = value;
}
}
}
public DataTable dtResult(string dbTable)
{
DataTable dt = new DataTable();
return dt;
}
#endregion 属性

protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
is_inventory_holding_unit.DDLBind(ddlDept, "dept", null);
this.ddlDept.Items.Insert(0, new ListItem("-select dept-", "0"));
}
ddlDept.Enabled = IsEnable;
ddlGroup.Enabled = IsEnable;
ddlSection.Enabled = IsEnable;
ddlUnit.Enabled = IsEnable;

ddlDept.Visible = IsDeptVisible;
ddlGroup.Visible = IsGroupVisible;
ddlSection.Visible = IsSectionVisible;
ddlUnit.Visible = IsUnitVisible;

}
protected void ddlDept_SelectedIndexChanged(object sender, EventArgs e)
{
this.ddlGroup.Items.Clear();
this.ddlSection.Items.Clear();
this.ddlUnit.Items.Clear();
is_inventory_holding_unit.DDLBind(ddlGroup, "group", ddlDept.SelectedItem.Value.ToString());
this.ddlGroup.Items.Insert(0, new ListItem("-select group-", "0"));
this.ddlSection.Items.Insert(0, new ListItem("-select section-", "0"));
this.ddlUnit.Items.Insert(0, new ListItem("-select unit-", "0"));
}

protected void ddlGroup_SelectedIndexChanged(object sender, EventArgs e)
{
this.ddlSection.Items.Clear();
this.ddlUnit.Items.Clear();
is_inventory_holding_unit.DDLBind(ddlSection, "section", ddlGroup.SelectedItem.Value.ToString());
this.ddlSection.Items.Insert(0, new ListItem("-select section-", "0"));
this.ddlUnit.Items.Insert(0, new ListItem("-select unit-", "0"));
}

protected void ddlSection_SelectedIndexChanged(object sender, EventArgs e)
{
this.ddlUnit.Items.Clear();
is_inventory_holding_unit.DDLBind(ddlUnit, "unit", ddlSection.SelectedItem.Value.ToString());
this.ddlUnit.Items.Insert(0, new ListItem("-select unit-", "0"));
}

 

#region Load时赋值
public void dept(string id)
{
is_inventory_holding_unit.DDLBind(ddlDept, "dept", null);
ddlDept.SelectedValue = id;
ddlDept_SelectedIndexChanged(null, null);
}
public void group(string id)
{
ddlGroup.SelectedValue = id;
ddlGroup_SelectedIndexChanged(null, null);
}
public void section(string id)
{
ddlSection.SelectedValue = id;
ddlSection_SelectedIndexChanged(null, null);
}
public void unit(string id)
{
if (id == null)
return;
if (id == "")
return;

ddlUnit.SelectedValue = id;
}
#endregion