选中的下拉列表项目名称在其他下拉列表中不可见 [英] selected dropdownlist item name cannot visible in the other dropdown

问题描述

假设我有三个DropDownLists，每个都包含以下项目：A，B，C，D和E.these正在从表数据中恢复。如果我从DropDownList 2中选择了项目D，则DropDownList1和3将仅显示项目A，B，C和E，因为我的代码用于从其他DropDownLists中删除/禁用所选项目。我想添加选择选项对于所有下拉列表，如果我点击它不会去'选择'选项。任何的想法？请帮忙。



谢谢

解决方案

检查下面的代码和平。它可能对你有帮助。



假设我们有3个dorpdown。

 <   asp：DropDownList     ID   =  DropDownList1    runat   =  server < span class =code-attribute>  宽度  =  150px  
   
                           AutoPostBack   =   True    onselectedindexchanged  < span class =code-keyword> =  DropDownList1_SelectedIndexChanged >  
 <   asp：ListItem  >  a <   / asp：ListItem  >  
 <   asp：ListItem  >  b <   / asp：ListItem  >  
 <   asp：ListItem  >  c <   / asp：ListItem  >  
 <   asp：ListItem  >  1 <   / asp：ListItem  >  
 <   asp：ListItem  >  2 <   / asp：ListItem  >  
 <   asp：ListItem  >  3 <   / asp：ListItem  >  
 <   asp：ListItem  >  <  < span class =code-leadattribute> / asp：ListItem  >  
 <   / asp：DropDownList  >  
 <   br     /  >  
 <   asp：DropDownList     ID   =  DropDownList2    runat   =  server   宽度  =  150px  
   
                           AutoPostBack   =  True    onselectedindexchanged   =  DropDownList2_SelectedIndexChanged >  
 <   asp：ListItem  >  a <   / asp：ListItem  >  
 <   asp：ListItem  >  b <   / asp：ListItem  >  
 <   asp：ListItem  < span class =code-keyword>>  c <   / asp：ListItem  >  
 <   asp：ListItem  >  1 <   / asp：ListItem  >  
 <   asp：ListItem   >  2 <   / asp：ListItem  >  
 <   asp：ListItem  >  3 <   / asp：ListItem  >  
  <   asp：ListItem  >  < ;   / asp：ListItem  >  
 <   / asp：DropDownList  >  
 <   br     /  >  
 <   asp：DropDownList     ID   =   DropDownList3    runat   =  server   宽度  =  150px  
   
  < span class =code-attribute>                         AutoPostBack   =  True    onselectedindexchanged   =  DropDownList3_SelectedIndexChanged  >  
 <   asp：ListItem  >  a <   / asp：ListItem  >  
 <   asp：ListItem  >  b <   / asp：ListItem  >  
 <  < span class =code-leadattribute> asp：ListItem  >  c <  < span class =code-leadattribute> / asp：ListItem  >  
 <   asp：ListItem  >  1 <   / asp：ListItem  >  
 <   asp：ListItem  >  2 <   / asp：ListItem  >  
 <   asp：ListItem  >  3 <   / asp：ListItem  >  
 <   asp： ListItem  >  <   / asp： ListItem  >  
 <   / asp：DropDownList  >  

以下是代码背后的代码。

  protected   void  DropDownList1_SelectedIndexChanged（ object  sender，EventArgs e）
 {
  string  item = DropDownList1.Text; 
 DropDownList2.Items.Remove（item）; 
 DropDownList3.Items.Remove（item）; 
} 
 
  protected   void  DropDownList2_SelectedIndexChanged（ object  sender，EventArgs e）
 {
  string  item = DropDownList2.Text; 
 DropDownList1.Items.Remove（item）; 
 DropDownList3.Items.Remove（item）; 
} 
 
  protected   void  DropDownList3_SelectedIndexChanged（ object  sender，EventArgs e）
 {
  string  item = DropDownList3.Text; 
  //  在这里，您可以绑定Dropdown，然后删除该项目。在您需要的任何地方执行此操作 
 DropDownList1.Items.Remove（item）; 
 DropDownList2.Items.Remove（item）; 
} 

如果你想在页面加载上做类似的事情，你也可以根据上面的代码来做。

Suppose I have three DropDownLists each with the items: A, B,C,D and E.these are retriving from table data. If I selected item D from the DropDownList 2, then DropDownList1 and 3 will show the items A, B, C and E only, since my code works to remove / disable the selected item from the other DropDownLists.and i want to add Select option for all dropdownlist, if i click on that it wont go 'select' option. Any idea? Please help.

Thank You

解决方案

Check below peace of code. It might help you.

Let's say we have 3 dorpdown.

<asp:DropDownList ID="DropDownList1" runat="server" Width="150px"

            AutoPostBack="True" onselectedindexchanged="DropDownList1_SelectedIndexChanged">
            <asp:ListItem>a</asp:ListItem>
            <asp:ListItem>b</asp:ListItem>
            <asp:ListItem>c</asp:ListItem>
            <asp:ListItem>1</asp:ListItem>
            <asp:ListItem>2</asp:ListItem>
            <asp:ListItem>3</asp:ListItem>
            <asp:ListItem></asp:ListItem>
        </asp:DropDownList>
        <br />
        <asp:DropDownList ID="DropDownList2" runat="server" Width="150px"

            AutoPostBack="True" onselectedindexchanged="DropDownList2_SelectedIndexChanged">
            <asp:ListItem>a</asp:ListItem>
            <asp:ListItem>b</asp:ListItem>
            <asp:ListItem>c</asp:ListItem>
            <asp:ListItem>1</asp:ListItem>
            <asp:ListItem>2</asp:ListItem>
            <asp:ListItem>3</asp:ListItem>
            <asp:ListItem></asp:ListItem>
        </asp:DropDownList>
        <br />
        <asp:DropDownList ID="DropDownList3" runat="server" Width="150px"

            AutoPostBack="True" onselectedindexchanged="DropDownList3_SelectedIndexChanged">
            <asp:ListItem>a</asp:ListItem>
            <asp:ListItem>b</asp:ListItem>
            <asp:ListItem>c</asp:ListItem>
            <asp:ListItem>1</asp:ListItem>
            <asp:ListItem>2</asp:ListItem>
            <asp:ListItem>3</asp:ListItem>
            <asp:ListItem></asp:ListItem>
        </asp:DropDownList>

Below is the code behind code.

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
        {
            string item = DropDownList1.Text;
            DropDownList2.Items.Remove(item);
            DropDownList3.Items.Remove(item);
        }

        protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e)
        {
            string item = DropDownList2.Text;
            DropDownList1.Items.Remove(item);
            DropDownList3.Items.Remove(item);
        }

        protected void DropDownList3_SelectedIndexChanged(object sender, EventArgs e)
        {
            string item = DropDownList3.Text;
            //here you can bind the Dropdown and then remove the item. Do this wherever you require to do
            DropDownList1.Items.Remove(item);
            DropDownList2.Items.Remove(item);
        }

If you want to do something similar on Page Load you can do that also based on above code.

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