Question

我想清空Panel中的文本框控件。请解释一下。

下面是我的代码：

<asp:Panel ID="Panel_CreateLead" runat="server" Visible="false" BackColor="#eff2f6"  Width="98%">

<asp:Literal ID="LiteralNoLead" runat="server" Text="<span style='color:red'>No Lead Exists. Please fill the Lead Template to Create New Lead.</span>"></asp:Literal> 
<asp:Table ID="Table_CreateLead" runat="server" Width="98%"  CellSpacing="1"  CellPadding="1"  
        Font-Names="Tahoma" BorderColor="#eff2f6" BorderStyle="Dashed">
<asp:TableHeaderRow HorizontalAlign="Center">
    <asp:TableHeaderCell Text="Lead Template" Font-Bold="true" ColumnSpan="4"  Font-Size="Large" />
</asp:TableHeaderRow>
<asp:TableRow ID="TableRow11" runat="server">
       <asp:TableCell Text="General"  Font-Bold="true"  ForeColor="Blue"></asp:TableCell>
</asp:TableRow>
<asp:TableRow ID="TableRow1"  runat="server">
    <asp:TableCell Text="Topic">
        <asp:Literal ID="Literal_Topic"  Text="<span style='color:red'>*</span>" runat="server" />
    </asp:TableCell>
    <asp:TableCell ColumnSpan="3">
        <asp:TextBox ID="TextBox_leadname" Width="80%" runat="server"></asp:TextBox> 
        <asp:RequiredFieldValidator ID="RequiredFieldValidator_TextBox_leadname" runat="server"  ControlToValidate="TextBox_leadname" ValidationGroup="LeadVaidation" ErrorMessage="Enter Topic" />
    </asp:TableCell>
</asp:TableRow> 
<asp:TableRow ID="TableRow23" runat="server">
   <asp:TableCell Text="Currency" ></asp:TableCell>
    <asp:TableCell>
        <asp:DropDownList ID="DropDownList_Currency" runat="server">
        </asp:DropDownList>
    </asp:TableCell>
        <asp:TableCell Text="No. of Employees" ></asp:TableCell>
    <asp:TableCell>
        <asp:TextBox ID="TextBox_Employees" runat="server"></asp:TextBox> 
    </asp:TableCell>
 </asp:TableRow>
 <asp:TableRow>
    <asp:TableCell>
        <asp:Button ID="Button_lead" runat="server" Text="Submit" OnClick="create_lead" ValidationGroup="LeadVaidation"/>
    </asp:TableCell>
     <asp:TableCell>
     <asp:Literal ID="Literal_lead" runat="server"></asp:Literal>
 </asp:TableCell>
</asp:TableRow>
</asp:Table>
</asp:Panel>

我使用了一个方法clearText（Panel_CreateLead）;页面加载不起作用。

cleartext（）中使用的代码：

private void clearText(Panel PanelID)
{
     foreach (Control c in PanelID.Controls)
     {
         if (c is TextBox)
         {
             TextBox questionTextBox = c as TextBox; 
             if (questionTextBox != null)
             {
                 questionTextBox.Text = "";
             }
         }
     }
}

所有这些都不起作用。请帮忙。

Answer 1

这样只会清除直接与你相关的文本框。在你的代码中，如果你做了类似流动的工作

private void clearText(control PanelID)
{
    foreach (Control c in PanelID.Controls)
    {
        if (c is TextBox)
        {
            TextBox questionTextBox = c as TextBox; 
            if (questionTextBox != null)
            {
                questionTextBox.Text = "";
            }
        }

        if(c.Controls.count > 0)
        {
            cleartest(c)
        }
    }
}

Answer 2

您需要一个递归方法来获取所有控件，否则您将只获得面板下的控件。要get all controls with a recursive method，你可以使用它：

public static IEnumerable<TextBox> GetAllControls(this Control parent)
{
    foreach (Control control in parent.Controls)
    {
        yield return control;
        foreach(Control descendant in control.GetAllControls())
        {
            yield return descendant;
        }
    }
}

您可以修改以仅查找文本框，或者您可以将此方法用作Panel.GetAllControls.OfType<TextBox>()并使用面板内的所有文本框。

Answer 3

以递归方式按类型获取所有控件的扩展方法：

public static IEnumerable<Control> GetChildControls(this Control control) where TControl : Control
{
    var children = (control.Controls != null) ? control.Controls.OfType<Control>() : Enumerable.Empty<Control>();
    return children.SelectMany(c => GetChildControls(c)).Concat(children);
}

用法：

IEnumerable<TextBox> textBoxes = panel.Controls.GetChildControls().OfType<TextBox>();
foreach (TextBox tb in textBoxes)
{
    tb.Text = "";
}

Answer 4

如何清空表格中的所有文本框，然后tr，td，...

foreach (Control c in Table3.Controls)
{
    if (c is System.Web.UI.HtmlControls.HtmlTableRow)
    {
        System.Web.UI.HtmlControls.HtmlTableRow tr;
        tr = (System.Web.UI.HtmlControls.HtmlTableRow)c;
        foreach (Control td in tr.Controls)
        {
            if (td is System.Web.UI.HtmlControls.HtmlTableCell)                        
            {
                System.Web.UI.HtmlControls.HtmlTableCell td1;
                td1 = (System.Web.UI.HtmlControls.HtmlTableCell)td;
                    foreach (Control txtBox in td1.Controls)
                    {
                        if(txtBox is TextBox)
                        {
                            TextBox tt = txtBox as TextBox;
                            tt.Text = string.Empty;
                        }
                    }
                }
            }
        }
    }
}

如何清除面板中的TextBox控件

4 个答案: