如何在GridView中限制文本框模板字段的文本长度？

Question

            <asp:GridView ID="CommentGrid" GridLines="None" runat="server" AutoGenerateColumns="False">
            <Columns>
                <asp:BoundField HeaderText="No." DataField="Num" >
                    <HeaderStyle HorizontalAlign="Left" />
                </asp:BoundField>
                <asp:BoundField HeaderText="Subject Name" DataField="SubjectName">
                    <HeaderStyle HorizontalAlign="Left" />
                </asp:BoundField>
                <asp:TemplateField HeaderText="Comment">
                    <ItemTemplate>
                        <asp:TextBox ID="CommentBox" runat="server" TextMode="MultiLine" CssClass="commentTbx" MaxLength="2"></asp:TextBox>
                    </ItemTemplate>
                    <HeaderStyle HorizontalAlign="Left" />
                </asp:TemplateField>
            </Columns>
        </asp:GridView>

The above Maxlength="2" doesnt work!! I even tried other method like databound, and foreach loop to code it but it still fails.

Answer 1

User RegularExpressionValidator. The following accepts minimum characters 0 and maximum 2 characters.

  <asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server" 
        ControlToValidate="CommentBox" ErrorMessage="Out of Range Max 2 Chars" 
        ValidationExpression=".{0,2}"></asp:RegularExpressionValidator>

MaxLength does not work on MultiLine mode.

Answer 2

您是否尝试过<EditItemTeplate>而不是<ItemTemplate>吗？

Answer 3

Yes, it is because of TextMode="MultiLine" . You need some javascript to check total chars and impose limit.