Question

将AutoPostback设置为true并使用验证器进行下拉。当我从下拉列表中选择“无效”值时，验证器消息简要说明，然后发生回发并且错误消息消失了！这是我的代码：

<asp:TextBox ID="SerialFrom_txt" runat="server" BackColor="White" BorderColor="#188F3E"
                            BorderStyle="Solid" BorderWidth="3px" Width="200px" OnTextChanged="SerialFrom_txt_TextChanged"
                            AutoPostBack="true"></asp:TextBox>
                        <asp:RegularExpressionValidator ID="SerialFrom_rv" runat="server" ValidationExpression="^[a-zA-Z]{2}[0-9]{7}$"
                            Text="error" ControlToValidate="SerialFrom_txt" />

我后面的帖子代码是：

protected void SerialFrom_txt_TextChanged(object sender, EventArgs e)
    {

            if (string.Compare(RoleFrom_lbl.Text, SerialFrom_txt.Text) > 0)
            {
                Error_lbl.Text = "Serial From must be greater than " + RoleFrom_lbl.Text + "!";
                SerialFrom_txt.BackColor = System.Drawing.Color.FromName("red");
                SAVE_btn.Enabled = false;
            }

            else
            {
                Error_lbl.Text = "";
                SerialFrom_txt.BackColor = System.Drawing.Color.FromName("white");
                SAVE_btn.Enabled = true;
            }

    }

所以请告诉我该怎么办？

Answer 1

尝试将CausesValidation =“true”添加到文本框中，如下所示：

<asp:TextBox CausesValidation="true" ID="SerialFrom_txt" runat="server" BackColor="White" BorderColor="#188F3E" BorderStyle="Solid" BorderWidth="3px" Width="200px" OnTextChanged="SerialFrom_txt_TextChanged" AutoPostBack="true"></asp:TextBox>

Answer 2

还需要在服务器端设置控制IsValid状态：

将CustomValidator控件添加到表单中;
将CustomValidator.ControlToValidate设置为“SerialFrom_txt”;
处理CustomValidator.ServerValidate事件而不是SerialFrom_txt_TextChanged事件;
在ServerValidate EventArgs args.IsValid属性中设置控件IsValid状态。

使用自动回发和验证器

2 个答案: