啟用和禁用按鈕單擊的字段驗證器

Question

我有兩個按鈕控制。 我想點擊btnavail_Click時禁用文本框的字段驗證器。 它的工作。 但是當我單擊按鈕btnsubmit_Click ，字段驗證器未啟用。

 protected void btnsubmit_Click(object sender, EventArgs e)
        {
            RequiredFieldValidator2.Enabled = true;
            RequiredFieldValidator3.Enabled = true;
            RequiredFieldValidator4.Enabled = true;
            con.Open();
            SqlCommand cmd1 = new SqlCommand("Select * from tblstudentinfo where StudentId=@studentid", con);
            cmd1.Parameters.AddWithValue("@studentid",txtstudentid.Text.ToString());
            SqlDataReader rdr=cmd1.ExecuteReader();
            if(rdr.Read())
            {
                int i=Convert.ToInt32(rdr["Password"]);
                int j=Convert.ToInt32(txtpassword.Text);
                if(i == j)
                {
                    SqlCommand cmd2 = new SqlCommand("select * from tblbookinfo where Name=@bookname", con);
                    cmd2.Parameters.AddWithValue("@bookname", txtbookname.Text.ToString());
                    SqlDataReader rdr1 = cmd2.ExecuteReader();
                    if (rdr1.Read())
                    {
                        int s = Convert.ToInt32(rdr1["BookId"]);
                        SqlCommand cmd = new SqlCommand("inserttotbllendinginfo2", con);
                        cmd.CommandType = CommandType.StoredProcedure;

                        cmd.Parameters.Add(new SqlParameter
                        {
                            ParameterName = "@bookid",
                            SqlDbType = SqlDbType.Int,
                            Value = s
                        });
                        cmd.Parameters.Add(new SqlParameter
                        {
                            ParameterName = "@studentid",
                            SqlDbType = SqlDbType.Int,
                            Value = Convert.ToInt32(txtstudentid.Text)
                        });
                        cmd.Parameters.Add(new SqlParameter
                        {
                            ParameterName = "@noofbooks",
                            SqlDbType = SqlDbType.Int,
                            Value = Convert.ToInt32(txtnoofbook.Text)
                        });
                        cmd.Parameters.Add(new SqlParameter
                        {
                            ParameterName = "@dateoflending",
                            SqlDbType = SqlDbType.Date,
                            Value = txtdate.Text
                        });
                        cmd.ExecuteNonQuery();
                    }
                 }
                else
                {
                    lblpassword.Visible=true;
                    lblpassword.Text="Your password is incorrect. Please Check it";
                    lblpassword.ForeColor = System.Drawing.Color.Red;
                }

                con.Close();
              }
        }

        protected void btnavail_Click(object sender, EventArgs e)
        {
            RequiredFieldValidator2.Enabled = false;
            RequiredFieldValidator3.Enabled = false;
            RequiredFieldValidator4.Enabled = false;

            SqlCommand cmd = new SqlCommand("select * from tblbookinfo where Name=@bookname", con);
            cmd.Parameters.AddWithValue("@bookname", txtbookname.Text.ToString());
            con.Open();
            if (String.IsNullOrEmpty(txtbookname.Text))
            {
                lblbookavail.Visible = true;
                lblbookavail.Text = "Please enter a valid book name";
                lblbookavail.ForeColor = System.Drawing.Color.Red;
            }
            else
            {
            SqlDataReader rdr = cmd.ExecuteReader();            
                if (rdr.Read())
                {
                    string s = rdr["Name"].ToString();
                    if (s != null)
                    {
                        int i = Convert.ToInt32(rdr["AvailableBooks"]);
                        lblbookavail.Visible = true;
                        lblbookavail.Text = (i.ToString());
                    }
            }
            }
           con.Close();
            }

我將兩個按鈕的原因驗證屬性設置為false。 我點擊btnsubmit_Click時需要啟用驗證器。 請有人幫助我。

<table align="center">
            <tr><td>Book Name</td><td><asp:TextBox ID="txtbookname" runat="server"></asp:TextBox></td>
                <td><asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ErrorMessage="Requires book name" ControlToValidate="txtbookname" ForeColor="Red" Text="*"></asp:RequiredFieldValidator></td>
                <td><asp:Button ID="btnavail" runat="server" Text="Book Availability"   OnClick="btnavail_Click" /></td><td><asp:Label ID="lblbookavail" runat="server" Visible="false"></asp:Label></td></tr>
            <tr><td>Student Id</td><td><asp:TextBox ID="txtstudentid" runat="server" ValidationGroup="save"></asp:TextBox></td>
                <td><asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ErrorMessage="Requires Studentid" ControlToValidate="txtstudentid" ForeColor="Red" Text="*"></asp:RequiredFieldValidator></td></tr>
            <tr><td>No of Book</td><td><asp:TextBox ID="txtnoofbook" runat="server" ></asp:TextBox></td>
                <td><asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" ErrorMessage="Requires no of book" ControlToValidate="txtnoofbook" ForeColor="Red" Text="*"></asp:RequiredFieldValidator></td></tr>
            <tr><td>Date of lending</td><td><asp:TextBox ID="txtdate" runat="server" ></asp:TextBox></td></tr>
            <tr><td>Password</td><td><asp:TextBox ID="txtpassword" TextMode="Password" runat="server"  ></asp:TextBox></td>
                <td><asp:RequiredFieldValidator ID="RequiredFieldValidator4" runat="server" ErrorMessage="Requires Studentid" ControlToValidate="txtpassword" ForeColor="Red" Text="*"></asp:RequiredFieldValidator></td>
                <td><asp:Label ID="lblpassword" runat="server" Visible="false"></asp:Label></td></tr>
            <tr><td><asp:Button ID="btnsubmit" runat="server" Text="Submit"  OnClick="btnsubmit_Click" /></td></tr>
            </table>

這是我的HTML代碼。 我想在btnavail_click上為studentid禁用Field驗證器，禁用書籍和密碼。 我再次需要為btnsubmit_click啟用它們

Answer 1

為什么不將ValidationGroup添加到您的文本框和按鈕（btnsubmit）這樣的東西

<asp:TextBox ID="TextBox1" runat="server" ValidationGroup="save"></asp:TextBox>
        <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" 
            ErrorMessage="RequiredFieldValidator" ControlToValidate="TextBox1" 
            ValidationGroup="save"></asp:RequiredFieldValidator>
        <asp:TextBox ID="TextBox2" runat="server" ValidationGroup="save"></asp:TextBox>
        <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" 
            ErrorMessage="RequiredFieldValidator" ControlToValidate="TextBox2" 
            ValidationGroup="save"></asp:RequiredFieldValidator>
        <asp:Button ID="btnAvail" runat="server" Text="Button" ValidationGroup="save" 
            onclick="btnAvail_Click" />
        <asp:Button ID="btnsubmit" runat="server" Text="Button" 
            onclick="btnsubmit_Click" />

在這里，我給文本框提供了一個通用的驗證組（我想在其上激活必要的字段驗證）並提交按鈕。 因此，我的所有驗證僅在提交按鈕時觸發。

使用這種方法的好處是您的所有工作都將在客戶端完成，無需擔心啟用和禁用驗證。

更新只需按原樣使用此代碼即可。

<table align="center">
    <tr>
        <td>
            Book Name
        </td>
        <td>
            <asp:TextBox ID="txtbookname" runat="server"></asp:TextBox>
        </td>
        <td>
            <asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" ErrorMessage="Requires book name"
                ControlToValidate="txtbookname" ForeColor="Red" Text="*"  ValidationGroup="avail"></asp:RequiredFieldValidator>
        </td>
        <td>
            <asp:Button ID="Button1" runat="server" Text="Book Availability" OnClick="btnavail_Click"  ValidationGroup="avail"/>
        </td>
        <td>
            <asp:Label ID="lblbookavail" runat="server" Visible="false"></asp:Label>
        </td>
    </tr>
    <tr>
        <td>
            Student Id
        </td>
        <td>
            <asp:TextBox ID="txtstudentid" runat="server" ValidationGroup="save"></asp:TextBox>
        </td>
        <td>
            <asp:RequiredFieldValidator ID="RequiredFieldValidator4" runat="server" ErrorMessage="Requires Studentid"
                ControlToValidate="txtstudentid" ForeColor="Red" Text="*"  ValidationGroup="save"></asp:RequiredFieldValidator>
        </td>
    </tr>
    <tr>
        <td>
            No of Book
        </td>
        <td>
            <asp:TextBox ID="txtnoofbook" runat="server"></asp:TextBox>
        </td>
        <td>
            <asp:RequiredFieldValidator ID="RequiredFieldValidator5" runat="server" ErrorMessage="Requires no of book"
                ControlToValidate="txtnoofbook" ForeColor="Red" Text="*"  ValidationGroup="save"></asp:RequiredFieldValidator>
        </td>
    </tr>
    <tr>
        <td>
            Date of lending
        </td>
        <td>
            <asp:TextBox ID="txtdate" runat="server"></asp:TextBox>
        </td>
    </tr>
    <tr>
        <td>
            Password
        </td>
        <td>
            <asp:TextBox ID="txtpassword" TextMode="Password" runat="server"></asp:TextBox>
        </td>
        <td>
            <asp:RequiredFieldValidator ID="RequiredFieldValidator6" runat="server" ErrorMessage="Requires Studentid"
                ControlToValidate="txtpassword" ForeColor="Red" Text="*"  ValidationGroup="save"></asp:RequiredFieldValidator>
        </td>
        <td>
            <asp:Label ID="lblpassword" runat="server" Visible="false"></asp:Label>
        </td>
    </tr>
    <tr>
        <td>
            <asp:Button ID="Button2" runat="server" Text="Submit" 
                OnClick="btnsubmit_Click"  ValidationGroup="save" style="height: 26px"/>
        </td>
    </tr>
</table>

Answer 2

這是因為，您在服務器端代碼中啟用了RequiredFieldValidator ，即按鈕單擊事件處理程序和RequiredFieldValidator等驗證控件在客戶端工作。 這意味着當您單擊Submit buttton時，由於您的驗證器已被禁用，因此它無效並且表單已發布到服務器，現在即使您現在啟用Validator，也沒有用，因為表單已經發布。

您應該將每個按鈕控件的CausesValidation屬性設置為true或false ，而不是啟用和禁用驗證器控件，如下所示： -

<asp:Button ID="SubmitButton" runat="server" Text="Submit" 
            CausesValidation="true" OnClick="SubmitButton_Click" />

更新：

由於您不希望在btnavail按鈕上btnavail驗證，因此btnavail按鈕設置CausesValidation="false" ，您的標記應如下所示： -

<asp:Button ID="btnavail" runat="server" Text="Book Availability" 
            CausesValidation="false" OnClick="btnavail_Click" />