Question

我在这里遇到的问题是，代码实际上有效，但它只能运行一次。例如，如果我已经选择了数据库中已有的日期和时间，那么它显示的日期不可用，如果我选择的日期不在数据库中，则显示可用的日期。在此之前没问题，但是在这两个标签都显示一次之后如果我第三次选择不可用的日期，代码就不再执行了。我的意思是，它只停留在之前显示的标签上。我该怎么做这个循环？

前端代码如下：

<form id="form1" runat="server">
    <asp:ScriptManager ID="scriptmanager1" runat="server">
    </asp:ScriptManager>
    <script type="text/javascript" language="javascript">
        Sys.Application.add_load(jScript);
    </script>
    <div id="dvRecWed" style="display: none">
        <asp:UpdatePanel ID="PnlUsrDetails" runat="server">
            <ContentTemplate>
                <asp:TextBox ID="txtReceptionDate" class="form-control" autocomplete="off" CssClass="datepicker" placeholder="mm/dd/yy" AutoPostBack="true" OnTextChanged="reset_ddl" runat="server"></asp:TextBox>
                <asp:DropDownList AutoPostBack="true" ID="ddlReceptionTime" runat="server" OnSelectedIndexChanged="txtUsername_TextChanged">
                    <asp:ListItem Value="-1">--Select--</asp:ListItem>
                    <asp:ListItem Value="Forenoon">Forenoon</asp:ListItem>
                    <asp:ListItem Value="Afternoon">Afternoon</asp:ListItem>
                    <asp:ListItem Value="FullDay">Full Day</asp:ListItem>
                </asp:DropDownList>
                <div id="checkdate" class="checkdate" runat="server" visible="false">
                    <asp:Image ID="imgstatus" runat="server" Width="17px" Height="17px" />
                    <asp:Label ID="lblStatus" runat="server"></asp:Label>
                </div>
            </ContentTemplate>
        </asp:UpdatePanel>
    </div>
</form>

后端代码如下

protected void txtUsername_TextChanged(object sender, EventArgs e)
{
    if (!string.IsNullOrEmpty(ddlReceptionTime.Text))
    {
        string connString = ConfigurationManager.ConnectionStrings["MandapamDatabase"].ConnectionString;
        OleDbConnection connection = new OleDbConnection(connString);
        // SqlCommand cmd = new SqlCommand("select * from UserInformation where UserName=@Name", con);
        string selectQuery = "SELECT FunctionTime FROM function WHERE FunctionDate=@FunctionDate AND FunctionTime='FullDay'";
        connection.Open();
        OleDbCommand command = new OleDbCommand(selectQuery, connection);
        command.Connection = connection;
        command.CommandText = selectQuery;
        command.CommandType = CommandType.Text;
        command.Parameters.AddWithValue("@FunctionDate", txtReceptionDate.Text);
        command.Parameters.AddWithValue("@FunctionTime", ddlReceptionTime.Text);
        OleDbDataReader dr = command.ExecuteReader();
        if (dr.HasRows)
        {
            checkdate.Visible = true;
            imgstatus.ImageUrl = "~/img/cross.png";
            lblStatus.Text = "Date Unavailable";
            lblStatus.ForeColor = System.Drawing.Color.Red;
        }
        else
        {
            checkdate.Visible = true;
            imgstatus.ImageUrl = "~/img/check.png";
            lblStatus.Text = "Date available";
        }
    }

    else if (!string.IsNullOrEmpty(ddlReceptionTime.Text))
    {
        string connString = ConfigurationManager.ConnectionStrings["MandapamDatabase"].ConnectionString;
        OleDbConnection connection = new OleDbConnection(connString);
        // SqlCommand cmd = new SqlCommand("select * from UserInformation where UserName=@Name", con);
        string selectQuery = "SELECT FunctionTime FROM function WHERE FunctionDate=@FunctionDate AND FunctionTime=@FunctionTime";
        connection.Open();
        OleDbCommand command = new OleDbCommand(selectQuery, connection);
        command.Connection = connection;
        command.CommandText = selectQuery;
        command.CommandType = CommandType.Text;
        command.Parameters.AddWithValue("@FunctionDate", txtReceptionDate.Text);
        command.Parameters.AddWithValue("@FunctionTime", ddlReceptionTime.Text);
        OleDbDataReader dr = command.ExecuteReader();
        if (dr.HasRows)
        {
            checkdate.Visible = true;
            imgstatus.ImageUrl = "~/img/cross.png";
            lblStatus.Text = "Date Unavailable";
            lblStatus.ForeColor= System.Drawing.Color.Red;

        }
        else
        {
            checkdate.Visible = true;
            imgstatus.ImageUrl = "~/img/check.png";
            lblStatus.Text = "Date Available";
        }
    }
    else
    {
        checkdate.Visible = false;
    }
}



protected void reset_ddl(object sender, EventArgs e)
{
    ddlReceptionTime.SelectedValue = "-1";
}

Answer 1

您的预期行为是什么？

<asp:TextBox ID="txtReceptionDate" class="form-control" autocomplete="off" CssClass="datepicker" placeholder="mm/dd/yy" AutoPostBack="true" OnTextChanged="reset_ddl" runat="server"></asp:TextBox>
<asp:DropDownList AutoPostBack="true" ID="ddlReceptionTime" runat="server" OnSelectedIndexChanged="txtUsername_TextChanged">
    <asp:ListItem Value="-1">--Select--</asp:ListItem>
    <asp:ListItem Value="Forenoon">Forenoon</asp:ListItem>
    <asp:ListItem Value="Afternoon">Afternoon</asp:ListItem>
    <asp:ListItem Value="FullDay">Full Day</asp:ListItem>
</asp:DropDownList>

根据您的代码，您在下拉列表的txtUsername_TextChanged事件期间调用OnSelectedIndexChanged。

这意味着即使您更改日期选择器的日期值，该事件也不会触发。相反，reset_ddl将在OnTextChanged事件期间触发。

我们不知道reset_dll做了什么。如果您希望检查日期可用性的代码触发，则将其放在日期选择器文本框的OnTextChanged事件上，而不是放在下拉列表中。

Answer 2

我发现问题所在的地方实际上代码没有问题，它的工作完全问题在我的数据库中

日期可用性检查器仅工作一次

2 个答案: