c# - 是否可以在 C# 中的 gridview 上进行验证？

Question

我有一个具有插入功能的 gridview，我试图根据行数限制 INSERT 语句。当前设置方式的问题是，当我输入新行时，验证检查有效，但该行不包含任何数据，因此空行被插入到 gridview 中。

当我在调试器中执行代码时，局部变量都显示为 ""，即使我在按下提交之前输入了数据。

当我在没有任何验证的情况下将代码块移动到 AddNewCustomer 时，它可以正常工作。我试着做这样的事情:

(MGRchk 设置为 = datatable.rows.count)

private void BindData()
{
    string strQuery = "SELECT Person.PersonID, Person.FirstName AS FirstName, Person.LastName AS LastName, Person.Emergency# AS Emergency#, Person.Cell# AS Cell#, Person.Age AS Age, " +
                         "Person.ActivityCard AS ActivityCard, Person.CraftType AS CraftType, Person.Initials AS Initials, Person.Group# AS Group# " +
"FROM Person INNER JOIN " +
                         "TripSchedule ON Person.PersonID = TripSchedule.PersonID INNER JOIN Bus ON TripSchedule.BusID = Bus.BusID where TripSchedule.Date = '" + TextBox1.Text + "' and " +
                         "TripSchedule.Time = '" + ddlTripTime.SelectedItem + "' and TripSchedule.TripType = '" + ddlTripType.SelectedItem + "' and Bus.Bus# = '" + ddlBus.SelectedItem + "' order by Person.Group#";

    SqlCommand cmd = new SqlCommand(strQuery);
    TRIPTYPE = ddlTripType.SelectedItem.ToString();

    GridView1.DataSource = GetData(cmd);
    GridView1.DataBind();    
}

private DataTable GetData(SqlCommand cmd)
{
    DataTable dt = new DataTable();
    SqlConnection conn = new SqlConnection(strConnString);
    SqlDataAdapter adapter = new SqlDataAdapter();
    cmd.CommandType = CommandType.Text;
    cmd.Connection = conn;
    adapter.SelectCommand = cmd;
    adapter.Fill(dt);
    int dtr = 0;
    dtr = dt.Rows.Count;
    MGRchk = dtr;

    if (dt.Rows.Count > 0)
    {
        Formats();
        PrintTable(dt);
        lblAct.Visible = false;
        lblAgee.Visible = false;
        lblBoats.Visible = false;
        lblCells.Visible = false;
        lblEmer.Visible = false;
        lblFirst.Visible = false;
        lblGroups.Visible = false;
        lblInit.Visible = false;
        lblLast.Visible = false;
        txtAct.Visible = false;
        ddlAgeR.Visible = false;
        ddlBoat1.Visible = false;
        txtCells.Visible = false;
        txtEmer.Visible = false;
        txtFirst.Visible = false;
        txtGroups.Visible = false;
        txtInit.Visible = false;
        txtLast.Visible = false;
        btnSubmitted.Visible = false;
    }
    else
    {
        lblAct.Visible = true;
        lblAgee.Visible = true;
        lblBoats.Visible = true;
        lblCells.Visible = true;
        lblEmer.Visible = true;
        lblFirst.Visible = true;
        lblGroups.Visible = true;
        lblInit.Visible = true;
        lblLast.Visible = true;
        txtAct.Visible = true;
        ddlAgeR.Visible = true;
        ddlBoat1.Visible = true;
        txtCells.Visible = true;
        txtEmer.Visible = true;
        txtFirst.Visible = true;
        txtGroups.Visible = true;
        txtInit.Visible = true;
        txtLast.Visible = true;
        btnSubmitted.Visible = true;
        txtAct.Text = "";
        txtCells.Text = "";
        txtEmer.Text = "";
        txtFirst.Text = "";
        txtGroups.Text = "";
        txtInit.Text = "";
        txtLast.Text = "";
    }

protected void AddNewCustomer(object sender, EventArgs e)
{ 
    BindData();

    switch(TRIP)
    {
        case "CANOE":
        if(MGRchk < 24)
        {
            ValidatedAdd(sender, e)
            break;
        }
        else
        {
            lblError1.Text = error1;
        }    
    }
    //etc

protected void ValidatedAdd(object sender, EventArgs e)
{
    string nFirstName = ((TextBox)GridView1.FooterRow.FindControl("txtFirstName")).Text;
    string nLastName = ((TextBox)GridView1.FooterRow.FindControl("txtLastName")).Text;
    string nEmergency = ((TextBox)GridView1.FooterRow.FindControl("txtEmergency")).Text;
    string nCell = ((TextBox)GridView1.FooterRow.FindControl("txtCell")).Text;
    string nAge = ((TextBox)GridView1.FooterRow.FindControl("txtAge")).Text;
    string nActivityCard = ((TextBox)GridView1.FooterRow.FindControl("txtActivityCard")).Text;
    string nInitials = ((TextBox)GridView1.FooterRow.FindControl("txtInitials")).Text;
    string nGroup = ((TextBox)GridView1.FooterRow.FindControl("txtGroup")).Text;
    string aboat = ((DropDownList)GridView1.FooterRow.FindControl("ddlBoat")).Text;

    SqlConnection con = new SqlConnection(strConnString);
    SqlCommand cmd = new SqlCommand("INSERT INTO Person(FirstName, LastName, Emergency#, Cell#, Age, ActivityCard, CraftType, Initials, Group#) " +
      "values(@FirstName, @LastName, @Emergency, @Cell, @Age, @ActivityCard, @Boat, @Initials, @Group);"
      + "insert into TripSchedule(TripType, PersonID, Time, Date, BusID) values (@Type, SCOPE_IDENTITY(), @Time, @Date, @Bus);" +
      "SELECT Person.PersonID, Person.FirstName AS FirstName, Person.LastName AS LastName, Person.Emergency# AS Emergency#, Person.Cell# AS Cell#, Person.Age AS Age, " +
      "Person.ActivityCard AS ActivityCard, Person.CraftType AS CraftType, Person.Initials AS Initials, Person.Group# AS Group# " +
      "FROM Person INNER JOIN " +
      "TripSchedule ON Person.PersonID = TripSchedule.PersonID INNER JOIN Bus on Bus.BusID = TripSchedule.BusID where TripSchedule.Date = @Date and " +
      "TripSchedule.Time = @Time and TripSchedule.TripType = @Type and Bus.BusID = @Bus order by Person.Group#;");



    cmd.Parameters.Add("@FirstName", SqlDbType.VarChar).Value = nFirstName;
    cmd.Parameters.Add("@LastName", SqlDbType.VarChar).Value = nLastName;
    cmd.Parameters.Add("@Emergency", SqlDbType.NChar).Value = nEmergency;
    cmd.Parameters.Add("@Cell", SqlDbType.NChar).Value = nCell;
    cmd.Parameters.Add("@Age", SqlDbType.NChar).Value = nAge;
    cmd.Parameters.Add("@ActivityCard", SqlDbType.NChar).Value = nActivityCard;
    cmd.Parameters.Add("@Initials", SqlDbType.NChar).Value = nInitials;
    cmd.Parameters.Add("@Group", SqlDbType.VarChar).Value = nGroup;
    cmd.Parameters.AddWithValue("@Date", TextBox1.Text);
    cmd.Parameters.AddWithValue("@Time", ddlTripTime.SelectedItem.ToString());
    cmd.Parameters.AddWithValue("@Type", ddlTripType.SelectedItem.ToString());
    cmd.Parameters.AddWithValue("@Boat", aboat.ToString());
    cmd.Parameters.AddWithValue("@Bus", ddlBus.SelectedItem.ToString());

    GridView1.DataSource = GetData(cmd);
    GridView1.DataBind();
}

Answer 1

每次添加新客户时，您都在执行插入操作之前绑定(bind) GridView。。这种重新绑定(bind)每次都会清除您的值。

要么删除 AddNewCustomer 中的绑定(bind)(因为无论如何您都会在 ValidateAdd 中再次绑定(bind))，或者删除 ValidateAdd 中的绑定(bind)并将绑定(bind)移动到AddNewCustomer 在插入之后。