Question

我是一个新的C＃程序员，我已经开始使用C＃一个月了，到目前为止，我可以说很好，但是我正在处理一个简单的情况，但我仍然没有让它工作，那里是场景：

我有2个表格父和一个孩子，父母包含一个Xtragrid控件和一个打开第二个表单的按钮，并在第二个表单中加载带有值的textBoxes，第二个有一个按钮来更新值以防万一任何变化。但我仍然没有让它工作，我有以下错误：

必须在@ID
处声明SCALAR VARIABLE

我理解问题的原因，但我不能解决它，我已经做了一些研究来解决自己，但我仍然没有设法让它工作最后一行

da.updatecommand.parameters.addwithvalues("ID@",ds.tables["tblLesseeYW"].Rows[LesseeYW.Position][0];

我已经完成但是它没有工作（LesseeYW是我的绑定源对象，但它不会在当前上下文中退出，也不会退出可理解的数据集：有代码需要帮助pleaese

// This the class ive created to retrieve all Columns from the SQl server data base
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace YoungWoman
 {
   public static class GetRowData
{

   public static int LesseeId;
   public static byte LesseePic;
   public static string LesseeName;
   public static string LesseeLastName;
   public static string PassportNo;
   public static string IDNo;
   public static DateTime BirthDate;
   public static string Gender;
   public static string Country;
   public static string City;
   public static string Province;
   public static string LesseePostalCode;
   public static string MobileNo;
   public static string HomePhoneNo;
   public static string TutorName;
   public static string TutorLastName;
   public static string AddressTutor;
   public static string AddressLessee;
   public static string TutorPhoneNo;
   public static string TutorEmail;




     }
   }


  // the parent form 


     namespace YoungWoman
   {

     public partial class Lessee2 : UserControl
    {
      DataSet ds = new DataSet();
       DataView dv ;
      SqlDataAdapter daLessee = new SqlDataAdapter();
      SqlDataAdapter daReservation = new SqlDataAdapter();
      BindingSource LesseeYW = new BindingSource();

       BindingSource ReservationCenterYW = new BindingSource();

       SqlConnection conne = SqlCoonectionSEtup.GetConnection;

// the button that opens the Child Form

    private void EditLesseeFrm_Click(object sender, EventArgs e)
    {
        Lesseefrm Lessee = new Lesseefrm(Utils.Formtype.edit, 1);
        Lessee.LesseeEventHandler += new EventHandler(RefreshLesseeGrid);

        GetRowData.LesseeId = Convert.ToInt32(gridView1.GetRowCellValue    (gridView1.FocusedRowHandle, "LesseeId"));
        GetRowData.LesseeName = Convert.ToString(gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "LesseeName"));
        GetRowData.LesseeLastName = Convert.ToString(gridView1.GetRowCellValue(gridView1.FocusedRowHandle,"LesseeLastName"));
        GetRowData.PassportNo = Convert.ToString(gridView1.GetRowCellValue(gridView1.FocusedRowHandle,"PassportNo"));
        GetRowData.Gender = Convert.ToString(gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "Gender"));
        GetRowData.Province = Convert.ToString(gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "Province"));
        GetRowData.BirthDate = Convert.ToDateTime(gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "BirthDate"));
        GetRowData.City = Convert.ToString(gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "City"));
        GetRowData.Country = Convert.ToString(gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "Country"));
        GetRowData.MobileNo = Convert.ToString(gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "MobileNo"));
        GetRowData.HomePhoneNo = Convert.ToString(gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "HomePhoneNo"));
        GetRowData.IDNo = Convert.ToString(gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "IDNo"));
        GetRowData.AddressLessee = Convert.ToString(gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "AddressLessee"));
        GetRowData.AddressTutor = Convert.ToString(gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "AddressTutor"));
        GetRowData.LesseePostalCode = Convert.ToString(gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "LesseePostalCode"));
        GetRowData.TutorName = Convert.ToString(gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "TutorName"));
        GetRowData.TutorLastName = Convert.ToString(gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "TutorLastName"));
        GetRowData.TutorPhoneNo = Convert.ToString(gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "TutorPhoneNo"));
        GetRowData.TutorEmail = Convert.ToString(gridView1.GetRowCellValue(gridView1.FocusedRowHandle, "TutorEmail"));


        Lessee.ShowDialog();
    }



     ( // Child LOad_form if form type == Edit )


          if (formtype == Formtype.edit && Lesseeid > 0)
            {



                LesseeIdtextEdit.Enabled = false;
                ClearBtnlayoutControlItem26.Visibility =    DevExpress.XtraLayout.Utils.LayoutVisibility.Never;
                SaveBtn.Text = "&Edit";
                SaveBtn.Image = Resources.brush_16;
                this.Text = string.Format(" Edit Lessee Information - YW Residence ");

                LesseeIdtextEdit.Text = Convert.ToInt32(GetRowData.LesseeId).ToString();
                txtName.Text = GetRowData.LesseeName;
                txtLAstname.Text = GetRowData.LesseeLastName;
                txtPassport.Text = GetRowData.PassportNo;
                txtID.Text = GetRowData.IDNo;
                GendercomboBoxEdit.SelectedItem = GetRowData.Gender;
                DobdateEdit.DateTime = GetRowData.BirthDate;
                CountrycomboBoxEdit.SelectedItem = GetRowData.Country;
                txtProvince.Text = GetRowData.Province;
                txtCity.Text = GetRowData.City;
                txtPostalCode.Text = GetRowData.LesseePostalCode;
                LesseememoEdit1.Text = GetRowData.AddressLessee;
                txtMobile.Text = GetRowData.MobileNo;
                txtHomePhone.Text = GetRowData.HomePhoneNo;
                txtTutorName.Text = GetRowData.TutorName;
                txttutorLastname.Text = GetRowData.TutorLastName;
                tutorAddresstxt.Text = GetRowData.AddressTutor;
                txtTutorMobile.Text = GetRowData.TutorPhoneNo;
                txtEmail.Text = GetRowData.TutorEmail;



            }



     public event System.EventHandler LesseeEventHandler;

     private void SaveBtn_Click(object sender, EventArgs e)

       if (formtype == Formtype.edit && Lesseeid > 0)
            {

                MemoryStream ms = new MemoryStream();
                PicBox1.Image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
                byte[] Pic_arr = new byte[ms.Length];
                ms.Position = 0;
                ms.Read(Pic_arr, 0, Pic_arr.Length);

                try
                {

                    da.UpdateCommand = new SqlCommand(" UPDATE LesseeYW SET LesseePic = @image , LesseeName = @Name, LesseeLastName = @Last , PassportNo = @pass,IDNo = @Number, BirthDate =@birth ,Gender = @gender , Country =@country,LesseePostalCode = @Postal,City = @city , Province = @province,MobileNo = @Mobile,HomePhoneNo = @phone,TutorName = @tutor,TutorLastName=@Tlast,AddressTutor = @line1,AddressLessee=@line2,TutorPhoneNo = @Tphone,TutorEmail =@Temail WHERE LesseeId = @ID ", conne);
                    da.UpdateCommand.Parameters.AddWithValue("@image", Pic_arr);
                    da.UpdateCommand.Parameters.AddWithValue("@Name", txtName.Text);
                    da.UpdateCommand.Parameters.AddWithValue("@Last", txtLAstname.Text);
                    da.UpdateCommand.Parameters.AddWithValue("@pass", txtPassport.Text);
                    da.UpdateCommand.Parameters.AddWithValue("@Number", txtID.Text);
                    da.UpdateCommand.Parameters.AddWithValue("@birth", DobdateEdit.DateTime);
                    da.UpdateCommand.Parameters.AddWithValue("@gender", GendercomboBoxEdit.SelectedItem.ToString());
                    da.UpdateCommand.Parameters.AddWithValue("@country", CountrycomboBoxEdit.SelectedItem.ToString());
                    da.UpdateCommand.Parameters.AddWithValue("@Postal", txtPostalCode.Text);
                    da.UpdateCommand.Parameters.AddWithValue("@city", txtCity.Text);
                    da.UpdateCommand.Parameters.AddWithValue("@province", txtProvince.Text);
                    da.UpdateCommand.Parameters.AddWithValue("@Mobile", txtMobile.Text);
                    da.UpdateCommand.Parameters.AddWithValue("@phone", txtHomePhone.Text);
                    da.UpdateCommand.Parameters.AddWithValue("@tutor", txtTutorName.Text);
                    da.UpdateCommand.Parameters.AddWithValue("@Tlast", txttutorLastname.Text);
                    da.UpdateCommand.Parameters.AddWithValue("@line1", tutorAddresstxt.Text);
                    da.UpdateCommand.Parameters.AddWithValue("@line2", LesseememoEdit1.Text);
                    da.UpdateCommand.Parameters.AddWithValue("@Tphone", txtTutorMobile.Text);
                    da.UpdateCommand.Parameters.AddWithValue("@Temail", txtEmail.Text);
                   //da.UpdateCommand.Parameters.AddWithValue("@ID"




                    da.UpdateCommand.ExecuteNonQuery();
                    conne.Close();
                    MessageBox.Show("Lessee Details Updated ", "Confirmation", MessageBoxButtons.OK, MessageBoxIcon.Information);
                    this.Close();

                }

                catch (Exception Ex)
                {

                    MessageBox.Show(Ex.Message);

                }

            }

Answer 1

起初你应该更加客观。不要将类的所有变量声明为公共静态。你应该把它们变成私人的。要获得访问权限，您必须声明属性。

像这样：

private string name;

public string Name
{
  get {return name;}
  set {name = value;}
}

如果您有一个ID，您可以轻松地将其设为只读，而“外部”的任何人都可以修改它，但每个人都可以阅读。

private int leeseId;

public int LeeseID
{
  get{return leeseId;}
}

所以你使用“getter / setter”来提供你的类属性。此外，并非所有变量都应命名为leese ...只需将其命名为id，name，city，pic等。在表单中，您可以从类中创建一个Object。你可以把这个对象命名为Leese。

private Leese leese = new Leese();
leese.id = ???
leese.name = ???

更具可读性。

da.updatecommand.parameters.addwithvalues("ID@",ds.tables["tblLesseeYW"].Rows[LesseeYW.Position][0];

你写了“ID @”但它应该是“@ID”。如果你按照我在顶部的描述建立你的类，你可以使用属性：

da.updatecommand.parameters.addwithvalues("@ID", leese.Id);

我希望能帮到你。

如何从子表单C＃更新父表单上的datagridview

1 个答案: