以下更新数据库的方法称为UpdateHold（）。该对象的实例使用第二个构造函数。我运行调试以验证保持对象“thisHold”是否正在更新表单中正在更改的值。但是当我在提交发生后查看db对象的值时，我看到它在物理数据库中保持不变。为什么不更新？
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Data.Linq;
using System.Text;
using System.Windows.Forms;
namespace Coke_Hold_Database
{
public partial class frmFGHold : Form
{
private PINAuthentication cert = new PINAuthentication();
linqCokeDBDataContext db = new linqCokeDBDataContext();
Record_HoldData thisHold;
bool isNew; //flag if hold is new or not
public frmFGHold()
{
//constructor for new hold
InitializeComponent();
populateLists();
thisHold = new Record_HoldData();
isNew = true;
btnEdit.Visible = false;
}
public frmFGHold(Record_HoldData holdData)
{
//constructor for existing hold (edit)
InitializeComponent();
populateLists();
this.thisHold = holdData;
//fill out the form
FillForm();
isNew = false;
btnEdit.Visible = true;
}
private void FillForm()
{
//fill out the form with existing information
txtPONumber.Text = thisHold.PO_.ToString();
cboProductionSupervisor.SelectedValue = thisHold.ProductionSupervisor;
cboLineNumber.SelectedValue = thisHold.LineNumber;
cboQASupervisor.SelectedValue = thisHold.QASupervisor;
cboFlavorName.SelectedValue = thisHold.Flavor;
cboContainer.Text = thisHold.ContainerType;
cboContainerSize.Text = thisHold.ProductSize;
cboPackage.Text = thisHold.Package;
txtQuantity.Text = thisHold.HoldQty.ToString();
mtbDateCode.Text = thisHold.DateCode;
cboDefectiveComponent.Text = thisHold.NonConformingItem;
cboDefectReason.Text = thisHold.NonConformance;
cboOccuredAt.Text = thisHold.FoundDuring;
chkTestRequired.Checked = (bool) thisHold.TestRequired;
txaDescription.Text = thisHold.Comments;
txaRootCauseAnalysis.Text = thisHold.RootCause;
}
private void UpdateHoldObject()
{
thisHold.PO_ = int.Parse(txtPONumber.Text);
thisHold.ProductionSupervisor = (int)cboProductionSupervisor.SelectedValue;
thisHold.LineNumber = (int) cboLineNumber.SelectedValue;
thisHold.QASupervisor = (int) cboQASupervisor.SelectedValue;
thisHold.Flavor = (int) cboFlavorName.SelectedValue;
thisHold.ContainerType = cboContainer.Text;
thisHold.ProductSize = cboContainerSize.Text;
thisHold.Package = cboPackage.Text;
thisHold.HoldQty = int.Parse(txtQuantity.Text);
thisHold.DateCode = mtbDateCode.Text;
thisHold.NonConformingItem = cboDefectiveComponent.Text;
thisHold.NonConformance = cboDefectReason.Text;
thisHold.FoundDuring = cboOccuredAt.Text;
thisHold.TestRequired = chkTestRequired.Checked;
thisHold.Comments = txaDescription.Text;
thisHold.RootCause = txaRootCauseAnalysis.Text;
}
private void CreateNewHold()
{
db.Record_HoldDatas.InsertOnSubmit(thisHold);
//GenerateHoldNumber()
db.SubmitChanges();
MessageBox.Show(this, "Hold submitted!\n\nYou're hold number is " + thisHold.HoldID.ToString(),"Hold #" + thisHold.HoldID.ToString() + " created", MessageBoxButtons.OK, MessageBoxIcon.Information);
this.Close();
}
private void UpdateHold()
{
db.SubmitChanges();
MessageBox.Show(this, "Hold #" + thisHold.HoldID.ToString() + " updated.", thisHold.HoldID.ToString() + " updated", MessageBoxButtons.OK, MessageBoxIcon.Information);
this.Close();
}
private bool ValidateEntry()
{
//TODO write some frakkin validation
return true;
}
private void GetPIN()
{
frmPINPrompt pin = new frmPINPrompt(cert);
pin.ShowDialog();
}
private void SubmitData()
{
UpdateHoldObject();
GetPIN();
if (ValidateEntry() && cert.authenticated)
{
try
{
if (isNew)
{
thisHold.LabTech = cert.empNumber;
thisHold.LastEditBy = cert.empNumber;
thisHold.HoldStatus = "Open";
thisHold.DateOpened = DateTime.Now;
thisHold.LastEditDate = DateTime.Now;
CreateNewHold();
}
else
{
thisHold.LastEditBy = cert.empNumber;
thisHold.LastEditDate = DateTime.Now;
UpdateHold();
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}
public void populateLists()
{
//load production names
var productionNames =
from a in db.LUT_Employees
where a.position == "Supervisor" && a.department == "Production"
select new { ID = a.ID, Names = a.lastName + ", " + a.firstName };
cboProductionSupervisor.DataSource = productionNames;
cboProductionSupervisor.DisplayMember = "Names";
cboProductionSupervisor.ValueMember = "ID";
//load QA names
var qaNames =
from a in db.LUT_Employees
where a.position == "Supervisor" && a.department == "Quality Assurance"
select new { ID = a.ID, Names = a.lastName + ", " + a.firstName };
cboQASupervisor.DataSource = qaNames;
cboQASupervisor.DisplayMember = "Names";
cboQASupervisor.ValueMember = "ID";
//load flavor names
var flavorNames =
from a in db.LUT_Flavors
select new { ID = a.ID, Flavor = a.flavor };
cboFlavorName.DataSource = flavorNames;
cboFlavorName.DisplayMember = "flavor";
cboFlavorName.ValueMember = "ID";
//load line numbers
var lineNumbers =
(from a in db.LUT_ProductionLines
select new { a.lineNumber }).ToList();
cboLineNumber.DataSource = lineNumbers;
cboLineNumber.DisplayMember = "LineNumber";
cboLineNumber.ValueMember = "LineNumber";
}
private void mtbDateCode_MouseUp(object sender, MouseEventArgs e)
{
SendKeys.Send("{HOME}");
}
private void btnCancel_Click(object sender, EventArgs e)
{
DialogResult result = MessageBox.Show("Are you sure you want to cancel? All data will be lost!", "Confirm Cancel", MessageBoxButtons.YesNo, MessageBoxIcon.Asterisk);
if (result == DialogResult.Yes)
{
this.Close();
}
else { }
}
private void btnSubmit_Click(object sender, EventArgs e)
{
SubmitData();
}
private void linkAutoFill_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
{
//autogenerage date code
mtbDateCode.Text = Etc.BuildDateCode(DateTime.Now,(int)cboFlavorName.SelectedValue,cboContainer.Text,Etc.getDayCode(DateTime.Now),int.Parse(cboLineNumber.Text));
}
private void cboContainerSize_SelectedIndexChanged(object sender, EventArgs e)
{
//load package sizes
var packageSizes =
from a in db.LUT_Packagings
where a.Container == cboContainer.Text && a.Size == cboContainerSize.SelectedValue
select new { ID = a.ID, Size = a.Package };
cboPackage.DataSource = packageSizes;
cboPackage.DisplayMember = "Size";
cboPackage.ValueMember = "ID";
}
private void cboContainer_SelectedIndexChanged(object sender, EventArgs e)
{
//make container size list
var containerSizes =
from a in db.LUT_Containers
where a.ContainerType == cboContainer.Text
select new { ID = a.ID, Size = a.size };
cboContainerSize.DataSource = containerSizes;
cboContainerSize.DisplayMember = "Size";
cboContainerSize.ValueMember = "ID";
//load components
var defectiveComponents =
from a in db.LUT_ContainerComponents
where a.Container == cboContainer.Text
select new { ID = a.ID, Comp = a.Component };
cboDefectiveComponent.DataSource = defectiveComponents;
cboDefectiveComponent.DisplayMember = "Comp";
cboDefectiveComponent.ValueMember = "ID";
}
private void btnEdit_Click(object sender, EventArgs e)
{
//TODO ask verify PIN
foreach (Control c in this.Controls)
{
c.Enabled = true;
}
btnSubmit.Text = "Update Hold";
}
}
}
答案 0 :(得分：4)
数据库未更新，因为您正在db DataContext上提交更改，并且您通过构造函数提供的“hold”未附加到该DataContext。因此，db DataContext无法跟踪您对该对象所做的更改。
您可以尝试使用DataContext.Attach，或者更好的是，为表单提供加载对象的原始数据上下文。