c# - 表集的 UpdateAll 失败

Question

我有一个运行良好的 Windows 窗体项目，除了由设计器创建的保存按钮。保存项单击事件中的最后一条语句失败。这段代码是设计师生成的，我不完全理解。有谁知道是什么导致了错误？我希望它在导航离开记录时自动保存，并在可能的情况下使按钮成为单个记录保存。

    private void cUSTOMERBindingNavigatorSaveItem_Click(object sender, EventArgs e)
    {
        this.Validate();
        this.cUSTOMERBindingSource.EndEdit();
        dbCon = new SqlConnection(dbConString);
        SqlDataAdapter dbAdapter = new SqlDataAdapter();
        dbAdapter.SelectCommand = new SqlCommand("Select * From Customers");
        SqlCommandBuilder dbBldr = new SqlCommandBuilder();
        dbBldr.DataAdapter = dbAdapter;
        this.tableAdapterManager.UpdateAll(this.bML_WMS245GDataSet);
    }

异常详细信息和完整代码如下：

System.InvalidOperationException was unhandled
  HResult=-2146233079
  Message=Update requires a valid UpdateCommand when passed DataRow collection with modified rows.
  Source=Ballmill
  StackTrace:
       at Ballmill.BML_WMS245GDataSetTableAdapters.TableAdapterManager.UpdateAll(BML_WMS245GDataSet dataSet) in C:\Users\Jerry\documents\visual studio 2015\Projects\Ballmill\Ballmill\BML_WMS245GDataSet.Designer.cs:line 2102
       at Ballmill.Customer.cUSTOMERBindingNavigatorSaveItem_Click(Object sender, EventArgs e) in C:\Users\Jerry\documents\visual studio 2015\Projects\Ballmill\Ballmill\Customer.cs:line 29
       at System.Windows.Forms.ToolStripItem.RaiseEvent(Object key, EventArgs e)
       at System.Windows.Forms.ToolStripButton.OnClick(EventArgs e)
       at System.Windows.Forms.ToolStripItem.HandleClick(EventArgs e)
       at System.Windows.Forms.ToolStripItem.HandleMouseUp(MouseEventArgs e)
       at System.Windows.Forms.ToolStripItem.FireEventInteractive(EventArgs e, ToolStripItemEventType met)
       at System.Windows.Forms.ToolStripItem.FireEvent(EventArgs e, ToolStripItemEventType met)
       at System.Windows.Forms.ToolStrip.OnMouseUp(MouseEventArgs mea)
       at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
       at System.Windows.Forms.Control.WndProc(Message& m)
       at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
       at System.Windows.Forms.ToolStrip.WndProc(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
       at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.Run(Form mainForm)
       at Ballmill.Program.Main() in C:\Users\Jerry\documents\visual studio 2015\Projects\Ballmill\Ballmill\Program.cs:line 19
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: 


public partial class Customer : Form
{
    public string dbConString = "Data Source=localhost\\BALLMILL;Initial Catalog=Ballmill;Integrated Security=True";
    public SqlConnection dbCon = null;
    public SqlDataReader dbRdr = null;
    public SqlCommand dbCommand = null;

    public Customer()
    {
        InitializeComponent();
    }
    private void cUSTOMERBindingNavigatorSaveItem_Click(object sender, EventArgs e)
    {
        this.Validate();
        this.cUSTOMERBindingSource.EndEdit();
        dbCon = new SqlConnection(dbConString);
        SqlDataAdapter dbAdapter = new SqlDataAdapter();
        dbAdapter.SelectCommand = new SqlCommand("Select * From Customers");
        SqlCommandBuilder dbBldr = new SqlCommandBuilder();
        dbBldr.DataAdapter = dbAdapter;
        this.tableAdapterManager.UpdateAll(this.bML_WMS245GDataSet);
    }

    private void Customer_Load(object sender, EventArgs e)
    {
        this.cUSTOMERTableAdapter.Fill(this.bML_WMS245GDataSet.CUSTOMER);

        SqlConnection dbCon = new SqlConnection(dbConString);
        SqlDataReader rdrCustomers = null;
        try
        {
            dbCon.Open();
            SqlCommand sqlCustomers = new SqlCommand("SELECT CustomerCode FROM Customer", dbCon);
            rdrCustomers = sqlCustomers.ExecuteReader();
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message.ToString(), "Error accessing database");
            return;
        }

        while (rdrCustomers.Read())
        {
            listCustomers.Items.Add(rdrCustomers["CustomerCode"].ToString());
        }
    }

    private void listCustomers_SelectedIndexChanged(object sender, EventArgs e)
    {
        cUSTOMERBindingSource.Position = listCustomers.SelectedIndex;
    }
}