问题
I made a program in which I wanted to manually update the Data Grid View. -I have a Method to Refresh the DGV by clearing it and then reinserting the data. -Using the designer, I made an event handler for the DGV's CellEndEdit. Inside the Event Handler, the data gets updated & the DGV's custom refreshing method is called.
While running the program, whenever I start editing a cell & end it by selecting another one, an exception is thrown:
InvalidOperationException Operation is not valid because it results in a reentrant call to the SetCurrentCellAddressCore function.
Visual C#'s debugger marks the line that clears the data : datagridview1.Rows.Clear();
If you'd like to reproduce the problem, Make a new windows form project with visual c#, put a DataGridView object on the form, and paste the following code for the Form1.cs:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace Error___DataGridView_Updating___Cell_endedit
{
public partial class Form1 : Form
{
// Objects
DataTable dt;
DataColumn colID;
DataColumn colName;
DataColumn colInfo;
// Constructor
public Form1()
{
InitializeComponent();
Initialize_dt();
InsertSampleData_dt();
Initialize_dataGridView1();
}
// Methods
private void Initialize_dt()
{
dt = new DataTable();
// Building Columns
// ID
colID = new DataColumn();
colID.ColumnName = "ID";
colID.DataType = typeof(int);
dt.Columns.Add(colID);
// Name
colName = new DataColumn();
colName.ColumnName = "Name";
colName.DataType = typeof(string);
dt.Columns.Add(colName);
//Info
colInfo = new DataColumn();
colInfo.ColumnName = "Info";
colInfo.DataType = typeof(string);
dt.Columns.Add(colInfo);
}
private void InsertSampleData_dt()
{
DataRow row;
// 0
row = dt.NewRow();
row["ID"] = 100;
row["Name"] = "AAAA";
row["Info"] = "First Record";
dt.Rows.Add(row);
//1
row = dt.NewRow();
row["ID"] = 101;
row["Name"] = "BBBB";
row["Info"] = "Second Record";
dt.Rows.Add(row);
//2
row = dt.NewRow();
row["ID"] = 102;
row["Name"] = "CCCC";
row["Info"] = "Third Record";
dt.Rows.Add(row);
}
private void Initialize_dataGridView1()
{
dataGridView1.AllowUserToAddRows = false;
// Data Grid Definitions
// Row Header
dataGridView1.RowHeadersWidthSizeMode = DataGridViewRowHeadersWidthSizeMode.DisableResizing;
dataGridView1.RowHeadersWidthSizeMode = DataGridViewRowHeadersWidthSizeMode.AutoSizeToAllHeaders;
// ColumnHeaders
dataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells;
// Building Columns
#region ID
{
DataGridViewColumn colSGID = new DataGridViewTextBoxColumn();
colSGID.Name = "ID";
colSGID.HeaderText = "#";
colSGID.ReadOnly = true;
colSGID.Visible = false;
colSGID.Resizable = DataGridViewTriState.False;
dataGridView1.Columns.Add(colSGID);
}
#endregion
#region Name
{
DataGridViewColumn colSGName = new DataGridViewTextBoxColumn();
colSGName.Name = "Name";
colSGName.HeaderText = "Name";
dataGridView1.Columns.Add(colSGName);
}
#endregion
#region Info
{
DataGridViewColumn colSGSubject = new DataGridViewTextBoxColumn();
colSGSubject.Name = "Info";
colSGSubject.HeaderText = "Description";
dataGridView1.Columns.Add(colSGSubject);
}
#endregion
Refresh_dataGridView1();
}
private void Refresh_dataGridView1()
{
int index;
dataGridView1.SuspendLayout();
dataGridView1.Rows.Clear();
//MessageBox.Show("Cleared Data. Rebuilding...");
foreach (DataRow row in dt.Rows)
{
index = dataGridView1.Rows.Add(new DataGridViewRow());
dataGridView1.Rows[index].Cells["ID"].Value = row["ID"];
dataGridView1.Rows[index].Cells["Name"].Value = row["Name"];
dataGridView1.Rows[index].Cells["Info"].Value = row["Info"];
//MessageBox.Show("row #" + index);
}
dataGridView1.ResumeLayout();
}
//Event Handlers
private void dataGridView1_CellEndEdit(object sender, DataGridViewCellEventArgs e)
{
bool toUpdate = false;
int id = (int)dataGridView1.Rows[e.RowIndex].Cells["ID"].Value;
string columnName = dataGridView1.Columns[e.ColumnIndex].Name;
string value = (string)dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Value;
if (value == null)
{
value = string.Empty;
}
switch (columnName)
{
case "Name":
if (value == string.Empty)
{
MessageBox.Show("Name Can't Be Empty!");
}
else
{
toUpdate = true;
}
break;
case "Info":
toUpdate = true;
break;
}
if (toUpdate)
{
foreach(DataRow row in dt.Rows)
{
if ( (int)row["ID"] == id)
{
row[columnName] = value;
}
}
Refresh_dataGridView1();
}
}
}
}
回答1:
There's an answer by Bruce.Zhou at MSDN forums. I posted here a snippet from it. Here also is the link to the original post.
private void dataGridView1_CellEndEdit(object sender, DataGridViewCellEventArgs e)
{
...................................................;
if (toUpdate)
{
foreach(DataRow row in dt.Rows)
{
if ( (int)row["ID"] == id)
{
row[columnName] = value;
}
}
this.BeginInvoke(new MethodInvoker(Refresh_dataGridView1));
}
}
...
When using this fix, whenever the new cell is selected, all the cells between it and the first cell (including) are selected. I am looking for a way to select only the new cell.
回答2:
i knocked my head against the keyboard for the last hour to solve this issue. here is my workaround: looking at the problem: when selecting another cell (or any control within the gridview) EndEdit is triggered.
apply the following check before applying your edit:
public void myGrid_EndEdit(object sender, DataGridViewCellEventArgs e)
{
if (!myGrid.Rows[e.RowIndex].Cells[e.ColumnIndex].Selected)
return;
//...rest of your code to apply edit below...
}
This should apply to any cell being edited.(thus edit is not applied when losing focus; Typing Enter would suffice to apply the edit)
回答3:
My work around was to capture the CellMouseDown event, and if the action was on a cell other than that being edited, then it issues the DataGridView.EndEdit(). Everything else works as expected.
来源：https://stackoverflow.com/questions/893752/invalidoperationexception-when-ending-editing-a-cell-moving-to-another-cell