问题
I have a winforms application that uses a datagridview. When I access the EditedFormattedValue of a cell while it is in edit mode, sometimes the whole cell turns black. Is this a feature of the datagridview, perhaps some sort of validation feature I need to turn off?
I have found a couple of other mentions of this problem while googling. None of the threads seem to know what the answer is either:
Here not calling Application.DoEvents solved the problem, but I am not calling DoEvents.
http://www.tek-tips.com/viewthread.cfm?qid=1277303&page=1
http://social.msdn.microsoft.com/Forums/en/winformsdatacontrols/thread/d9bf784d-617d-4a35-8125-fe8f67987fa2
Here no one knew why it was happening, but responders suggest setting the background color to white. That seems like a hack, and I'd like to know why this is happening. Also, changing the background color doesn't remove the black background for me.
Added by barlop
Note there is another cause of this, but since the title here is editedformattedvalue, i'll note this example first.
Example involving EditedFormattedValue as cause.
(when you double click the cell, (thus going into edit mode), it goes black)
namespace simpleblackdgv2
{
public partial class Form1 : Form
{
DataGridView dataGridView1 = new DataGridView();
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
// BUG IS THAT WHEN YOU DOUBLE CLICK A CELL, IT GOES BLACK
dataGridView1.Columns.Add("Column1", "Column1");
dataGridView1.Rows.Add(1);
dataGridView1.AllowUserToAddRows = false;
this.Controls.Add(dataGridView1);
dataGridView1.EditingControlShowing += DataGridView1_EditingControlShowing;
}
private void DataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
// doesn't work
string str = dataGridView1.CurrentCell.EditedFormattedValue.ToString();
}
}
}
On a related note this is another example of it going black, though not from editedformattedvalue (A previous edit to this question has a longer example, this is a simpler one that cuts to it quicker). The bug shows an issue when the general autosize settings are on - set to allcells, and a specific one is set to None, then it can get buggy depending on how you order the statements, which must be a bug. When setting any specific autosize, set the general to off.
Example Black related to resizing
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Diagnostics;
namespace blackdgvcellexample {
public partial class Form1 : Form {
DataGridView dataGridView1;
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
// autosize rows may be meaningless without that.
//dataGridView1.DefaultCellStyle.WrapMode = DataGridViewTriState.True;
dataGridView1 = new DataGridView();
this.Controls.Add(dataGridView1);
dataGridView1.Columns.Add("Column1", "Column1");
dataGridView1.Columns.Add("Column2", "Column2");
dataGridView1.Columns.Add("Column3", "Column3");
dataGridView1.AllowUserToAddRows = false;
dataGridView1.Rows.Add(5);
//dataGridView1.Rows.Add(1);
dataGridView1.EditingControlShowing += DataGridView1_EditingControlShowing;
}
private void DataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
dataGridView1.DefaultCellStyle.WrapMode = DataGridViewTriState.True;
//dataGridView1.Columns[0].AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells; //A
// dataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells; //B
// dataGridView1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.AllCells; //C
// B-Cols, C-rows
// A, ~B, ~C WORKS
// A,B, ~C WORKS
// A,~B,C WORKS
// A,B,C WORKS
// SO IT WAS THE ORDER OF THE LINES THAT MAKES A DIFFERENCE!!!!
// --- trying not turning any off
// dataGridView1.Columns[0].AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells; //A
// dataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells; //B
// dataGridView1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.AllCells; //C
// Cols, Rows, A BLACK FIRST CELL REST FINE
// rows, Cols, A BLACK FIRST CELL REST FINE
// cols,A,rows FINE
// rows,A,cols BLACK FIRST CELL REST FINE
// A, rows, cols BLACK FIRST CELL
// A, cols, rows FINE
// perhaps unnecessary to autoaize rows.
dataGridView1.Columns[0].AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells; //A
dataGridView1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.AllCells;
dataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells;
// this works
/*
dataGridView1.Columns[0].AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells; //A
dataGridView1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.AllCells;
*/
/*
* this works
dataGridView1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.AllCells;
dataGridView1.Columns[0].AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells; //A
*/
/*
doesn't work
dataGridView1.Columns[0].AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells; //A
dataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells;
*/
// doesn't work
// dataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells;
// dataGridView1.Columns[0].AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells; //A
// so don't mix them. ok
// this doesn't work
// dataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.None;
// dataGridView1.Columns[0].AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells; //A
// these 3 work in any order
// dataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.None;
// dataGridView1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.None;
// dataGridView1.Columns[0].AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells; //A
// don't mix them.
// if you are going to mix them, then turn the generals off and do specifics.
// this won't work
// dataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells;
// dataGridView1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.AllCells;
// dataGridView1.Columns[0].AutoSizeMode = DataGridViewAutoSizeColumnMode.None; //A
// this works, probably any order too.
/*
dataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.None;
dataGridView1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.None;
dataGridView1.Columns[0].AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells;
dataGridView1.Columns[1].AutoSizeMode = DataGridViewAutoSizeColumnMode.None;
dataGridView1.Columns[2].AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells;
*/
}
}
}
related- https://connect.microsoft.com/VisualStudio/feedback/details/2878864/datagridview-cell-goes-black
回答1:
Well, though I haven't been able to figure out why this is happening with the str=dataGridView1.CurrentCell.EditedFormattedValue, I found that using the str=dataGridView1.EditingControl.Text value gets the same value and doesn't mess with the cell formatting. So, I guess that solves my problem.
回答2:
The problem is now mentioned here
https://connect.microsoft.com/VisualStudio/feedback/details/2878864/datagridview-cell-goes-black
Besides the workaround mentioned by dvcolgan that works just for the case of editedformattedvalue.
There is a workaround from viorel mentioned at the ms bug link, that i've tested and works, which is to surround the code with
BeginInvoke( new Action( ( ) =>
{
. . .
} ) );
The above BeginInvoke technique works for both cases.
来源：https://stackoverflow.com/questions/3207777/datagridview-cell-turns-black-when-accessing-editedformattedvalue