How to prevent going to next row after editing a DataGridViewTextBoxColumn and pressing EnterKey?

Question

I'm working on a program with DataGridViews. In one DatagridView there is a DataGridViewTextBoxColumn, which is enabled to be edited by the user. When the user is done with typing the numbers into it, he presses ENTER on the keyboard. Now the DataGridView does all its Events, and after all Events, the last thing is the problem.

Everything is done, and Windows is going to Select the next DataGridViewRow, and I'm not able to prevent this.

I tried

if (e.KeyData == Keys.Enter) e.SuppressKeyPress = true; // or e.Handled 

in nearly every event I found. Sadly I was only able to Prevent the ENTER key when the DataGridViewTextBoxColumn is not in edit mode.

Heres my methode t find the ENTER while in Editing

Adding the Event

private void dgr_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
    e.Control.KeyPress += new KeyPressEventHandler(dgr_KeyPress_NumericTester);
}

And this is the event to accept numeric input only.

private void dgr_KeyPress_NumericTester(object sender, KeyPressEventArgs e)
{
    if (!Char.IsDigit(e.KeyChar) && e.KeyChar != 8) e.Handled = true;
}

To explain in detail:

When the user enters a Value, that has some dependings, I would like to give another control the focus, so he is used to correct the dependings.

I also tried it with DependingControl.Focus() but the last "enter" is going to be the last thing on the view.

Does someone know how to prevent this?

Solution 1

Well, I managed to get something working that does what you want (or at least does the hard part, I think you have already done most of the other stuff) but the solution makes my skin crawl.

What I ended up with to "cancel" the enter key event when editing a cell as to use a mixture of the CellEndEdit event and the SelectionChanged event.

I introduced a couple of class level fields that store some state - in particular what row we are in at the end of editing a cell and whether we are stopping a selection changed.

The code looks like this:

public partial class Form1 : Form
{
    private int currentRow;
    private bool resetRow = false;

    public Form1()
    {
        InitializeComponent();

        // deleted out all the binding code of the grid to focus on the interesting stuff

        dataGridView1.CellEndEdit += new DataGridViewCellEventHandler(dataGridView1_CellEndEdit);

        // Use the DataBindingComplete event to attack the SelectionChanged, 
        // avoiding infinite loops and other nastiness.
        dataGridView1.DataBindingComplete += new DataGridViewBindingCompleteEventHandler(dataGridView1_DataBindingComplete);
    }

    void dataGridView1_SelectionChanged(object sender, EventArgs e)
    {
        if (resetRow)
        {
            resetRow = false;
            dataGridView1.CurrentCell = dataGridView1.Rows[currentRow].Cells[0];          
        }
    }

    void dataGridView1_CellEndEdit(object sender, DataGridViewCellEventArgs e)
    {
        resetRow = true;
        currentRow = e.RowIndex;
    }

    void dataGridView1_DataBindingComplete(object sender, DataGridViewBindingCompleteEventArgs e)
    {
        dataGridView1.SelectionChanged += new EventHandler(dataGridView1_SelectionChanged);
    }
} 

You'll want to test this thoroughly to make sure it does exactly what you need. I only checked to see that it does stop a row change when pressing enter out of an editing control.

As I said - I'm not too happy with needing to do something like this - it feels quite brittle, and also like it could have weird side effects. But if you must have this behaviour, and you test it well I think this is the only way to do what you want.

Solution 2

I tried this for changing the Enter behaviour for your Grid by inheriting a customcolumn from Textbox column and overriding the below event

protected override bool ProcessDialogKey(Keys keyData)
{
    if (keyData == Keys.Enter)
       return base.ProcessDialogKey(Keys.Tab);
    else
       return base.ProcessDialogKey(keyData);
}

So instead of the Enter Key being sent it emulates the action for Tab which will move to the next cell. Hope this helps

Solution 3

Private Sub DataGridView1_KeyDown(sender As Object, e As KeyEventArgs) Handles DataGridView1.KeyDown
    If e.KeyData = Keys.Enter Then e.Handled = True
End Sub

It's just a workaround, not a real solution, but it works.

Solution 4

You can do it simply....

1...Create the KeyDown Event for that grid view.(Go to properties on the gridview and double click the KeyDown event).

2...Past this code -

if(e.KeyData == Keys.Enter)
{
  e.Handled = true;
}

3...Finally its look like this.

private void dgvSearchResults_KeyDown(object sender, KeyEventArgs e)
{
  if (e.KeyData == Keys.Enter)
   {
    e.Handled = true;
   }
}

4..Run the program and see.

Solution 5

I know that this question was asked since long time ago but the answer may be useful for those who search in future i hope so. the best solution is to use your custom column and for textbox its easy because we will take advantage of the built in classes

class Native
{
    public const uint WM_KEYDOWN = 0x100;
    [DllImport("user32.dll")]
    public static extern bool PostMessage(IntPtr hWnd, UInt32 Msg, Int32 wParam, Int32 lParam);
}
//the column that will be added to dgv
public class CustomTextBoxColumn : DataGridViewColumn
{
    public CustomTextBoxColumn() : base(new CustomTextCell()) { }
    public override DataGridViewCell CellTemplate
    {
        get { return base.CellTemplate; }
        set
        {
            if (value != null && !value.GetType().IsAssignableFrom(typeof(CustomTextCell)))
            {
                throw new InvalidCastException("Must be a CustomTextCell");
            }
            base.CellTemplate = value;
        }
    }
}
//the cell used in the previous column
public class CustomTextCell : DataGridViewTextBoxCell
{
    public override Type EditType
    {
        get { return typeof(CustomTextBoxEditingControl); }
    }
}
//the edit control that will take data from user
public class CustomTextBoxEditingControl : DataGridViewTextBoxEditingControl
{
    protected override void WndProc(ref Message m)
    {
        //we need to handle the keydown event
        if (m.Msg == Native.WM_KEYDOWN)
        {
            if((ModifierKeys&Keys.Shift)==0)//make sure that user isn't entering new line in case of warping is set to true
            {
                Keys key=(Keys)m.WParam;
                if (key == Keys.Enter)
                {
                    if (this.EditingControlDataGridView != null)
                    {
                        if(this.EditingControlDataGridView.IsHandleCreated)
                        {
                            //sent message to parent dvg
                            Native.PostMessage(this.EditingControlDataGridView.Handle, (uint)m.Msg, m.WParam.ToInt32(), m.LParam.ToInt32());
                            m.Result = IntPtr.Zero;
                        }
                        return;
                    }
                }
            }
        }
        base.WndProc(ref m);
    }
}

then we come to the dgv itself i used a new class derived from DataGridView and added my columns and handled the enter key from the wndproc also

void Initialize()
{
    CustomTextBoxColumn colText = new CustomTextBoxColumn();
    colText.DataPropertyName = colText.Name = columnTextName;
    colText.HeaderText = columnTextAlias;
    colText.DefaultCellStyle.WrapMode = DataGridViewTriState.True;
    this.Columns.Add(colText);
    DataGridViewTextBoxColumn colText2 = new DataGridViewTextBoxColumn();
    colText2.DataPropertyName = colText2.Name = columnText2Name;
    colText2.HeaderText = columnText2Alias;
    colText2.DefaultCellStyle.WrapMode = DataGridViewTriState.False;
    this.Columns.Add(colText2);
}
protected override void WndProc(ref Message m)
{
    //the enter key is sent by edit control
    if (m.Msg == Native.WM_KEYDOWN)
    {
        if ((ModifierKeys & Keys.Shift) == 0)
        {
            Keys key = (Keys)m.WParam;
            if (key == Keys.Enter)
            {
                MoveToNextCell();
                m.Result = IntPtr.Zero;
                return;
            }
        }
    }

    base.WndProc(ref m);
}

//move the focus to the next cell in same row or to the first cell in next row then begin editing
public void MoveToNextCell()
{
    int CurrentColumn, CurrentRow;
    CurrentColumn = this.CurrentCell.ColumnIndex;
    CurrentRow = this.CurrentCell.RowIndex;
    if (CurrentColumn == this.Columns.Count - 1 && CurrentRow != this.Rows.Count - 1)
    {
        this.CurrentCell = Rows[CurrentRow + 1].Cells[1];//0 index is for No and readonly
        this.BeginEdit(false);
    }
    else if(CurrentRow != this.Rows.Count - 1)
    {
        base.ProcessDataGridViewKey(new KeyEventArgs(Keys.Tab));
        this.BeginEdit(false);
    }
}

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Comments

[Max]

This is working fine for me. Just one small bug when I'm trying to leave a DataGridViewCheckBoxCell i must not set resetRow, becourse it will jail my focus in the CheckBox. if (dataGridView1.CurrentCell is DataGridViewCheckBoxCell) resetRow = false; I was working with SelectedRow instead of changing the CurrentCell property, and this was not working well in my test... now its fine, thx a lot for this!

[Max]

Also a great way. Thanks for this too!