右键单击 DataGridView 的列标题时，如何正确定位上下文菜单？

Question

I would like to extended DataGridView to add a second ContextMenu which to select what columns are visible in the gird. The new ContextMenu will be displayed on right click of a column's header.

I am having difficulty get the correct horizontal position to show the context menu. How can I correct this?

public partial class Form1 : Form
{
    DataGridView dataGrid;
    ContextMenuStrip contextMenuStrip;        

    public Form1()
    {
        InitializeComponent();

        dataGrid = new DataGridView();
        Controls.Add(dataGrid);
        dataGrid.Dock = System.Windows.Forms.DockStyle.Fill;
        dataGrid.ColumnHeaderMouseClick += new System.Windows.Forms.DataGridViewCellMouseEventHandler(ColumnHeaderMouseClick);
        dataGrid.DataSource = new Dictionary<string, string>().ToList();

        contextMenuStrip = new ContextMenuStrip();
        contextMenuStrip.Items.Add("foo");
        contextMenuStrip.Items.Add("bar");
    }

    private void ColumnHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e)
    {
        if (e.Button == System.Windows.Forms.MouseButtons.Right)
        {
            contextMenuStrip.Show(PointToScreen(e.Location));
        }
    }
}

Answer 1

Here is a very simple way to make context menu appear where you right-click it.

Handle the event ColumnHeaderMouseClick

private void grid_ColumnHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e) 
{
  if (e.Button == System.Windows.Forms.MouseButtons.Right)
    contextMenuHeader.Show(Cursor.Position);
}

contextMenuHeader is a ContextMenuStrip that can be defined in the Designer view or at runtime.

Answer 2

要获得鼠标光标的坐标，您可以这样做。

ContextMenu.Show(this, myDataGridView.PointToClient(Cursor.Position)); 

Answer 3

Have you tried using the Show overload that accepts a control and a position?

For example:

contextMenuStrip.Show(dataGrid, e.Location);

Edit: Full example

public partial class Form1 : Form
{
    DataGridView dataGrid;
    ContextMenuStrip contextMenuStrip;        

    public Form1()
    {
        InitializeComponent();

        dataGrid = new DataGridView();
        Controls.Add(dataGrid);
        dataGrid.Dock = System.Windows.Forms.DockStyle.Fill;
        dataGrid.MouseDown += MouseDown;
        dataGrid.DataSource = new Dictionary<string, string>().ToList();

        contextMenuStrip = new ContextMenuStrip();
        contextMenuStrip.Items.Add("foo");
        contextMenuStrip.Items.Add("bar");
    }

    private void MouseDown(object sender, MouseEventArgs e)
    {
        if (e.Button == System.Windows.Forms.MouseButtons.Right)
        {
            if (dataGrid.HitTest(e.X, e.Y).Type == DataGridViewHitTestType.ColumnHeader)
            {
                contextMenuStrip.Show(dataGrid, e.Location);
            }
        }
    }
}

Answer 4

The position returned is relative to the cell. So we have to add that offset.

    private void grdView_CellMouseClick(object sender, DataGridViewCellMouseEventArgs e)
    {
        if (e.Button == MouseButtons.Right)
        {
            var pos = ((DataGridView)sender).GetCellDisplayRectangle(e.ColumnIndex, 
            e.RowIndex, false).Location;
            pos.X += e.X;
            pos.Y += e.Y;
            contextMenuStrip.Show((DataGridView)sender,pos);
        }
    }

Answer 5

e.Location does not show the popup menu at the correct coordinates, instead just use the MousePosition property as follows:

ContextMenuStrip.Show(MousePosition)

or, explicitely

ContextMenuStrip.Show(Control.MousePosition)

Answer 6

You were nearly right. You just need to the apply the PointToScreen method to the calling control:

private void ColumnHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e)
{
    if (e.Button == System.Windows.Forms.MouseButtons.Right)
    {
        contextMenuStrip.Show(((DataGridView)sender).PointToScreen(e.Location));
    }
}

I think this is the most elegant solution, because it uses only the ColumnHeaderMouseClick arguments and not Cursor.Position .

Answer 7

Calling Show twice will get you the exact location of the cursor. This answer is for those whom are unable to get the result with all above answers.

private void MouseDown(object sender, MouseEventArgs e)
{
    if (e.Button == System.Windows.Forms.MouseButtons.Right)
    {
        contextMenuStrip.Show(dataGrid, e.Location));
        contextMenuStrip.Show(Cursor.Position);
    }
}

Answer 8

最后这对我有用。

ContextMenu.Show(myDataGridView, myDataGridView.PointToClient(Cursor.Position)); 

Answer 9

Where I was going wrong was that DataGridViewCellMouseEventArgs returns the location/x,y of where the mouse clicked within the column header. Instead I need to use HitTest in the grid's MouseDown event for a hit on the column headers and then convert the position of the hit from the gird co-ordinates to the screen co-ordinates.

public partial class Form1 : Form
{
    DataGridView dataGrid;
    ContextMenuStrip contextMenuStrip;        

    public Form1()
    {
        InitializeComponent();

        dataGrid = new DataGridView();
        Controls.Add(dataGrid);
        dataGrid.Dock = System.Windows.Forms.DockStyle.Fill;
        //dataGrid.ColumnHeaderMouseClick += ColumnHeaderMouseClick;
        dataGrid.MouseDown += MouseDown;
        dataGrid.DataSource = new Dictionary<string, string>().ToList();

        contextMenuStrip = new ContextMenuStrip();
        contextMenuStrip.Items.Add("foo");
        contextMenuStrip.Items.Add("bar");
    }

    private void ColumnHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e)
    {
        if (e.Button == System.Windows.Forms.MouseButtons.Right)
        {
            contextMenuStrip.Show(PointToScreen(e.Location));
        }
    }

    private void MouseDown(object sender, MouseEventArgs e)
    {
        if (e.Button == System.Windows.Forms.MouseButtons.Right)
        {
            if (dataGrid.HitTest(e.X, e.Y).Type == DataGridViewHitTestType.ColumnHeader)
            {
                contextMenuStrip.Show(dataGrid.PointToScreen(e.Location));
            }
        }
    }
}