private void dataGridView1_MouseDown(object sender,MouseEventArgs e)
    {
        if (e.Button == MouseButtons.Left)
        {
            DataGridView.HitTestInfo info = dataGridView1.HitTest(e.X,e.Y);
            if (info.RowIndex >= 0)
            {
                if (info.RowIndex >= 0 && info.ColumnIndex >= 0)
                {
                    string text = (String)
                           dataGridView1.Rows[info.RowIndex].Cells[info.ColumnIndex].Value;
                    if (text != null)
                        dataGridView1.DoDragDrop(text,DragDropEffects.Copy);
                }
            }
        }
    }

     private void dataGridView2_DragDrop(object sender,DragEventArgs e)
    {
        string cellvalue=e.Data.GetData(typeof(string)) as string;
        Point cursorLocation=this.PointToClient(new Point(e.X,e.Y));

        System.Windows.Forms.DataGridView.HitTestInfo hittest= dataGridView2.HitTest(cursorLocation.X,cursorLocation.Y);
        if (hittest.ColumnIndex != -1
            && hittest.RowIndex != -1)
            dataGridView2[hittest.ColumnIndex,hittest.RowIndex].Value = cellvalue;
    }

    private void dataGridView2_DragEnter(object sender,DragEventArgs e)
    {
        e.Effect = DragDropEffects.Copy;
    }

// dataGridView1
        // 
        this.dataGridView1.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
        this.dataGridView1.Location = new System.Drawing.Point(12,12);
        this.dataGridView1.Name = "dataGridView1";
        this.dataGridView1.Size = new System.Drawing.Size(299,150);
        this.dataGridView1.TabIndex = 0;
        this.dataGridView1.MouseDown += new System.Windows.Forms.MouseEventHandler(this.dataGridView1_MouseDown);
        // 
        // dataGridView2
        // 
        this.dataGridView2.AllowDrop = true;
        this.dataGridView2.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
        this.dataGridView2.Columns.AddRange(new System.Windows.Forms.DataGridViewColumn[] {
        this.Column1,this.Column2});
        this.dataGridView2.Location = new System.Drawing.Point(353,141);
        this.dataGridView2.Name = "dataGridView2";
        this.dataGridView2.Size = new System.Drawing.Size(240,150);
        this.dataGridView2.TabIndex = 5;
        this.dataGridView2.DragDrop += new System.Windows.Forms.DragEventHandler(this.dataGridView2_DragDrop);
        this.dataGridView2.DragEnter += new System.Windows.Forms.DragEventHandler(this.dataGridView2_DragEnter);
        //

解决方法@H_403_12@

您可以使用以下代码.我已经测试了它,它正在将单元数据从一个datagridview复制到另一个datagridview.

private void dataGridView2_DragEnter(object sender,DragEventArgs e)
    {
        e.Effect = DragDropEffects.Copy;
    }

    /* Drag & Drop */
    private Rectangle dragBoxFromMouseDown;
    private object valueFromMouseDown;
    private void dataGridView1_MouseMove(object sender,MouseEventArgs e)
    {
        if ((e.Button & MouseButtons.Left) == MouseButtons.Left)
        {
            // If the mouse moves outside the rectangle,start the drag.
            if (dragBoxFromMouseDown != Rectangle.Empty && !dragBoxFromMouseDown.Contains(e.X,e.Y))
            {
                // Proceed with the drag and drop,passing in the list item.                    
                DragDropEffects dropEffect = dataGridView1.DoDragDrop(valueFromMouseDown,DragDropEffects.Copy);
            }
        }
    }

    private void dataGridView1_MouseDown(object sender,MouseEventArgs e)
    {
        // Get the index of the item the mouse is below.
        var hittestInfo = dataGridView1.HitTest(e.X,e.Y);

        if (hittestInfo.RowIndex != -1 && hittestInfo.ColumnIndex != -1)
        {
            valueFromMouseDown = dataGridView1.Rows[hittestInfo.RowIndex].Cells[hittestInfo.ColumnIndex].Value;
            if (valueFromMouseDown != null)
            {
                // Remember the point where the mouse down occurred. 
                // The DragSize indicates the size that the mouse can move 
                // before a drag event should be started.                
                Size dragSize = SystemInformation.DragSize;

                // Create a rectangle using the DragSize,with the mouse position being
                // at the center of the rectangle.
                dragBoxFromMouseDown = new Rectangle(new Point(e.X - (dragSize.Width / 2),e.Y - (dragSize.Height / 2)),dragSize);
            }
        }
        else
            // Reset the rectangle if the mouse is not over an item in the ListBox.
            dragBoxFromMouseDown = Rectangle.Empty;
    }

    private void dataGridView2_DragOver(object sender,DragEventArgs e)
    {
        e.Effect = DragDropEffects.Copy;
    }

    private void dataGridView2_DragDrop(object sender,DragEventArgs e)
    {
        // The mouse locations are relative to the screen,so they must be 
        // converted to client coordinates.
        Point clientPoint = dataGridView2.PointToClient(new Point(e.X,e.Y));

        // If the drag operation was a copy then add the row to the other control.
        if (e.Effect == DragDropEffects.Copy)
        {
            string cellvalue = e.Data.GetData(typeof(string)) as string;
            var hittest = dataGridView2.HitTest(clientPoint.X,clientPoint.Y);
            if (hittest.ColumnIndex != -1
                && hittest.RowIndex != -1)
                dataGridView2[hittest.ColumnIndex,hittest.RowIndex].Value = cellvalue;

        }
    }