private void Form1_Load(object sender, EventArgs e) { DataTable dt = new DataTable(); dt.Columns.Add("A"); dt.Columns.Add("B"); dt.Columns.Add("C"); dt.Columns.Add("D"); dt.Rows.Add(new object[] { "", "", "", "" }); dt.Rows.Add(new object[] { "", "", "", "" }); dt.Rows.Add(new object[] { "", "", "", "" }); this.dataGridView1.DataSource = dt; dataGridView1.AllowUserToAddRows = false;//禁止自动生成行 dataGridView1.ColumnHeadersVisible = false;//隐藏列头 }设置一个方法，通过调用这个方法来实现dataGridView单元格合并功能

可以编写如下的方法实现 DataGridView 单元格合并：

private void MergeCells()
{
    for (int i = 0; i < dataGridView1.Columns.Count; i++)
    {
        string columnName = dataGridView1.Columns[i].Name;
        int rowCount = dataGridView1.Rows.Count;
        int startIndex = 0;
        int mergeCount = 1;
        for (int j = 1; j < rowCount; j++)
        {
            DataGridViewCell prevCell = dataGridView1.Rows[j - 1].Cells[columnName];
            DataGridViewCell currCell = dataGridView1.Rows[j].Cells[columnName];
            if (prevCell.Value == currCell.Value)
            {
                mergeCount++;
            }
            else
            {
                if (mergeCount > 1)
                {
                    Rectangle rect = dataGridView1.GetCellDisplayRectangle(i, startIndex, 1, mergeCount);
                    for (int k = startIndex; k < startIndex + mergeCount; k++)
                    {
                        dataGridView1.Rows[k].Cells[columnName].Visible = false;
                    }
                    dataGridView1.Controls.Add(new Label()
                    {
                        Text = prevCell.Value.ToString(),
                        BorderStyle = BorderStyle.None,
                        BackColor = Color.White,
                        Location = rect.Location,
                        Size = rect.Size
                    });
                }
                startIndex = j;
                mergeCount = 1;
            }
        }
        if (mergeCount > 1)
        {
            Rectangle rect = dataGridView1.GetCellDisplayRectangle(i, startIndex, 1, mergeCount);
            for (int k = startIndex; k < startIndex + mergeCount; k++)
            {
                dataGridView1.Rows[k].Cells[columnName].Visible = false;
            }
            dataGridView1.Controls.Add(new Label()
            {
                Text = dataGridView1.Rows[startIndex].Cells[columnName].Value.ToString(),
                BorderStyle = BorderStyle.None,
                BackColor = Color.White,
                Location = rect.Location,
                Size = rect.Size
            });
        }
    }
}

在代码中，首先遍历 DataGridView 的每一列，然后对于每一列中相邻且相同的单元格进行合并。如果合并了多个单元格，则在合并后的区域中心添加一个 Label 控件，以显示合并后的值。最后将合并后的单元格设置为不可见即可。