DataGridView 的重绘

             .net Winform 中的DataGridView 的外观有点难看。下面是重绘DataGridView的方法,可以重绘时参考:

1.重绘DataGridView 

protected override void Paint(
    Graphics graphics,
    Rectangle clipBounds,
    Rectangle cellBounds,
    int rowIndex,
    DataGridViewElementStates cellState,
    object value,
    object formattedValue,
    string errorText,
    DataGridViewCellStyle cellStyle,
    DataGridViewAdvancedBorderStyle advancedBorderStyle,
    DataGridViewPaintParts paintParts)
{
    // Call the base class method to paint the default cell appearance.
    base.Paint(graphics, clipBounds, cellBounds, rowIndex, cellState,
        value, formattedValue, errorText, cellStyle,
        advancedBorderStyle, paintParts);

    // Retrieve the client location of the mouse pointer.
    Point cursorPosition =
        this.DataGridView.PointToClient(Cursor.Position);

    // If the mouse pointer is over the current cell, draw a custom border.
    if (cellBounds.Contains(cursorPosition))
    {
        Rectangle newRect = new Rectangle(cellBounds.X + 1,
            cellBounds.Y + 1, cellBounds.Width - 4,
            cellBounds.Height - 4);
        graphics.DrawRectangle(Pens.Red, newRect);
    }
}

2.重绘DataGridView 的头部

protected override void OnCellPainting(DataGridViewCellPaintingEventArgs e)
        {
            base.OnCellPainting(e);

            if (e.ColumnIndex == -1 && e.RowIndex == -1)
            {
                using (LinearGradientBrush brush = new LinearGradientBrush(e.CellBounds, Color.LightGray,
                    Color.White, LinearGradientMode.ForwardDiagonal))
                {
                    e.Graphics.FillRectangle(brush, e.CellBounds);
                    Rectangle border = e.CellBounds;
                    border.Offset(new Point(-1, -1));
                    e.Graphics.DrawRectangle(Pens.Gray, border);
                }
                e.PaintContent(e.CellBounds);
                e.Handled = true;
            }
            else if (e.RowIndex == -1)
            {
                //标题行
                using (LinearGradientBrush brush = new LinearGradientBrush(e.CellBounds, Color.LightGray,
                    Color.White, LinearGradientMode.Vertical))
                {
                    e.Graphics.FillRectangle(brush, e.CellBounds);
                    Rectangle border = e.CellBounds;
                    border.Offset(new Point(-1, -1));
                    e.Graphics.DrawRectangle(Pens.Gray, border);
                }
                e.PaintContent(e.CellBounds);
                e.Handled = true;
            }
            else if (e.ColumnIndex == -1)
            {
                //标题列
                using (LinearGradientBrush brush = new LinearGradientBrush(e.CellBounds, Color.LightGray,
                    Color.White, LinearGradientMode.Horizontal))
                {
                    e.Graphics.FillRectangle(brush, e.CellBounds);
                    Rectangle border = e.CellBounds;
                    border.Offset(new Point(-1, -1));
                    e.Graphics.DrawRectangle(Pens.Gray, border);
                }
                e.PaintContent(e.CellBounds);
                e.Handled = true;
            }
        }

3.重绘实现合并单元格

#region"合并单元格的测试"
private int? nextrow = null;
private int? nextcol = null;
private void dataGridView1_CellFormatting(object sender, System.Windows.Forms.DataGridViewCellFormattingEventArgs e)
{
    if (this.dataGridView1.Columns["description"].Index == e.ColumnIndex && e.RowIndex >= 0)
    {
        if (this.nextcol != null & e.ColumnIndex == this.nextcol)
        {
            e.CellStyle.BackColor = Color.LightBlue;
            this.nextcol = null;
        }
        if (this.nextrow != null & e.RowIndex == nextrow)
        {
            e.CellStyle.BackColor = Color.LightPink;
            this.nextrow = null;
        }
        if (e.RowIndex != this.dataGridView1.RowCount - 1)
        {
            if (e.Value.ToString() == this.dataGridView1.Rows[e.RowIndex + 1].Cells[e.ColumnIndex].Value.ToString())
            {
                e.CellStyle.BackColor = Color.LightPink;
                nextrow = e.RowIndex + 1;
            }
        }
    }
    if (this.dataGridView1.Columns["name"].Index == e.ColumnIndex && e.RowIndex >= 0)
    {
        if (e.Value.ToString() == this.dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex + 1].Value.ToString())
        {
            e.CellStyle.BackColor = Color.LightBlue;
            nextcol = e.ColumnIndex + 1;
        }
    }
}
//==========================
       
//绘制单元格
private void dataGridView1_CellPainting(object sender, System.Windows.Forms.DataGridViewCellPaintingEventArgs e)
{

 

    //纵向合并
    if (this.dataGridView1.Columns["description"].Index == e.ColumnIndex && e.RowIndex >= 0)
    {

        using (
            Brush gridBrush = new SolidBrush(this.dataGridView1.GridColor),
            backColorBrush = new SolidBrush(e.CellStyle.BackColor))
        {
            using (Pen gridLinePen = new Pen(gridBrush))
            {
                // 擦除原单元格背景
                e.Graphics.FillRectangle(backColorBrush, e.CellBounds);
                绘制线条,这些线条是单元格相互间隔的区分线条,
                因为我们只对列name做处理,所以datagridview自己会处理左侧和上边缘的线条
                if (e.RowIndex != this.dataGridView1.RowCount - 1)
                {
                    if (e.Value.ToString() != this.dataGridView1.Rows[e.RowIndex + 1].Cells[e.ColumnIndex].Value.ToString())
                    {

                        e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left, e.CellBounds.Bottom - 1,
                        e.CellBounds.Right - 1, e.CellBounds.Bottom - 1);//下边缘的线
                        //绘制值
                        if (e.Value != null)
                        {
                            e.Graphics.DrawString((String)e.Value, e.CellStyle.Font,
                                Brushes.Crimson, e.CellBounds.X + 2,
                                e.CellBounds.Y + 2, StringFormat.GenericDefault);
                        }
                    }
                }
                else
                {
                    e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left, e.CellBounds.Bottom - 1,
                        e.CellBounds.Right - 1, e.CellBounds.Bottom - 1);//下边缘的线
                    //绘制值
                    if (e.Value != null)
                    {
                        e.Graphics.DrawString((String)e.Value, e.CellStyle.Font,
                            Brushes.Crimson, e.CellBounds.X + 2,
                            e.CellBounds.Y + 2, StringFormat.GenericDefault);
                    }
                }
                //右侧的线
                e.Graphics.DrawLine(gridLinePen, e.CellBounds.Right - 1,
                    e.CellBounds.Top, e.CellBounds.Right - 1,
                    e.CellBounds.Bottom - 1);

                e.Handled = true;
            }
        }
    }

    //横向合并
    if (this.dataGridView1.Columns["name"].Index == e.ColumnIndex && e.RowIndex >= 0)
    {

        using (
            Brush gridBrush = new SolidBrush(this.dataGridView1.GridColor),
            backColorBrush = new SolidBrush(e.CellStyle.BackColor))
        {
            using (Pen gridLinePen = new Pen(gridBrush))
            {
                // 擦除原单元格背景
                e.Graphics.FillRectangle(backColorBrush, e.CellBounds);

                if (e.Value.ToString() != this.dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex + 1].Value.ToString())
                {

                    //右侧的线
                    e.Graphics.DrawLine(gridLinePen, e.CellBounds.Right - 1, e.CellBounds.Top,
                        e.CellBounds.Right - 1, e.CellBounds.Bottom - 1);
                    //绘制值
                    if (e.Value != null)
                    {
                        e.Graphics.DrawString((String)e.Value, e.CellStyle.Font,
                            Brushes.Crimson, e.CellBounds.X + 2,
                            e.CellBounds.Y + 2, StringFormat.GenericDefault);
                    }
                }

                //下边缘的线
                e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left, e.CellBounds.Bottom - 1,
                                            e.CellBounds.Right - 1, e.CellBounds.Bottom - 1);
                e.Handled = true;
            }
        }

    }

}

#endregion


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