public void AddCellRenderer(IDataGridViewCellRenderer cellRenderer)
{
if (cellRenderer == null)
{
Debug.Assert(false, "cellRenderer 为 null");
return;
}
if (_cellRenderers.Contains(cellRenderer))
{
Debug.Assert(false, "cellRenderer 已存在");
return;
}
_cellRenderers.Add(cellRenderer);
}
/// <summary>
/// 绘制行中的单元格
/// </summary>
/// <param name="g"></param>
/// <param name="bounds"></param>
/// <param name="value"></param>
/// <param name="state"></param>
private void DrawRowCell(Graphics g, Rectangle bounds, int rowIndex, int columnIndex, object value, DataGridViewElementStates state)
{
if (bounds == Rectangle.Empty)
{
return;
}
g.Clear(_theme.RowBackColor);
Rectangle contentBounds = bounds;
int contentBoundsX = contentBounds.X;
int contentBoundsY = contentBounds.Y;
int contentBoundsWidth = contentBounds.Width;
int contentBoundsHeight = contentBounds.Height;
bool selected = (state & DataGridViewElementStates.Selected) == DataGridViewElementStates.Selected;
#region 绘制选定或未选定情况下的单元格
if (selected)
{
Brush backBrush;
Pen borderPen;
if (_dataGridView.Focused)
{
backBrush = new LinearGradientBrush(contentBounds, _theme.RowSelectedBackColorStart, _theme.RowSelectedBackColorEnd,
LinearGradientMode.Vertical);
borderPen = new Pen(_theme.RowSelectedBorderColor);
}
else
{
backBrush = new LinearGradientBrush(contentBounds, _theme.RowUnFocusedSelectedColorStart, _theme.RowUnFocusedSelectedColorEnd,
LinearGradientMode.Vertical);
borderPen = new Pen(_theme.RowUnFocusedSelectedBorderColor);
}
DrawRowCell(g, columnIndex, bounds, backBrush, borderPen);
backBrush.Dispose();
borderPen.Dispose();
}
else
{
using (Brush backBrush = new SolidBrush(_theme.RowBackColor))
{
g.FillRectangle(backBrush, bounds);
}
}
#endregion
#region 绘制鼠标经过时的背景
if (_hoveredRow != null && rowIndex == _hoveredRow.Index)
{
Brush backBrush = new LinearGradientBrush(bounds, _theme.RowHoveredBackColorStart, _theme.RowHoveredBackColorEnd,
LinearGradientMode.Vertical);
Pen borderPen = new Pen(_theme.RowHoveredBorderColor);
DrawRowCell(g, columnIndex, bounds, backBrush, borderPen);
backBrush.Dispose();
borderPen.Dispose();
}
#endregion
#region 绘制单元格的内容部分，如文本，checkbox，或图像
if (value != null)
{
DataGridViewCell cell = _dataGridView[columnIndex, rowIndex];
IDataGridViewCellRenderer cellRenderer = GetCellRenderer(cell);
if (cellRenderer != null)
{
cellRenderer.Paint(g, _dataGridView.ClientRectangle, bounds, rowIndex, state, value,
cell.FormattedValue, cell.ErrorText, cell.Style);
}
//如果没有找到匹配的单元格渲染器，绘制内容的文本形式
else
{
string text = value.ToString();
SizeF textSize = g.MeasureString(text, _font);
RectangleF textBounds = new RectangleF();
textBounds.X = contentBoundsX + 2;
textBounds.Y = bounds.Y + (bounds.Height - textSize.Height) / 2;
textBounds.Width = bounds.Width - 4;
textBounds.Height = textSize.Height;
using (SolidBrush fontBrush = new SolidBrush(_theme.RowTextColor))
{
g.DrawString(value.ToString(), _dataGridView.Font, fontBrush, textBounds, _cellTextStringFormat);
}
}
}
#endregion
}
