在DataGridView最下方通过paint显示一行相关数据

我们在用DataGridView显示数据的时候是否有时会觉得它的功能并不是十分的人性，比如我们想做一个统计所有数据的量或者一列数据的综合，总感到没有地方来呈现它们，其实我们那可以很好的利用DataGridView的paint方法来绘制一行”假”Row来显示，这样既节省空间又美观大方。



现在我们就开始做一个上面的例子吧!

首先我们要继承.net自带的强大的DataGridView

1. 提供一个枚举类型BottomAlign用来显示相关值排列的对齐方式(left,right,center),并且在类中定义一个BottomAlign类型的BottomAlignment属性

2. 重写DataGridView的OnPaint方法

具体代码如下:

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using System.Drawing;
using System.ComponentModel;

namespace RaxComponent
{
public enum BottomAlign { left, right, center }

public class RaxDataGridView : DataGridView
{
private BottomAlign _BottomAlignment = BottomAlign.left;
[Category("Rax")]
public BottomAlign BottomAlignment
{
get
{
return _BottomAlignment;
}
set
{
_BottomAlignment = value;
}
}

protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
Graphics g;
if (e == null)
{
g = Graphics.FromHwnd(this.Handle);
}
else
{
g = e.Graphics;
}
SolidBrush myBrush1 = new SolidBrush(SystemColors.Control);
SolidBrush myBrush2 = new SolidBrush(Color.IndianRed);
Pen pen1 = new Pen(Brushes.White, 1);
if (this.Rows.Count > 0 && this.Rows[this.Rows.Count - 1].Displayed)
{
int LocY = this.GetRowDisplayRectangle(this.Rows.Count - 1, true).Location.Y + this.Rows[this.Rows.Count - 1].Height;
//draw caption
g.FillRectangle(myBrush1, 2, LocY, this.RowHeadersWidth - 2, 23);
//caption's top line
g.DrawLine(pen1, new Point(2, LocY), new Point(this.RowHeadersWidth - 1, LocY));
// caption's left line
g.DrawLine(pen1, new Point(2, LocY), new Point(2, LocY + 23));

//draw cells
StringFormat sf = new StringFormat();
sf.Alignment = StringAlignment.Near;
sf.LineAlignment = StringAlignment.Near;

int cellLocX = this.RowHeadersWidth + 1;
int i = this.Columns.Count;
for (int j = 0; j < i; j++)
{
if (this.Columns[j].Displayed)
{
int cellTextLocX = cellLocX;
g.FillRectangle(myBrush2, cellLocX, LocY, this.GetColumnDisplayRectangle(j, false).Width - 1, 23);
#region DrawString
if (this.GetColumnDisplayRectangle(j, false).Width == this.Columns[j].Width)
{
int cellWidth = this.GetColumnDisplayRectangle(j, false).Width;
try
{
string strFmValue = this.Columns[j].DataPropertyName + "列相关值";
switch (this.BottomAlignment)
{
case BottomAlign.right:
cellTextLocX = cellTextLocX + cellWidth - (int)g.MeasureString(strFmValue, new Font(new FontFamily("Verdana"), 8), cellWidth).Width;
break;
case BottomAlign.center:
cellTextLocX = cellTextLocX + cellWidth / 2 - (int)(g.MeasureString(strFmValue, new Font(new FontFamily("Verdana"), 8), cellWidth).Width / 2);
break;
}
g.DrawString(strFmValue, new Font(new FontFamily("Verdana"), 8), Brushes.Black, cellTextLocX, LocY + 6, sf);
}
catch
{
g.DrawString("", new Font(new FontFamily("Verdana"), 8), Brushes.Black, cellTextLocX, LocY + 6, sf);
}
}
#endregion
cellLocX += this.GetColumnDisplayRectangle(j, false).Width;
}
}
// draw caption string
g.DrawString("Rax", new Font(new FontFamily("Verdana"), 8), Brushes.Black, 4, LocY + 6, sf);
}
}
}
}

(未经本人许可谢绝转载)