.NET WinForm中的DataGridView为程序开发提供了诸多的便利，我们不需要做许多额外的工作就可以获得一些基础功能，例如点击列标题排序、行选择功能、改变列宽和行宽，以及单元格内容的自动ToolTip功能等。但DataGridView给我们带来这些开发便利的同时也制造了一些小麻烦，例如对于单元格的自动ToolTip功能，我们如何才能自定义ToolTip提示框的样式呢？这里有一段代码可以帮助我们完成这个功能。
首先你需要在窗体上添加一个ToolTip控件，然后参考下面的代码给你的DataGridView添加CellMouseMove和MouseLeave事件，同时还需要给ToolTip控件添加Draw事件以定义ToolTip的具体呈现。
public
partial
class
MainForm : Form
{
private int cellColumnIndex = - 1 , cellRowIndex = - 1 ;
public MainForm()
{
InitializeComponent();
this .testDataGridView.ShowCellToolTips = false ;
this .toolTip.AutomaticDelay = 0 ;
this .toolTip.OwnerDraw = true ;
this .toolTip.ShowAlways = true ;
this .toolTip.ToolTipTitle = " Custom Tooltip: " ;
this .toolTip.UseAnimation = false ;
this .toolTip.UseFading = false ;
}
private void testDataGridView_CellMouseMove( object sender, DataGridViewCellMouseEventArgs e)
{
if (e.RowIndex < 0 || e.ColumnIndex < 0 )
{
return ;
}
this .toolTip.Hide( this .testDataGridView);
this .cellColumnIndex = e.ColumnIndex;
this .cellRowIndex = e.RowIndex;
if ( this .cellColumnIndex >= 0 && this .cellRowIndex >= 0 )
{
Point mousePos = PointToClient(MousePosition);
string tip = " Tip is " + this .testDataGridView[ this .cellColumnIndex, this .cellRowIndex].Value.ToString();
this .toolTip.Show(tip, this .testDataGridView, mousePos);
}
}
private void testDataGridView_MouseLeave( object sender, EventArgs e)
{
this .toolTip.Hide( this .testDataGridView);
}
private void toolTip_Draw( object sender, DrawToolTipEventArgs e)
{
e.Graphics.FillRectangle(Brushes.AliceBlue, e.Bounds);
e.Graphics.DrawRectangle(Pens.Chocolate, new Rectangle( 0 , 0 , e.Bounds.Width - 1 , e.Bounds.Height - 1 ));
e.Graphics.DrawString( this .toolTip.ToolTipTitle + e.ToolTipText, e.Font, Brushes.Red, e.Bounds);
}
}
{
private int cellColumnIndex = - 1 , cellRowIndex = - 1 ;
public MainForm()
{
InitializeComponent();
this .testDataGridView.ShowCellToolTips = false ;
this .toolTip.AutomaticDelay = 0 ;
this .toolTip.OwnerDraw = true ;
this .toolTip.ShowAlways = true ;
this .toolTip.ToolTipTitle = " Custom Tooltip: " ;
this .toolTip.UseAnimation = false ;
this .toolTip.UseFading = false ;
}
private void testDataGridView_CellMouseMove( object sender, DataGridViewCellMouseEventArgs e)
{
if (e.RowIndex < 0 || e.ColumnIndex < 0 )
{
return ;
}
this .toolTip.Hide( this .testDataGridView);
this .cellColumnIndex = e.ColumnIndex;
this .cellRowIndex = e.RowIndex;
if ( this .cellColumnIndex >= 0 && this .cellRowIndex >= 0 )
{
Point mousePos = PointToClient(MousePosition);
string tip = " Tip is " + this .testDataGridView[ this .cellColumnIndex, this .cellRowIndex].Value.ToString();
this .toolTip.Show(tip, this .testDataGridView, mousePos);
}
}
private void testDataGridView_MouseLeave( object sender, EventArgs e)
{
this .toolTip.Hide( this .testDataGridView);
}
private void toolTip_Draw( object sender, DrawToolTipEventArgs e)
{
e.Graphics.FillRectangle(Brushes.AliceBlue, e.Bounds);
e.Graphics.DrawRectangle(Pens.Chocolate, new Rectangle( 0 , 0 , e.Bounds.Width - 1 , e.Bounds.Height - 1 ));
e.Graphics.DrawString( this .toolTip.ToolTipTitle + e.ToolTipText, e.Font, Brushes.Red, e.Bounds);
}
}
testDataGridView是DataGridView的ID，toolTip是ToolTip的ID。