.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。