/// <summary>
/// Show a tool tip containing the text of the cell at the specified coordinates, but only if the text
/// doesn't fit into the cell.
/// </summary>
private string GetToolTipForTextColumn(int x, int y, DataGridCell hitCell,
System.Windows.Forms.DataGridTextBoxColumn columnStyle)
{
string cellText = string.Empty;
// Check whether the hit was within the text area of the cell, if possible.
DataGridTextBoxColumn customTextColumn = columnStyle as DataGridTextBoxColumn;
if (customTextColumn != null)
{
Rectangle textBounds = customTextColumn.GetTextBounds(hitCell);
if (textBounds.Contains(x, y))
{
cellText = GetTextForCell(hitCell, columnStyle);
}
}
else
{
cellText = GetTextForCell(hitCell, columnStyle);
}
// Only display the tooltip if we have the text and it doesn't fit into the cell.
if (cellText == null || (cellText.Length > 0 && DoesTextFitInCell(hitCell, cellText, columnStyle)))
{
cellText = string.Empty;
}
return(cellText);
}
private bool DoesTextFitInCell(DataGridCell cell, string text,
System.Windows.Forms.DataGridTextBoxColumn columnStyle)
{
Debug.Assert(text != null, "text != null");
// If the supplied column style is our own derived DataGridTextBoxColumn class ask it for the text
// bounds, otherwise use the cell bounds.
DataGridTextBoxColumn customColumnStyle = columnStyle as DataGridTextBoxColumn;
Rectangle textBounds = (customColumnStyle == null ? GetCellBounds(cell) :
customColumnStyle.GetTextBounds(cell));
SizeF size = new SizeF((float)textBounds.Width, (float)textBounds.Height);
StringFormat format = new StringFormat(StringFormatFlags.NoWrap);
int charsFitted;
int linesFilled;
CreateGraphics().MeasureString(text, Font, size, format, out charsFitted, out linesFilled);
return(charsFitted == text.Length);
}