FAQ´S del foro de Net

[freegirl]

Tema: Windows Forms
Pregunta: Como visualizar todo el texto en la celda del datagrid, no sólo en modo edición.
Respuesta:

1) Crear una clase:

Class DataGridTextBoxColumnWrap
Inherits DataGridTextBoxColumn

Protected Overloads Overrides Sub Paint(ByVal g As System.Drawing.Graphics, _
ByVal bounds As System.Drawing.Rectangle, _
ByVal source As System.Windows.Forms.CurrencyManager, _
ByVal rowNum As Integer, _
ByVal backBrush As System.Drawing.Brush, _
ByVal foreBrush As System.Drawing.Brush, _
ByVal alignToRight As Boolean)

Dim stringSize As SizeF
Dim stringFont As Font
Dim columnWidth As Integer
Dim stringValue As String
Dim stringDisplay As String
Dim stringYCoord As Single
Dim stringHeight As Single
Dim stringArray As ArrayList
Dim intStringLoop As Integer

g.FillRectangle(backBrush, bounds) 'Paint the rectangle for the cell using the backBrush
stringFont = Me.DataGridTableStyle.DataGrid.Font 'Get the font used by the column(style)
columnWidth = bounds.Width 'Get the width of the column

stringSize = g.MeasureString("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefg hijklmnopqrstuvwxyz1234567890", stringFont)
stringHeight = stringSize.Height
stringValue = GetText(source, rowNum) 'Get the text to be displayed in the cell
stringArray = GetArrayList(g, stringValue, stringFont, columnWidth)

For intStringLoop = 0 To stringArray.Count - 1
stringDisplay = CType(stringArray.Item(intStringLoop), String)
stringYCoord = bounds.Y + (intStringLoop * stringHeight)
g.DrawString(stringDisplay, stringFont, foreBrush, bounds.X, stringYCoord)
Next

End Sub
Public Sub New()
' Initialise the object and set its default properities
MyBase.New()
Me.NullText = ""
Me.ReadOnly = True
End Sub

Protected Overloads Overrides Sub Edit(ByVal source As CurrencyManager, ByVal rowNum As Integer, ByVal bounds As Rectangle, ByVal readOnly1 As Boolean, ByVal instantText As String, ByVal cellIsVisible As Boolean)
' This particular column will always be readonly and non-editable - therefore do not pass the event over
Return
End Sub
#Region "Helper Methods"
Function GetText(ByVal source As System.Windows.Forms.CurrencyManager, _
ByVal rowNum As Integer) As String

Dim objValue As Object = GetColumnValueAtRow(source, rowNum)
If objValue Is System.DBNull.Value Then
Return Me.NullText
Else
Return CType(objValue, String)
End If
End Function

Function GetArrayList(ByVal g As Graphics, ByVal stringValue As String, _
ByVal stringFont As Font, ByVal columnWidth As Integer) As ArrayList
Dim intCurrentChar As Integer
Dim stringCurrentChar As String
Dim stringDisplay As String
Dim intSpace As Integer
Dim stringSize As SizeF
Dim stringArray As New ArrayList


Do Until stringValue = ""
For intCurrentChar = 0 To stringValue.Length - 1
stringCurrentChar = stringValue.Substring(intCurrentChar, 1)
stringSize = g.MeasureString(stringDisplay & stringCurrentChar, stringFont)
If stringSize.Width <= columnWidth Then
stringDisplay &= stringCurrentChar
If intCurrentChar = stringValue.Length - 1 Then
stringArray.Add(stringDisplay)
stringDisplay = ""
stringValue = ""
Exit For
End If
Else
'Figure out where the first space preceding this location is...
intSpace = stringDisplay.LastIndexOf(" ")
If intSpace >= 0 Then
'we found the last space
intCurrentChar = intSpace + 1
stringDisplay = stringDisplay.Substring(0, intSpace + 1)
stringArray.Add(stringDisplay)
stringDisplay = ""
stringValue = stringValue.Substring(intCurrentChar)
Exit For
Else

stringArray.Add(stringDisplay)
stringDisplay = ""
stringValue = stringValue.Substring(intCurrentChar)
Exit For
End If
End If
Next
Loop

Return stringArray
End Function
#End Region

End Class

2) usarlo en nuestro estilo creado:

Dim tb4 As DataGridTextBoxColumnWrap
tb4 = New DataGridTextBoxColumnWrap
tb4.HeaderText = "Item Description"
tb4.MappingName = "text"
tb4.NullText = ""
tb4.Width = 140
tb4.ReadOnly = True
ts.GridColumnStyles.Add(tb4)