@msdn=http://search.microsoft.com/search/results.aspx?qu=$$$ @pinvoke=http://pinvoke.net/$$$.htm Summary: The TextOut API !!!!C# Signature: [DllImport("gdi32.dll", CharSet = CharSet.Auto)] static extern bool TextOut(IntPtr hdc, int nXStart, int nYStart, string lpString, int cbString); (Please see note for CharSet in tips) !!!!VB.NET Signature: <DllImport("gdi32")> _ Shared Function TextOut(ByVal hdc As IntPtr, ByVal x As Integer, _ ByVal y As Integer, ByVal textstring As String, _ ByVal charCount As Integer) As Boolean End Function !!!!Tips & Tricks: TextOut, unlike the Text property, have to be called every time Windows asks for a control to repaint. By using the Graphics.CopyFromScreen method one can copy the output of a Textout command and use that for repainting. Unlike graphics.drawstring, Textout can work with fonts other than True Type, Open Type, and PostScript fonts. If you have a font that's supported by Windows but not .net you can most likely use this command to draw it. [CharSet = CharSet.Auto] According to my experience this parameter should be used when using a LOGFONT structure and the CreateFontIndirect fuction, otherwise the selected font will not be displayed. All flags will be done (lfItalic, lfUnderline ...) but not the lfFaceName string. !!!!Sample Code: // Paste this at the beginning of your file if not present: using System.Drawing; using System.Runtime.InteropServices; //Create a class that subclass Control and paste these methods into it. //Then place the new control on a form. [DllImport("gdi32.dll")] static extern bool TextOut(IntPtr hdc, int nXStart, int nYStart, string lpString, int cbString); [DllImport("gdi32.dll")] static extern bool GetTextExtentPoint(IntPtr hdc, string lpString, int cbString, ref Size lpSize); [DllImport("gdi32.dll")] public static extern IntPtr SelectObject(IntPtr hdc, IntPtr hgdiobj); [DllImport("GDI32.dll")] public static extern bool DeleteObject(IntPtr objectHandle); #region Font protected override void OnKeyPress(KeyPressEventArgs e) { Text += e.KeyChar.ToString(); //Note, painting should not be done in the OnKeyPress method, instead: Refresh(); //You may want to meassure the string's size for layout purposes. using(Graphics g = base.CreateGraphics()) { //Do the GetHdc(), GetTextExtentPoint, etc, here. Remember that you have //to delete related objects such as fonts and call ReleaseHdc on graphics //afterwards. If you for some reason don't want to do this you can use a //SafeHandle (needs to be subclassed) which does this for you. //Remember to use HandleRef when appropriate. For instance if you create //a color that you set through SelectObject the .net garbage collector will //happily delete the color unless you refere to it after the drawing call or //use a HandleRef. //In this example we used the base class font and therefore need not worry //about the GC deleting the Font in mid drawing. //Also keep in mind that all graphics objects _you_ create must be disposed, //which is done through the using clause in this example. It can also be done //by calling g.Dispose() in a finally clause (to guarantee that it's executed) } } protected override void OnPaint(PaintEventArgs e) { IntPtr HDC = e.Graphics.GetHdc(); //We have to use SelectObject to set the font, color and other properties. IntPtr last_font = SelectObject(HDC, Font.ToHfont()); Size MeasureSize = new Size(0, 0); int y_pos = 0; int x_pos = 2; //Tasks such as these should not be done in the drawing loop as they //slow down the drawing. String[] lines = Text.Split(new char[] { '\n' }); try { //We draw out each line of text. for(int c=0; c < lines.Length; c++) { String line = lines[c]; TextOut(HDC, x_pos, y_pos, line, line.Length); //Unless you change the font, the line height never //changes so measuring the text at each draw call is //inefficient. Also it measure empty lines at 0 height //so pressing multiple enters will not move the text down. GetTextExtentPoint(HDC, line, line.Length, ref MeasureSize); y_pos += MeasureSize.Height; //You can use the MeasureSize.Width property to implement //word wrapping. } } finally { //Put here to make sure we don't get a memory leak. DeleteObject(SelectObject(HDC, last_font)); e.Graphics.ReleaseHdc(HDC); //Don't call dispose() on the Graphics object unless you createded it. } } !!!! Vb.net Sample: Imports System.Runtime.InteropServices Public Class Form1 Declare Function SetTextCharacterExtra Lib "gdi32" Alias "SetTextCharacterExtra" (ByVal hDC As Integer, ByVal nCharExtra As Integer) As Integer <DllImport("gdi32")> _ Private Shared Function TextOut(ByVal hdc As IntPtr, ByVal x As Integer, ByVal y As Integer, ByVal textstring As String, ByVal charCount As Integer) As Boolean End Function <DllImport("gdi32")> _ Private Shared Function SelectObject(ByVal hdc As IntPtr, ByVal hgdiobj As IntPtr) As IntPtr End Function <DllImport("gdi32")> _ Private Shared Function DeleteObject(ByVal objectHandle As IntPtr) As Boolean End Function <DllImport("gdi32")> _ Private Shared Function SetBkColor(ByVal hdc As IntPtr, ByVal crColor As Integer) As UInt32 End Function <DllImport("gdi32")> _ Private Shared Function SetTextColor(ByVal hdc As IntPtr, ByVal crColor As Integer) As UInt32 End Function Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Using G = Graphics.FromHwnd(Me.Handle) Using myFont As New System.Drawing.Font("Arial", 20, FontStyle.Regular, GraphicsUnit.Pixel) 'Regular Way Dim LeftEdge = 20 G.DrawString("Hello", myFont, Brushes.Red, LeftEdge, 40) 'If you want kerning Dim Kerning As Integer = 6 'I think this is twips Dim Hdc As IntPtr Dim FontPtr As IntPtr Try 'Grab the Graphic object's handle Hdc = G.GetHdc() 'Set the current GDI font FontPtr = SelectObject(Hdc, myFont.ToHfont()) 'Set the drawing surface background color SetBkColor(Hdc, ColorTranslator.ToWin32(Me.BackColor)) 'Set the text color SetTextColor(Hdc, ColorTranslator.ToWin32(Color.Red)) 'Set the kerning SetTextCharacterExtra(Hdc, Kerning) Dim Text = "Hello" 'Draw the text at (20,60), Kerning will be applied so reset the left edge to half of kerning TextOut(Hdc, LeftEdge + (Kerning \ 2), 60, Text, Text.Length) Catch ex As Exception Finally 'Release the font DeleteObject(FontPtr) 'Release the handle on the graphics object G.ReleaseHdc() End Try End Using End Using End Sub End Class !!!!Alternative Managed API: Graphics.DrawString Graphics.MeasureString Graphics.MeasureCharacterRanges Documentation: TextOut@msdn on MSDN
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