GetTextHeight(String,Single,Boolean) Method

In This Topic

Calculates the height of the font you have specified, expressed in the current units used in the loaded PDF document.

You can use the GetMeasurementUnit method to determine the currently defined units and you can also use the SetMeasurementUnit method to reset the units according to your preference.

Syntax

Visual Basic
C#
Delphi
JScript
Managed Extensions for C++
C++/CLI

'Declaration
 
Public Overloads Function GetTextHeight( _
   ByVal FontResName As String, _
   ByVal TextSize As Single, _
   ByVal UseFontBox As Boolean _
) As Single

public float GetTextHeight( 
   string FontResName,
   float TextSize,
   bool UseFontBox
)

public function GetTextHeight( 
    FontResName: String;
    TextSize: Single;
    UseFontBox: Boolean
): Single;

public function GetTextHeight( 
   FontResName : String,
   TextSize : float,
   UseFontBox : boolean
) : float;

public: float GetTextHeight( 
   string* FontResName,
   float TextSize,
   bool UseFontBox
)

public:
float GetTextHeight( 
   String^ FontResName,
   float TextSize,
   bool UseFontBox
)

Parameters

FontResName: The resource name of the font you prefer.
You can easily obtain this name using the AddStandardFont method or any of the AddTrueTypeFont...() methods. For further assistance, please see the section Fonts of the GdPicturePDF class in the Reference Guide.
TextSize: The size of the text (the font size actually), in points.
UseFontBox: Set this parameter to true if you want to determine the font height by using the font boundary box. It is an imaginary box that encloses all glyphs from the font, usually as tightly as possible. It is represented by four parameters.
Set this parameter to false if you want to determine the font height by using the font's ascent and descent properties. The ascent property is the distance from the baseline to the highest grid coordinate used to place an outline point, the descent property to the lowest grid coordinate.

Return Value

The height of the specified font, expressed in the current units specified by the SetMeasurementUnit method.

The GetStat method can be subsequently used to determine if this method has been successful.

Remarks

This method is only allowed for use with non-encrypted documents.

It is recommend to use the GetStat method to identify the specific reason for the method's failure, if any. For example, if the currently loaded PDF document does not contain any page, this method will fail.

Just to remind you that 1 point is equivalent to 1/72 of an inch.

Example

How to determine the height of the standard Times-Roman font with and without respect to the font boundary box.

VB.NET
C#

Dim caption As String = "Example: GetTextHeight"
Dim gdpicturePDF As New GdPicturePDF()
Dim status As GdPictureStatus = gdpicturePDF.LoadFromFile("test.pdf", False)
If status = GdPictureStatus.OK Then
    gdpicturePDF.SetMeasurementUnit(PdfMeasurementUnit.PdfMeasurementUnitCentimeter)
    status = gdpicturePDF.GetStat()
    If status = GdPictureStatus.OK Then
        Dim fontName As String = gdpicturePDF.AddStandardFont(PdfStandardFont.PdfStandardFontTimesRoman)
        If gdpicturePDF.GetStat() = GdPictureStatus.OK Then
            Dim message As String = ""
            Dim height As Single = gdpicturePDF.GetTextHeight(fontName, 20, True)
            status = gdpicturePDF.GetStat()
            If status = GdPictureStatus.OK Then
                message = message + "The height of the Times-Roman font with the size 20, with respect to the font boundary box, is " + height.ToString() + " centimeters."
            Else
                message = message + "The GetTextHeight() method has failed with the status: " + status.ToString()
            End If
            
            height = gdpicturePDF.GetTextHeight(fontName, 20, False)
            status = gdpicturePDF.GetStat()
            If status = GdPictureStatus.OK Then
                message = message + vbCrLf + "The height of the Times-Roman font with the size 20, without respecting the font boundary box, is " + height.ToString() + " centimeters."
            Else
                message = message + vbCrLf + "The GetTextHeight() method has failed with the status: " + status.ToString()
            End If
            MessageBox.Show(message, caption)
        Else
            MessageBox.Show("The AddStandardFont() method has failed with the status: " + status.ToString(), caption)
        End If
    Else
        MessageBox.Show("Units can't be set correctly.", caption)
    End If
Else
    MessageBox.Show("The file can't be loaded.", caption)
End If
gdpicturePDF.Dispose()

string caption = "Example: GetTextHeight";
GdPicturePDF gdpicturePDF = new GdPicturePDF();
GdPictureStatus status = gdpicturePDF.LoadFromFile("test.pdf", false);
if (status == GdPictureStatus.OK)
{
    gdpicturePDF.SetMeasurementUnit(PdfMeasurementUnit.PdfMeasurementUnitCentimeter);
    status = gdpicturePDF.GetStat();
    if (status == GdPictureStatus.OK)
    {
        string fontName = gdpicturePDF.AddStandardFont(PdfStandardFont.PdfStandardFontTimesRoman);
        if (gdpicturePDF.GetStat() == GdPictureStatus.OK)
        {
            string message = "";
            float height = gdpicturePDF.GetTextHeight(fontName, 20, true);
            status = gdpicturePDF.GetStat();
            if (status == GdPictureStatus.OK)
                message = message + "The height of the Times-Roman font with the size 20, with respect to the font boundary box, is " + height.ToString() + " centimeters.";
            else
                message = message + "The GetTextHeight() method has failed with the status: " + status.ToString();
            
            height = gdpicturePDF.GetTextHeight(fontName, 20, false);
            status = gdpicturePDF.GetStat();
            if (status == GdPictureStatus.OK)
                message = message + "\nThe height of the Times-Roman font with the size 20, without respecting the font boundary box, is " + height.ToString() + " centimeters.";
            else
                message = message + "\nThe GetTextHeight() method has failed with the status: " + status.ToString();
            MessageBox.Show(message, caption);
        }
        else
            MessageBox.Show("The AddStandardFont() method has failed with the status: " + status.ToString(), caption);
    }
    else
        MessageBox.Show("Units can't be set correctly.", caption);
}
else
    MessageBox.Show("The file can't be loaded.", caption);
gdpicturePDF.Dispose();

Reference

GdPicturePDF Class
GdPicturePDF Members
Overload List
GetTextWidth Method
DrawText Method
AddStandardFont Method
AddTrueTypeFont Method
SetMeasurementUnit Method
SetOrigin Method