SetAnnotationOpacity Method (GdPicturePDF)

In This Topic

Sets the opacity value of a required annotation object specified by its index related to the currently selected page of the loaded PDF document. This value is used when painting the annotation and it applies to all visible elements of the annotation in its closed state except of the pop-up window.

Syntax

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

'Declaration
 
Public Function SetAnnotationOpacity( _
   ByVal AnnotationIdx As Integer, _
   ByVal Opacity As Byte _
) As GdPictureStatus

public GdPictureStatus SetAnnotationOpacity( 
   int AnnotationIdx,
   byte Opacity
)

public function SetAnnotationOpacity( 
    AnnotationIdx: Integer;
    Opacity: Byte
): GdPictureStatus;

public function SetAnnotationOpacity( 
   AnnotationIdx : int,
   Opacity : byte
) : GdPictureStatus;

public: GdPictureStatus SetAnnotationOpacity( 
   int AnnotationIdx,
   byte Opacity
)

public:
GdPictureStatus SetAnnotationOpacity( 
   int AnnotationIdx,
   byte Opacity
)

Parameters

AnnotationIdx: The 0-based index of the required annotation within the current page. It must be a value from 0 to GetAnnotationCount-1.
Opacity: The new opacity value from 0 (full transparency) to 255 (full opacity) of the specified annotation object.

Return Value

A member of the GdPictureStatus enumeration. If the method has been successfully followed, then the return value is GdPictureStatus.OK.

We strongly recommend always checking this status first.

Remarks

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

Likewise always ensure that you have selected the correct page using the SelectPage method before applying an annotation index.

Example

How to change the opacity of all annotations in the loaded PDF document.

VB.NET
C#

Dim caption As String = "Example: SetAnnotationOpacity"
Dim gdpicturePDF As GdPicturePDF = New GdPicturePDF()
If gdpicturePDF.LoadFromFile("test.pdf", False) = GdPictureStatus.OK Then
    Dim pageCount As Integer = gdpicturePDF.GetPageCount()
    If gdpicturePDF.GetStat() = GdPictureStatus.OK Then
        Dim message As String = ""
        Dim status As GdPictureStatus = GdPictureStatus.OK
        For page As Integer = 1 To pageCount
            message = message + "Page nr." + page.ToString()
            status = gdpicturePDF.SelectPage(page)
            If status = GdPictureStatus.OK Then
                Dim annotCount As Integer = gdpicturePDF.GetAnnotationCount()
                status = gdpicturePDF.GetStat()
                If status = GdPictureStatus.OK Then
                    message = message + "  Annots: " + annotCount.ToString()
                    For annotID As Integer = 0 To annotCount - 1
                        status = gdpicturePDF.SetAnnotationOpacity(annotID, 128)
                        If status <> GdPictureStatus.OK Then Exit For
                    Next
                    message = message + "  status: " + status.ToString()
                Else
                    message = message + "GetAnnotationCount - status: " + status.ToString()
                End If
            Else
                message = message + "SelectPage - status: " + status.ToString()
            End If
            message += vbCrLf
        Next
        If gdpicturePDF.SaveToFile("test_opacity.pdf") = GdPictureStatus.OK Then
            message = message + "The file has been saved."
        Else
            message = message + "The file can't be saved. Status: " + gdpicturePDF.GetStat().ToString()
        End If
        MessageBox.Show(message, caption)
    Else
        MessageBox.Show("The GetPageCount() method has failed with the status: " + gdpicturePDF.GetStat().ToString(), caption)
    End If
Else
    MessageBox.Show("The file can't be loaded.", caption)
End If
gdpicturePDF.Dispose()

string caption = "Example: SetAnnotationOpacity";
GdPicturePDF gdpicturePDF = new GdPicturePDF();
if (gdpicturePDF.LoadFromFile("test.pdf", false) == GdPictureStatus.OK)
{
    int pageCount = gdpicturePDF.GetPageCount();
    if (gdpicturePDF.GetStat() == GdPictureStatus.OK)
    {
        string message = "";
        GdPictureStatus status = GdPictureStatus.OK;
        for (int page = 1; page <= pageCount; page++)
        {
            message = message + "Page nr." + page.ToString();
            status = gdpicturePDF.SelectPage(page);
            if (status == GdPictureStatus.OK)
            {
                int annotCount = gdpicturePDF.GetAnnotationCount();
                status = gdpicturePDF.GetStat();
                if (status == GdPictureStatus.OK)
                {
                    message = message + "  Annots: " + annotCount.ToString();
                    for (int annotID = 0; annotID < annotCount; annotID++)
                    {
                        status = gdpicturePDF.SetAnnotationOpacity(annotID, 128);
                        if (status != GdPictureStatus.OK) break;
                    }
                    message = message + "  status: " + status.ToString();
                }
                else
                    message = message + "GetAnnotationCount - status: " + status.ToString();
            }
            else
                message = message + "SelectPage - status: " + status.ToString();
            message += "\n";
        }
        if (gdpicturePDF.SaveToFile("test_opacity.pdf") == GdPictureStatus.OK)
            message = message + "The file has been saved.";
        else
            message = message + "The file can't be saved. Status: " + gdpicturePDF.GetStat().ToString();
        MessageBox.Show(message, caption);
    }
    else
        MessageBox.Show("The GetPageCount() method has failed with the status: " + gdpicturePDF.GetStat().ToString(), caption);
}
else
    MessageBox.Show("The file can't be loaded.", caption);
gdpicturePDF.Dispose();

Reference

GdPicturePDF Class
GdPicturePDF Members
GetAnnotationCount Method
GetAnnotationSubType Method
GetAnnotationOpacity Method