GdPicture.NET.14
GdPicture14 Namespace / GdPicturePDF Class / GetAnnotationOpacity Method
The 0-based index of the required annotation within the current page. It must be a value from 0 to GetAnnotationCount-1.
Example





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GetAnnotationOpacity Method (GdPicturePDF)
In This Topic
Returns 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
'Declaration
 
Public Function GetAnnotationOpacity( _
   ByVal AnnotationIdx As Integer _
) As Byte
public byte GetAnnotationOpacity( 
   int AnnotationIdx
)
public function GetAnnotationOpacity( 
    AnnotationIdx: Integer
): Byte; 
public function GetAnnotationOpacity( 
   AnnotationIdx : int
) : byte;
public: byte GetAnnotationOpacity( 
   int AnnotationIdx
) 
public:
byte GetAnnotationOpacity( 
   int AnnotationIdx
) 

Parameters

AnnotationIdx
The 0-based index of the required annotation within the current page. It must be a value from 0 to GetAnnotationCount-1.

Return Value

The opacity value from 0 (full transparency) to 255 (full opacity) of the specified annotation object. 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.

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

Example
How to retrieve the opacity and some other properties of all stamp annotation objects within the PDF document.
Dim caption As String = "Example: GetAnnotationOpacity"
Dim gdpicturePDF As GdPicturePDF = New GdPicturePDF()
Dim status As GdPictureStatus = gdpicturePDF.LoadFromFile("test.pdf", False)
If status = GdPictureStatus.OK Then
    Dim message As String = ""
    Dim pageCount As Integer = gdpicturePDF.GetPageCount()
    For i As Integer = 1 To pageCount
        status = gdpicturePDF.SelectPage(i)
        If status = GdPictureStatus.OK Then
            message = message + "The page nr." + i.ToString()
            Dim annotCount As Integer = gdpicturePDF.GetAnnotationCount()
            status = gdpicturePDF.GetStat()
            If status = GdPictureStatus.OK Then
                If annotCount = 0 Then
                    message = message + " does not contain any annotations."
                Else
                    Dim annotSubType As String = ""
                    Dim color As Color = Color.Black, fillColor As Color = Color.Black
                    Dim opacity As Byte = 0
                    Dim l As Single = 0, t As Single = 0, w As Single = 0, h As Single = 0
                    For j As Integer = 0 To annotCount - 1
                        annotSubType = gdpicturePDF.GetAnnotationSubType(j)
                        If gdpicturePDF.GetStat() = GdPictureStatus.OK Then
                            If annotSubType.Equals("Stamp") Then
                                message = message + vbCrLf + "AnnotID: " + j.ToString()
                                message = message + vbCrLf + "    color: "
                                color = gdpicturePDF.GetAnnotationColor(j)
                                status = gdpicturePDF.GetStat()
                                If status = GdPictureStatus.OK Then message = message + color.ToString() Else message = message + status.ToString()
                                message = message + "    fill color: "
                                fillColor = gdpicturePDF.GetAnnotationFillColor(j)
                                status = gdpicturePDF.GetStat()
                                If status = GdPictureStatus.OK Then message = message + fillColor.ToString() Else message = message + status.ToString()
                                message = message + "    opacity: "
                                opacity = gdpicturePDF.GetAnnotationOpacity(j)
                                status = gdpicturePDF.GetStat()
                                If status = GdPictureStatus.OK Then message = message + opacity.ToString() Else message = message + status.ToString()
                                message = message + "    rectangle: "
                                status = gdpicturePDF.GetAnnotationRect(j, l, t, w, h)
                                If status = GdPictureStatus.OK Then message = message + "[" + l.ToString() + "," + t.ToString() + " ; w:" + w.ToString() + " h:" + h.ToString() + "]" Else message = message + status.ToString()
                            End If
                        Else
                            message = message + vbCrLf + "The GetAnnotationSubType() method has failed with the status: " + status.ToString()
                        End If
                    Next
                End If
            Else
                message = message + ": the GetAnnotationCount() method has failed with the status: " + status.ToString()
            End If
            message = message + vbCrLf
        Else
            message = message + "The SelectPage(" + i.ToString() + ") method has failed with the status: " + status.ToString() + vbCrLf
        End If
    Next
    MessageBox.Show(message, caption)
Else
    MessageBox.Show("The file can't be loaded.", caption)
End If
gdpicturePDF.Dispose()
string caption = "Example: GetAnnotationOpacity";
GdPicturePDF gdpicturePDF = new GdPicturePDF();
GdPictureStatus status = gdpicturePDF.LoadFromFile("test.pdf", false);
if (status == GdPictureStatus.OK)
{
    string message = "";
    int pageCount = gdpicturePDF.GetPageCount();
    for (int i = 1; i <= pageCount; i++)
    {
        status = gdpicturePDF.SelectPage(i);
        if (status == GdPictureStatus.OK)
        {
            message = message + "The page nr." + i.ToString();
            int annotCount = gdpicturePDF.GetAnnotationCount();
            status = gdpicturePDF.GetStat();
            if (status == GdPictureStatus.OK)
            {
                if (annotCount == 0)
                {
                    message = message + " does not contain any annotations.";
                }
                else
                {
                    string annotSubType = "";
                    Color color = Color.Black, fillColor = Color.Black;
                    byte opacity = 0;
                    float l = 0, t = 0, w = 0, h = 0;
                    for (int j = 0; j < annotCount; j++)
                    {
                        annotSubType = gdpicturePDF.GetAnnotationSubType(j);
                        if (gdpicturePDF.GetStat() == GdPictureStatus.OK)
                        {
                            if (annotSubType.Equals("Stamp"))
                            {
                                message = message + "\nAnnotID: " + j.ToString();
            
                                message = message + "\n    color: ";
                                color = gdpicturePDF.GetAnnotationColor(j);
                                status = gdpicturePDF.GetStat();
                                if (status == GdPictureStatus.OK) message = message + color;
                                else message = message + status.ToString();
            
                                message = message + "    fill color: ";
                                fillColor = gdpicturePDF.GetAnnotationFillColor(j);
                                status = gdpicturePDF.GetStat();
                                if (status == GdPictureStatus.OK) message = message + fillColor;
                                else message = message + status.ToString();
            
                                message = message + "    opacity: ";
                                opacity = gdpicturePDF.GetAnnotationOpacity(j);
                                status = gdpicturePDF.GetStat();
                                if (status == GdPictureStatus.OK) message = message + opacity.ToString();
                                else message = message + status.ToString();
            
                                message = message + "    rectangle: ";
                                status = gdpicturePDF.GetAnnotationRect(j, ref l, ref t, ref w, ref h);
                                if (status == GdPictureStatus.OK) message = message + "[" + l.ToString() + "," + t.ToString() + " ; w:" + w.ToString() + " h:" + h.ToString() + "]";
                                else message = message + status.ToString();
                            }
                        }
                        else
                        {
                            message = message + "\nThe GetAnnotationSubType() method has failed with the status: " + status.ToString();
                        }
                    }
                }
            }
            else
                message = message + ": the GetAnnotationCount() method has failed with the status: " + status.ToString();
            
            message = message + "\n";
        }
        else
            message = message + "The SelectPage(" + i.ToString() + ") method has failed with the status: " + status.ToString() + "\n";
    }
    MessageBox.Show(message, caption);
}
else
{
    MessageBox.Show("The file can't be loaded.", caption);
}
gdpicturePDF.Dispose();
See Also