GdPicture.NET Reference Guide
GetRegionTopPixels Method (GdViewer)
Example 





GdPicture14.WPF Namespace > GdViewer Class : GetRegionTopPixels Method
A unique region identifier of the specified region. You can obtain this identifier using the GetRegionID method or when creating regions using the AddRegion(String,Double,Double,Double,Double,Color,RegionFillMode) method.
Gets the vertical (Y) coordinate of the top left point, in pixels, where the highlighted region's rectangle is located on the actual document (meaning the document pages area). The highlighted region is specified by its unique identifier related to the document currently displayed in the GdViewer control. These regions, if present, determines the currently defined highlighted regions on the displayed document.

You can define this coordinate of the region's rectangle when adding regions using the AddRegion(String,Double,Double,Double,Double,Color,RegionFillMode) method or directly using the SetRegionTop method.

Syntax
'Declaration
 
Public Function GetRegionTopPixels( _
   ByVal RegionID As Integer _
) As Double
public double GetRegionTopPixels( 
   int RegionID
)
public function GetRegionTopPixels( 
    RegionID: Integer
): Double; 
public function GetRegionTopPixels( 
   RegionID : int
) : double;
public: double GetRegionTopPixels( 
   int RegionID
) 
public:
double GetRegionTopPixels( 
   int RegionID
) 

Parameters

RegionID
A unique region identifier of the specified region. You can obtain this identifier using the GetRegionID method or when creating regions using the AddRegion(String,Double,Double,Double,Double,Color,RegionFillMode) method.

Return Value

The vertical coordinate of the top left point, in pixels, of the highlighted region's rectangle, related to the actual document. Please always use the GetStat method to determine if this method has been successful.
Remarks
Be aware that if the required region does not exist, the method will fail.

Please note that the returned value corresponds to the actual document area, it is not related to the GdViewer control area.

Example
How to draw a rectangle on the document's page according to the user's selection of the highlighted rectangle in the GdViewer control.
'We assume that the GdViewer1 control has been properly integrated
'and some PDF document is loaded and displayed as well.
 
'Here we make use of the RegionSelected event.
Sub GdViewer1_RegionSelected(ByVal sender As Object, ByVal e As GdPicture14.WPF.GdViewer.RegionSelectedEventArgs)
    Dim page As Integer = GdViewer1.GetRegionPage(e.RegionID)
    'Converting pixels to PDF points.
    Dim left As Integer = GdViewer1.GetRegionLeftPixels(e.RegionID) * 0.75
    Dim top As Integer = GdViewer1.GetRegionTopPixels(e.RegionID) * 0.75
    Dim width As Integer = GdViewer1.GetRegionWidthPixels(e.RegionID) * 0.75
    Dim height As Integer = GdViewer1.GetRegionHeightPixels(e.RegionID) * 0.75
    Using oPDF As GdPicturePDF = New GdPicturePDF()
        If oPDF.LoadFromFile(GdViewer1.GetLastPath(), False) = GdPictureStatus.OK Then
            oPDF.SetMeasurementUnit(PdfMeasurementUnit.PdfMeasurementUnitPoint)
            oPDF.SetOrigin(PdfOrigin.PdfOriginTopLeft)
            'Drawing a rectangle on the document's page according to the selected rectangle in the GdViewer1 control.
            If (oPDF.SelectPage(page) = GdPictureStatus.OK) AndAlso
               (oPDF.SetFillAlpha(150) = GdPictureStatus.OK) AndAlso
               (oPDF.SetFillColor(0, 191, 255) = GdPictureStatus.OK) AndAlso
               (oPDF.DrawRectangle(left, top, width, height, True, False) = GdPictureStatus.OK) Then
                If oPDF.SaveToFile("test_region.pdf") = GdPictureStatus.OK Then
                    MessageBox.Show("The file has been saved successfully.", "GdViewer.GetRegionTopPixels")
                Else
                    MessageBox.Show("The file can't be saved. Status: " + oPDF.GetStat().ToString(), "GdViewer.GetRegionTopPixels")
                End If
            Else
                MessageBox.Show("The graphics operations have failed. Status: " + oPDF.GetStat().ToString(), "GdViewer.GetRegionTopPixels")
            End If
        Else
            MessageBox.Show("The file can't be loaded. Status: " + oPDF.GetStat().ToString(), "GdViewer.GetRegionTopPixels")
        End If
    End Using
End Sub
//We assume that the GdViewer1 control has been properly integrated.
//and some PDF document is loaded and displayed as well.
 
//Here we make use of the RegionSelected event.
void GdViewer1_RegionSelected(object sender, GdPicture14.WPF.GdViewer.RegionSelectedEventArgs e)
{
    int page = GdViewer1.GetRegionPage(e.RegionID);
    //Converting pixels to PDF points.
    int left = (int)(GdViewer1.GetRegionLeftPixels(e.RegionID) * 0.75);
    int top = (int)(GdViewer1.GetRegionTopPixels(e.RegionID) * 0.75);
    int width = (int)(GdViewer1.GetRegionWidthPixels(e.RegionID) * 0.75);
    int height = (int)(GdViewer1.GetRegionHeightPixels(e.RegionID) * 0.75);
    using (GdPicturePDF oPDF = new GdPicturePDF())
    {
        if (oPDF.LoadFromFile(GdViewer1.GetLastPath(), false) == GdPictureStatus.OK)
        {
            oPDF.SetMeasurementUnit(PdfMeasurementUnit.PdfMeasurementUnitPoint);
            oPDF.SetOrigin(PdfOrigin.PdfOriginTopLeft);
            //Drawing a rectangle on the document's page according to the selected rectangle in the GdViewer1 control.
            if ((oPDF.SelectPage(page) == GdPictureStatus.OK) &&
                (oPDF.SetFillAlpha(150) == GdPictureStatus.OK) &&
                (oPDF.SetFillColor(0, 191, 255) == GdPictureStatus.OK) &&
                (oPDF.DrawRectangle(left, top, width, height, true, false) == GdPictureStatus.OK))
            {
                if (oPDF.SaveToFile("test_region.pdf") == GdPictureStatus.OK)
                    MessageBox.Show("The file has been saved successfully.", "GdViewer.GetRegionTopPixels");
                else
                    MessageBox.Show("The file can't be saved. Status: " + oPDF.GetStat().ToString(), "GdViewer.GetRegionTopPixels");
            }
            else
                MessageBox.Show("The graphics operations have failed. Status: " + oPDF.GetStat().ToString(), "GdViewer.GetRegionTopPixels");
        }
        else
            MessageBox.Show("The file can't be loaded. Status: " + oPDF.GetStat().ToString(), "GdViewer.GetRegionTopPixels");
    }
}
See Also

Reference

GdViewer Class
GdViewer Members
RegionSelected Event
RegionCount Method
GetRegionID Method
SearchText(String,Int32,Boolean) Method
SearchText(String,Int32,Boolean,Boolean) Method
AddRegion(String,Double,Double,Double,Double,Color,RegionFillMode) Method
GetRegionTop Method
SetRegionTop Method