GetRegionLeftPixels Method (GdViewer)

In This Topic

Gets the horizontal (X) 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'rectangle when adding regions using AddRegion(String,Int32,Int32,Int32,Int32,ForegroundMixMode,Int32) or AddRegionInches(String,Single,Single,Single,Single,ForegroundMixMode,Int32) methods or directly using the SetRegionLeftPixels method.

Syntax

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

'Declaration
 
Public Function GetRegionLeftPixels( _
   ByVal RegionID As Integer _
) As Integer

public int GetRegionLeftPixels( 
   int RegionID
)

public function GetRegionLeftPixels( 
    RegionID: Integer
): Integer;

public function GetRegionLeftPixels( 
   RegionID : int
) : int;

public: int GetRegionLeftPixels( 
   int RegionID
)

public:
int GetRegionLeftPixels( 
   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 AddRegion(String,Int32,Int32,Int32,Int32,ForegroundMixMode,Int32) or AddRegionInches(String,Single,Single,Single,Single,ForegroundMixMode,Int32) methods.

Return Value

The horizontal coordinate of the top left point, in pixels, of the highlighted region's rectangle, related to the actual document. The GetStat method can be subsequently used 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.

VB.NET
C#

'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 RegionSelectedByUser event.
Sub GdViewer1_RegionSelectedByUser(ByVal RegionID As Integer)
    Dim page As Integer = GdViewer1.GetRegionPage(RegionID)
    'Converting pixels to PDF points.
    Dim left As Integer = GdViewer1.GetRegionLeftPixels(RegionID) * 0.75
    Dim top As Integer = GdViewer1.GetRegionTopPixels(RegionID) * 0.75
    Dim width As Integer = GdViewer1.GetRegionWidthPixels(RegionID) * 0.75
    Dim height As Integer = GdViewer1.GetRegionHeightPixels(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.GetRegionLeftPixels")
                Else
                    MessageBox.Show("The file can't be saved. Status: " + oPDF.GetStat().ToString(), "GdViewer.GetRegionLeftPixels")
                End If
            Else
                MessageBox.Show("The graphics operations have failed. Status: " + oPDF.GetStat().ToString(), "GdViewer.GetRegionLeftPixels")
            End If
        Else
            MessageBox.Show("The file can't be loaded. Status: " + oPDF.GetStat().ToString(), "GdViewer.GetRegionLeftPixels")
        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 RegionSelectedByUser event.
void GdViewer1_RegionSelectedByUser(int RegionID)
{
    int page = GdViewer1.GetRegionPage(RegionID);
    //Converting pixels to PDF points.
    int left = (int)(GdViewer1.GetRegionLeftPixels(RegionID) * 0.75);
    int top = (int)(GdViewer1.GetRegionTopPixels(RegionID) * 0.75);
    int width = (int)(GdViewer1.GetRegionWidthPixels(RegionID) * 0.75);
    int height = (int)(GdViewer1.GetRegionHeightPixels(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.GetRegionLeftPixels");
                else
                    MessageBox.Show("The file can't be saved. Status: " + oPDF.GetStat().ToString(), "GdViewer.GetRegionLeftPixels");
            }
            else
                MessageBox.Show("The graphics operations have failed. Status: " + oPDF.GetStat().ToString(), "GdViewer.GetRegionLeftPixels");
        }
        else
            MessageBox.Show("The file can't be loaded. Status: " + oPDF.GetStat().ToString(), "GdViewer.GetRegionLeftPixels");
    }
}

Reference

GdViewer Class
GdViewer Members
RegionSelectedByUser Event
SetRegionLeftPixels Method
RegionCount Method
GetRegionID Method
SearchText(String,Int32,Boolean) Method
AddRegion(String,Int32,Int32,Int32,Int32,ForegroundMixMode,Int32) Method
AddRegionInches(String,Single,Single,Single,Single,ForegroundMixMode,Int32) Method
GetRegionLeft Method
SetRegionLeft Method