GdPicture.NET.14
GdPicture14 Namespace / GdViewer Class / GetRectTopOnViewer Method
Example





GetRectTopOnViewer Method (GdViewer)
Returns the vertical (Y) coordinate (0-based) of the top left point, in pixels, of the rectangle of area selection, related to the document displayed in the GdViewer control. The resulting coordinate corresponds to the viewer area. You can determine, if the rectangle of selection is currently defined and drawn within the control, using the GdViewer.IsRect method.
Syntax
'Declaration
 
Public Function GetRectTopOnViewer() As Integer
 

Return Value

The vertical coordinate of the top left point, in pixels, of the rectangle of selection, related to the viewer area.
Remarks
Be aware that you are allowed to define only one rectangle of selection within the GdViewer control. Likewise, this rectangle always relates to the currently displayed document, meaning that without displaying some document you cannot get valid rectangle's data.

Just to remind you, that this coordinate is 0-based with the origin being in the top left corner in the viewer area.

Example
How to compare the coordinates of the rectangle of selection related to the document pages area with those related to the viewer area.
'We assume that the GdViewer1 control has been properly integrated.
If GdViewer1.DisplayFromFile("") = GdPictureStatus.OK Then
    Dim text_to_find As String = "GdPicture"
    GdViewer1.ClearRect()
    Dim text_found As Boolean = GdViewer1.SearchText(text_to_find, 1, True)
    If GdViewer1.GetStat() = GdPictureStatus.OK Then
        If text_found AndAlso GdViewer1.IsRect() Then
            GdViewer1.CenterOnRect()
            'Finding coordinates to compare.
            Dim leftViewer As Integer = GdViewer1.GetRectLeftOnViewer()
            Dim leftDoc As Integer = GdViewer1.GetRectLeftOnDocument()
            Dim topViewer As Integer = GdViewer1.GetRectTopOnViewer()
            Dim topDoc As Integer = GdViewer1.GetRectTopOnDocument()
            MessageBox.Show("The location point on the viewer is " + leftViewer + ", " + topViewer + "." + vbLf +
                            "The location point on the document's page is " + leftDoc + ", " + topDoc + ".", "GdViewer.GetRectTopOnViewer")
        Else
            MessageBox.Show("The given text has not been found.", "GdViewer.GetRectTopOnViewer")
        End If
    Else
        MessageBox.Show("The search process has failed. Status: " + GdViewer1.GetStat().ToString(), "GdViewer.GetRectTopOnViewer")
    End If
Else
    MessageBox.Show("The file can't be displayed. Status: " + GdViewer1.GetStat().ToString(), "GdViewer.GetRectTopOnViewer")
End If
See Also