PDFSharp - Using a variable instead of the color name?

[Rocky48]

I am trying to use PDFSharp to change the Font color dynamically, from a combo box.
The XBrushes class has the named colors as its property, however I want to use the combo box to allow the user to choose from the 141 colors available. I does not allow me to subsititute a variable instead of the color, at least the method I have tried, which may be incorrect.
This is the code for the line which gives me the error: 'TxtColorValue is not a member of XBrushes'

tf.DrawString(Ftext, CFont, XBrushes.TxtColorValue, rect, XStringFormats.TopLeft)

If this is impossible does anyone know how I can get the RGB values for all the colors that PDFSharp XBrushes lists?
Any help will be appreciated!

[jmcilhinney]

Of course it will let you use a variable, but you have to use a variable of the correct type, as is always the case. Why do you think the XBrushes type has a member with that name in the first place? You say that you're trying to use a value from a ComboBox but I don't see any reference to a ComboBox there. Presumably you need to populate that ComboBox with Color values (or whatever specific type that method expects) and then get the user's selection from the SelectedValue of the ComboBox.

[passel]

I guess you could look at the code for PDFSharp.
The values for the colors would be in XKnownColorTable.cs
Its the same colors that GDI+ uses, so you could probably use the ColorDialog to select the color and then create a brush and cast it to an XBrush.

I don't know for a fact though, since I haven't dealt with it.

[Rocky48]

I did not show the whole code as all I was asking is HOW you write a variable as the property of XBrushes, as it only accepts the name of the color property. i.e. Black
The color combo is bound into the combobox with the following set:
Display member: Color
Value Member: XID

The following code is run to select the color in the combo box:

 Private Sub cboColor_SelectedIndexChanged(sender As Object, e As EventArgs) Handles cboColor.SelectedIndexChanged
        Me.TxtColorTableAdapter.Fill(Me.ColorDataSet.TxtColor)
        Dim TxtColorValue As Integer
        Dim cboColor As Object = Nothing
        TxtColorValue = cboColor.selectedvalue
    End Sub

So the question I am asking is how do I represent the color for the XBrushes property instead of a color?

I have another problem at the moment in the Application Designer.vb which I will post separately.

[jmcilhinney]

I did not show the whole code as all I was asking is HOW you write a variable as the property of XBrushes

There is no answer to that question because it is nonsensical as asked. You need to think the whole problem through. Firstly, the DrawString method you are calling in post #1 has five parameters and the third parameter is the one of interest. What is the type of that parameter? What you are passing to it now is irrelevant. All that matters is the type. Once you know the type of the parameter, you know what type the value has to be that you pass as a parameter. If you expect that value to come from a ComboBox then obviously you need values of that type in the ComboBox in the first place and then you can get a value of that type from the ComboBox when the user makes a selection.

[passel]

The third parameter is an XBrush.
So you could create a combobox with a bunch of XBrush objects, set to the brush color you want.
As for a variable, you should just be able to declare a variable of that type as well.

I don't have PDFSharp, but an example like this might work.

Imports PdfSharp
Imports PdfSharp.Drawing
Imports PdfSharp.Pdf

Public Class Form1
    Private myBrushes() As XBrush = {XBrushes.Red, XBrushes.Green, XBrushes.Blue, XBrushes.Black, XBrushes.White, XBrushes.Yellow}

    Private SelectedBrushByColor As XBrush = XBrushes.AliceBlue

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ComboBox1.Items.AddRange(myBrushes)
        ComboBox1.DisplayMember = "Color"

    End Sub

    Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
        SelectedBrushByColor = ComboBox1.SelectedItem
    End Sub

Then you would use SelectedBrushByColor in your drawing call, e.g. DrawString, for the third parameter.

tf.DrawString(Ftext, CFont, SelectedBrushByColor, rect, XStringFormats.TopLeft)

The DisplayMember = "Color" should display the color property of the various brushes in the Combobox, so the list should be "Red", "Green", "Blue", etc...

As mentioned, I don't have PDFSharp so couldn't test the example code above.

[Rocky48]

Passel.
Thanks for that! I was hoping that I could use the 141 XBrushes colors, but as a last resort I may use the method you have suggested for a cut down version. On my web version I did use a color picker to give users infinate choice of colours. Don't know whether you can do that with VB?

[passel]

XBrushes is just a wrapper for the GDI+ Brushes class if you're using winforms, or whatever the class is that wpf uses for the same thing if you're writing a wpf application.
So, the colors that XBrushes supports should be the same colors by the same name that GDI+ supports.
If you want to create any user defined color, you should be able to do that in a similar manner as the SolidBrush class does, being that the various X.... classes wraps all that same functionality.
Example to create a custom shade of red

Dim redBrush As XBrush = new XSolidBrush(XColor.FromArgb(224, 0, 64))

[Rocky48]

Passel
I have just tried the code that you wrote in #6, but I get a cast error:

System.InvalidCastException: 'Unable to cast object of type 'System.String' to type 'PdfSharp.Drawing.XBrush'.'

It errored on this line:

        SelectedBrushByColor = CType(cboColor.SelectedItem, XBrush)

I know that is different, but it says 'Option strict on disallows implicit conversions from Object to XBrush' when I entered the code as you suggested.
Is there a way around this?

[Rocky48]

Found why I got the cast error.
I had added the colors using the combobox control as well as programmatically.
However, instead of the color being displayed it just says: 'PDFSharp.Drawing.XColor'
Any suggestions why as it seems to be correct?

[jmcilhinney]

Finstead of the color being displayed it just says: 'PDFSharp.Drawing.XColor'

If you mean that that's what you see in the ComboBox, that's because a ComboBox will simply call ToString on each item to get the text to display by default. The default behaviour of ToString is to return the name of the type and that's what you're seeing, so default behaviour all round. If what you actually want displayed is the value of some property of each item then you do that by setting the DisplayMember of the ComboBox to the name of that property. If there is no such property then you have to manufacture your own items that do have such a property.

[Inferrd]

It would be simpler if you continued to populate the ComboBox with the names of the colours as Strings (no need to set the DisplayMember in that case).

Then create the brush 'on the fly' from the name when you need to draw your pdf text in the Print method:

'   create the brush
Dim xClrName As String = CStr(cboColor.SelectedItem)
Dim xclr As XColor = XColor.FromName(xClrName)
Dim brush As XSolidBrush = New XSolidBrush(xclr)

'   Draw the text
tf.DrawString(Ftext, font, brush, bounds, XStringFormats.TopLeft)

Even simpler would be to fetch a collection of the XKnownColor enum values and bind that collection to the ComboBox when setting up the Form. That would mean you wouldn't have to worry about storing and retrieving the values from a database.

Private Sub PrintForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    'This line populates the font combo with the system installed fonts
    For Each oFont As FontFamily In FontFamily.Families
        cboFont.Items.Add(oFont.Name)
    Next
    cboFont.SelectedIndex = 0

    'fetch the XKnownColor values into cboColor
    Dim knownColours() As XKnownColor = XColorResourceManager.GetKnownColors(includeTransparent:=False)
    cboColor.DataSource = knownColours
    cboColor.SelectedIndex = 0

End Sub

and in your Print method you would have something like:

'''Private Sub printIt()

    '   create the brush
    Dim xClr As XColor = XColor.FromKnownColor(CType(cboColor.SelectedItem, XKnownColor))
    Dim brush As XSolidBrush = New XSolidBrush(xClr)

    '   Draw the text
    tf.DrawString(Ftext, font, brush, bounds, XStringFormats.TopLeft)

Having said that, do you know that PDFSharp itself provides a ColorComboBox Control class that looks like this:

It can be found in the PdfSharp-gdi.dll assembly under the PdfSharp.Forms namespace, and you can add it to your IDE Designer toolbox.

[Rocky48]

I now have a working code for printing using PDFSharp:

 Private Sub btnPrint_Click(sender As Object, e As EventArgs) Handles btnPrint.Click

        Using connection As New SqlConnection(connectionString), da As New SqlDataAdapter("SELECT CID, BoxX, Cellw, Cellh, ort, Narrative FROM CSize WHERE CID = @CID", connection), dt As New DataTable
                connection.Open()

            da.SelectCommand.Parameters.AddWithValue("@CID", CSizeValue)
                da.Fill(dt)
                If dt.Rows.Count > 0 Then
                    Dim row As DataRow = dt.Rows(0)
                    printIt(row)



            End If

        End Using


    End Sub
    Private Sub printIt(row As DataRow)
        Dim ID As Double = CDbl(row("CID"))
        Dim X As Double = CDbl(row("BoxX")) * 2.83465
        Dim W As Double = CDbl(row("Cellw")) * 2.83465
        Dim H As Double = CDbl(row("Cellh")) * 2.83465
        Dim O As String = CStr(row("ort"))
        Dim N As String = CStr(row("Narrative"))
        Dim Y As Double
        Dim NL As String = CStr(Chr(13) & Chr(10))
        Verse = txbVerse.Text
        Replace(Verse, NL, " VBCrLf ")
        Dim document As PdfDocument
        ' Create a new PDF document
        document = New PdfDocument()
        document.Info.Title = "Created with PDFsharp"

        ' Create an empty page
        Dim page As PdfPage = document.AddPage

        If O = "L" Then
            page.Orientation = CType(pageOrientation.Landscape, PdfSharp.PageOrientation)
            page.Width = XUnit.FromMillimeter(297)
            page.Height = XUnit.FromMillimeter(210)
        Else
            page.Orientation = CType(pageOrientation.Portrait, PdfSharp.PageOrientation)
            page.Width = XUnit.FromMillimeter(210)
            page.Height = XUnit.FromMillimeter(297)
        End If

        '   create the brush
        Dim xClr As XColor = XColor.FromKnownColor(CType(cboColor.SelectedItem, XKnownColor))
        Dim brush As XSolidBrush = New XSolidBrush(xClr)

        ' Draw the text
        Y = boxY * 2.834665

        Dim gfx As XGraphics
        gfx = XGraphics.FromPdfPage(page)
        Dim tf As XTextFormatter
        tf = New XTextFormatter(gfx)
        Dim font As XFont = New XFont(CFont, FSize, XFontStyle.Regular)
        Dim rect As XRect
        rect = New XRect(X, Y, W, H)
        gfx.DrawRectangle(XBrushes.SeaShell, rect)
        tf.Alignment = XParagraphAlignment.Center
        tf.DrawString(Verse, font, brush, rect, XStringFormat.TopLeft)

        ' Save the document
        Dim filename As String = "verse.pdf"
        document.Save(filename)

        ' ...and start a viewer.
        Process.Start(filename)

    End Sub

Thanks for everyones help!