convert papersource.sourcename to papersource.kind

Question

Hey I have 2 types of data in the namespace System.Drawing.Printing: Papersource.sourceName and Papersource.Kind. SourceName gets the name og the papertrays from a printer like tray 1 Kind gets the int value from the printer so fx. tray 1 have a kind value of 258. in my combobox i only want to show the sourcenames but if i choose tray 1 i want to get a messagebox where i get the kind value of the sourcename. Does anyone understand and have a example :)

Vulpes · Answer

Try it like this: PrinterSettings ps = new PrinterSettings(); PrinterData pd = new PrinterData(); PrintDocument printDoc = new PrintDocument(); PaperSource pkSource; ArrayList arr = new ArrayList(); private void Form1_Load(object sender EventArgs) { for (int i = 0; i { if (printDoc.PrinterSettings.PaperSources[i].SourceName == Frontoffice) { pkSource = printDoc.PrinterSettings.PaperSources[i]; } arr.Add(printDoc.PrinterSettings.PaperSources[i]); } comboPaperSource.DataSource = arr; comboPaperSource.DisplayMember = SourceName; comboPaperSource.ValueMember = RawKind; comboPaperSource.SelectedItem = pkSource; }

Vulpes · Answer

Well you will only need to load the DropDownList once and so all the code in Page_Load should be subject to it not being a postback: if (!IsPostBack) { // code } I'd declare the three fields to be protected rather than private (the default). Also this line: DropDownList1.SelectedValue = pkSource.ToString(); should be: DropDownList1.SelectedValue = pkSource.RawKind.ToString(); However if pkSource is null (which would explain the exception) then that suggests that there isn't a paper source on the server printer with a SourceName property of 'test'. It's certainly possible to create a Dictionary (say) to map the RawKind numbers to the SourceName but I don't really see the point of doing this when databinding the DropDownList to a List of PaperSource objects should achieve the same effect.

jesper · Answer

public partial class _Default : System . Web . UI . Page { PrintDocument printDoc = new PrintDocument (); PaperSource pkSource ; List listPaperSource = new List (); protected void Page_Load ( object sender  EventArgs e ) { for ( int i = 0 ; i printDoc . PrinterSettings . PaperSources . Count ; i ++) { if ( printDoc . PrinterSettings . PaperSources [ i ]. SourceName == test ) { pkSource = printDoc . PrinterSettings . PaperSources [ i ]; } listPaperSource . Add ( printDoc . PrinterSettings . PaperSources [ i ]); } DropDownList1 . DataSource = listPaperSource ; DropDownList1 . DataTextField = SourceName ; DropDownList1 . DataValueField = RawKind ; DropDownList1 . SelectedValue = pkSource . ToString (); DropDownList1 . DataBind (); } if i use selectedvalue instead i get no errors only when i compile it says: {Object reference not set to an instance of an object.} does it help you ? :) is it because of a postback ? can i in someway use a 2 dimensional list to hold sourcename and rawkind value ? and in that way get the rawkind that is corrosponding to the sourcename?

Vulpes · Answer

Sorry in my previous post I should have set the SelectedValue to the RawKind property of the paper source: comboPaperSource.SelectedValue = pkSource.RawKind.ToString(); That should cause the corresponding SourceName to be displayed in the DropDownList.

jesper · Answer

can i do somthing like saving the selectedvalue into a list or arraylist so i can get the rawkind number in this way ? i dont need to display the rawkind to the user but only the sourcename.. the rawkind number is only to change the papersource

Vulpes · Answer

TBH web applications are not really my thing but you will have problems with this line: comboPaperSource.SelectedItem = pkSource; because the SelectedItem property of the DropDownList (the equivalent of the ComboBox in ASP.NET) is read-only. You'd need to replace it with a line such as this: comboPaperSource.SelectedValue = pkSource.SourceName; However notice that this code will only show the papersources in relation to a printer attached to the server - not the client which can't be accessed directly for security reasons. To do the same for the client you'd either need to use javascript or to ask the client to install a custom windows control (impossible of course unless the client machine is running Windows).

jesper · Answer

do you know how to do this in a webform ? cus i cant figure it out /: the code attached is the same as the accepted question in here :) or maybe have an alternative solution :i

jesper · Answer

Thanks mate.. it works perfectly :)

jesper · Answer

This i my example PrinterSettings ps = new PrinterSettings(); PrinterData pd = new PrinterData(); PrintDocument printDoc = new PrintDocument(); PaperSource pkSource; ArrayList arr = new ArrayList(); private void Form1_Load(object sender EventArgs e) { comboPaperSource.DisplayMember = Frontoffice; for (int i = 0; i { pkSource = printDoc.PrinterSettings.PaperSources[i]; } arr.Add(pkSource); comboPaperSource.DisplayMember = pkSource.SourceName; comboPaperSource.ValueMember = pkSource.RawKind.ToString(); } But is dosent work. you can see i use 2 displaynames because the first is where i declare which printer i wanna have information from. and secondly there is no data in my combobox.

Vulpes · Answer

If you set the combobox's: 1 DataSource property to an array or List of PaperSource objects 2. DisplayMember property to SourceName; and 3. ValueMember property to Kind or RawKind then when the selection changes you can just show the current SelectedValue in the MessageBox: MessageBox.Show(comboBox1.SelectedValue.ToString());