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Getting an NSTableView to display something

The problem with an NSTableView is that we cannot tell it what to do. NSTableView works like the old joke about Soviet Russia: "In Soviet Russia television watches you". In other words, instead of us calling methods in the NSTableView object, the NSTableView object expects us to provide a data source object with methods for the NSTableView object to call.

Our plan shall be to put an NSTableView in our window and then write a class that acts as its data source, instantiate the class and hope for the best.

1. Double-click MainWindow.xib to open Xcode.

2. In Xcode, find the main window. It's the big thing that looks like a window.

3. In the Object Library find an NSTableView control.

Picture 1: We found an NSTableView in the Object Library

4. Drag the NSTableView into the window.

Picture 2: The window with an NSTableView

Note that the NSTableView is embedded in an NSScrollView which we will try to ignore.

5. Try clicking on the actual NSTableView control.

Picture 3: We managed to click on the actual NSTableView control.

6. Find the configuration thingy for the NSTableView control and configure it for one column, with no reordering or resizing.

Picture 4: The NSTableView configuration thingy.

7. Find the button to call the Assistant editor.

Picture 5: Found the Assistant editor button.

8. Configure the Assistant editor to display MainWindow.h and control-drag the NSTableView control into the MainWindow class.

Picture 6: Name the outlet "tblTable".

9. Add a file TableViewDataSource.cs with the following content.

// File TableViewDataSource.cs
using System;
using System.Collections.Generic;
using System.Linq;
using MonoMac.Foundation;
using MonoMac.AppKit;

namespace Test
    [Register ("TableViewDataSource")]
    public class TableViewDataSource : NSTableViewDataSource
        public TableViewDataSource ()
        // This method will be called by the NSTableView control to learn the number of rows to display.
        [Export ("numberOfRowsInTableView:")]
        public int NumberOfRowsInTableView(NSTableView table)
            // We just return a static 2. We will have two rows.
            return 2;
        // This method will be called by the control for each column and each row.
        [Export ("tableView:objectValueForTableColumn:row:")]
        public NSObject ObjectValueForTableColumn(NSTableView table, NSTableColumn col, int row)
            switch (row)
            case 0:
                // We will write "Hello" in the first row...
                return new NSString("Hello");
            case 1:
                // ...and "World" in the second.
                return new NSString("World");
                // Note that NSTableView requires an NSString, which we create with new NSString("bla").
                // We need a default value.
                return null;

10. Modify MainWindow.cs to include the following.

    // This method will be called automatically when the main window "wakes up".
    [Export ("awakeFromNib:")]
    public override void AwakeFromNib()
        tblTable.DataSource = new TableViewDataSource();
MainWindow.cs knows about tblTable. All we have to do to connect our NSTableView control to our data source is to tell tblTable that its data source is a new instance of TableViewDataSource.

11. Run the application and see that "Hello" and "World" are being displayed in the NSTableView.

Picture 7: Result!
(c) Andrew J. Brehm
Feel free to copy/translate/whatever but keep a pointer to the original location in case I find one of my many, many mistakes and update the document.
Zurich, January 23rd 2012