Reference of prototype cells from IB

问题:

I am doing iOS project with storyboards in MonoTouch.

I have the custom class of UITableView (myCustomTableFoo) and specified the prototype cells of this class in IB. Then I want to instance this class programmatically. The bad thing it's lacking the prototype cells, and I don't know how to insert that prototype cells to my programmatically created table object.

I have a storyboard and I want to use my prototype cells from IB in all my inherited table classes. I think MonoTouch could be pretty similar to Objective-c in this case.

回答1:

You could use

this._tableView.RegisterClassForCellReuse(typeof(MyCell), new NSString("MyReuseIdentifier"));

then you can dequeue your cell using

this._tableView.DequeueReusableCell("MyReuseIdentifier");

the cell would be automatically instantiated. You do need to register your class using [Register("MyCell") and it should have a constructor like

public MyCell(IntPtr handle) : base(handle) {

}

One thing though, I don't think you can reuse the cell you defined in your storyboard. If you want to reuse the same cells in different TableView instance, you can create a unique Nib for your cell and then something like that would do the trick:

public partial class MyCell : UITableViewCell {

    private MySuperCellView _mySuperNibView;

    public MyCell (IntPtr handle) : base (handle) {

    }

    private void checkState() {
        // Check if this is the first time the cell is instantiated
        if (this._mySuperNibView == null) {
            // It is, so create its view
            NSArray array = NSBundle.MainBundle.LoadNib("NibFileName", this, null);
            this._mySuperNibView = (MySuperCellView)Runtime.GetNSObject(array.ValueAt(0));
            this._mySuperNibView.Frame = this.Bounds;
            this._mySuperNibView.LayoutSubviews();

            this.AddSubview(this._mySuperNibView);
        }
    }

    public object cellData {
        get { return this._mySuperNibView.cellData; }
        set {
            this.checkState();
            this._mySuperNibView.cellData = value;
        }
    }
}

Here I'm using a generic view defined on an external Nib. I manually instantiate it when feeding the data into the Cell if it doesn't has been yet instantiated. It happens typically at the first time the Cell was instantiated.