显示时，UIActionSheet不会响应触摸

Question

我正在MonoTouch中编写移动应用程序。我的一个ViewControllers是一个设置页面，允许用户设置他们可以在地图视图上自定义的一些内容。其中之一是Pin颜色。我有12种颜色的引脚，并决定使用UIPickerView来呈现选择。客户希望用户在找到他们想要的颜色时必须点击“完成”按钮。为此我创建了一个UIToolBar并在其上放置了取消和完成按钮。工具栏直接显示在UIPickerView上方。我将PickerView和工具栏放在UIActionSheet上，并在用户点击PinColor文本字段时显示ActionSheet。

到目前为止，所有这一切都有效。当用户单击引脚颜色文本字段时，将显示操作工作表，并且选取器视图和工具栏可见，以及它们应在何处。问题是，我无法与任何按钮或选择器视图进行交互。这就像在行动表前面有一个viewcontroller，但我无法看到我在做的任何地方。有人可以看看下面的代码，如果你看到了什么让我知道吗？这只是我的viewcontroller代码的一部分，因此可能会缺少某些内容。但是，我的代码已经完成，编译得很好。

public override void ViewDidLoad ()
{
    base.ViewDidLoad ();
    tmpRect = new RectangleF(0,-220,this.View.Bounds.Width,220);
    myActionSheet = new UIActionSheet(tmpRect);
    myActionSheet.Style = UIActionSheetStyle.Default;
    myActionSheet.DestructiveButtonIndex = 0;
    myActionSheet.DismissWithClickedButtonIndex(0,true);
    settingsScrollView.AddSubview(myActionSheet);

    tmpRect = new RectangleF(0,-220,this.View.Bounds.Width,40);
    myToolbar = new UIToolbar(tmpRect);
    myToolbar.BarStyle = UIBarStyle.Black;
    myToolbar.Translucent = true;
    myToolbar.UserInteractionEnabled = true;
    myToolbar.SizeToFit();

    UIBarButtonItem btnLeft = new UIBarButtonItem(UIBarButtonSystemItem.Cancel, PickerButtonCancelHandler);
    UIBarButtonItem btnFlexibleSpace = new UIBarButtonItem(UIBarButtonSystemItem.FlexibleSpace, null);
    UIBarButtonItem btnDone = new UIBarButtonItem(UIBarButtonSystemItem.Done, PickerButtonDoneHandler);
    UIBarButtonItem[] items = new UIBarButtonItem[] { btnLeft, btnFlexibleSpace, btnDone }; 
    myToolbar.SetItems(items, true);
    myActionSheet.AddSubview(myToolbar);

    tmpRect = new RectangleF(0,-176, this.View.Bounds.Width,200);
    pvPinColor = new UIPickerView(tmpRect);
    MyPicker _pinPicker = new MyPicker();
    _pinPicker.Items.Add("Azure");
    _pinPicker.Items.Add("Black");
    _pinPicker.Items.Add("Blue");
    _pinPicker.Items.Add("Chartreuse");
    _pinPicker.Items.Add("Green");
    _pinPicker.Items.Add("Grey");
    _pinPicker.Items.Add("Orange");
    _pinPicker.Items.Add("Pink");
    _pinPicker.Items.Add("Red");
    _pinPicker.Items.Add("Violet");
    _pinPicker.Items.Add("White");
    _pinPicker.Items.Add("Yellow");
    pvPinColor.Source = _pinPicker;
    pvPinColor.UserInteractionEnabled = true;
    pvPinColor.ShowSelectionIndicator = true;
    myActionSheet.AddSubview(pvPinColor);
    settingsScrollView.AddSubview(txtPinColor);

    txtPinColor.EditingDidBegin += delegate {
        txtPinColor.ResignFirstResponder();
        txtPinColor.InputView = pvPinColor;
        myActionSheet.ShowInView(settingsScrollView);
        myActionSheet.UserInteractionEnabled = true;
        myActionSheet.BecomeFirstResponder();
        settingsScrollView.BringSubviewToFront(myActionSheet);

        _pinPicker.ValueChanged += (sender, e) => {
            if (File.Exists (pinFilePath)) { File.Delete(pinFilePath); }
            File.WriteAllText(pinFilePath, _pinPicker.SelectedItem);
            txtPinColor.Text = _pinPicker.SelectedItem;
            //pvPinColor.Hidden = true;
        };
    };
       }

public class MyPicker : UIPickerViewModel
{
public event EventHandler<EventArgs> ValueChanged;

public List<string> Items
{
    get { return this._items;} 
    set { this._items = value;}
}
List<string> _items = new List<string>();

public string SelectedItem
{
    get { return this._items[this._selectedIndex]; }
}
protected int _selectedIndex = 0;

public MyPicker()
{   
}

public override int GetRowsInComponent (UIPickerView picker, int component)
{
    return this._items.Count;
}

public override string GetTitle (UIPickerView picker, int row, int component)
{
    return this._items[row];
}

public override int GetComponentCount (UIPickerView picker)
{
    return 1;
}

public override void Selected (UIPickerView picker, int row, int component)
{
    this._selectedIndex = row;
      if (this.ValueChanged != null)
      {
        this.ValueChanged (this, new EventArgs());
   }
}
}