uipopover 控制器正在释放 monotouch

Question

我认为，我遇到了一个问题，即 UIPopoverController 在被解除之前被解除分配，这很奇怪，因为 UIPopoverController 是一个类变量。任何帮助将不胜感激。

这是错误，我得到了

MonoTouch.Foundation.MonoTouchException: Objective-C exception thrown.  Name: NSGenericException Reason: -[UIPopoverController dealloc] reached while popover is still visible.
  at at (wrapper managed-to-native) MonoTouch.Foundation.NSObject:monotouch_release_managed_ref (intptr)
  at MonoTouch.Foundation.NSObject.ReleaseManagedRef () [0x00000] in /Developer/MonoTouch/Source/monotouch/src/Foundation/NSObject.cs:99
  at MonoTouch.Foundation.NSObject+NSObject_Disposer.Drain (MonoTouch.Foundation.NSObject ctx) [0x00062] in /Developer/MonoTouch/Source/monotouch/src/shared/Foundation/NSObject2.cs:602
  at at (wrapper managed-to-native) MonoTouch.UIKit.UIApplication:UIApplicationMain (int,string[],intptr,intptr)
  at MonoTouch.UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x0004c] in /Developer/MonoTouch/Source/monotouch/src/UIKit/UIApplication.cs:38
  at Lab_assistant.Application.Main (System.String[] args) [0x00008] in /working/Lab_assistant/Main.cs:17

这是课程，我正在学习

using System.Drawing;
using MonoTouch.Foundation;
using MonoTouch.UIKit;

namespace Lab_assistant
{
[Register("ViewView")]
public class ViewView:UIView
{
    public  Block _b { set; get;}
    public EventHandler _touched;
    private UIView _popViewText;
    private UIViewController _Controller;
    private UIPopoverController _popUp;
    Boolean edit;

    public ViewView (Block b,BlockManger.Del TheMethod)
    {
        _b = b;
        this.Frame = b._location;
        this.BackgroundColor = UIColor.White;
        this.AddGestureRecognizer (new UILongPressGestureRecognizer (tapped));
        TheMethod (_b,this);
        this.Frame = new System.Drawing.RectangleF(b._location.Location, new System.Drawing.SizeF (b._location.Width, b._location.Height + 2));
    }

    [Export("tapped")]
    protected void tapped(UIGestureRecognizer sender)
    {
        TouchOccoured ();
    }

    public void Edit()
    {
        UIButton btn = new UIButton (UIButtonType.RoundedRect);
        _popViewText = new UIView(new System.Drawing.RectangleF(new System.Drawing.PointF(0,0), new System.Drawing.SizeF(200,200)));
        _popViewText.BackgroundColor = UIColor.DarkGray;
        btn.Hidden = false;
        btn.Frame = new System.Drawing.RectangleF(new System.Drawing.PointF(0,31),new System.Drawing.SizeF(100,30));
        btn.SetTitle ("Remove", UIControlState.Normal);

        UIButton btn2 = new UIButton (UIButtonType.RoundedRect);
        btn2.Hidden = false;
        btn2.Frame = new System.Drawing.RectangleF(new System.Drawing.PointF(0,0),new System.Drawing.SizeF(100,30));
        btn2.SetTitle ("Resize", UIControlState.Normal);

        _popViewText.AddSubview (btn);
        _popViewText.AddSubview (btn2);
        _Controller = new UIViewController ();
        _Controller.Add (_popViewText);
        _popUp = new UIPopoverController(_Controller);

        btn.TouchUpInside += (object sender, EventArgs e) => 
        {
            this.RemoveFromSuperview(); 
            edit = false;
        };
    }

    public void EditBlock()
    {
        if (!edit)
        {
            edit = true;
            _popUp.PopoverContentSize = new SizeF (200, 200);
            _popUp.PresentFromRect (new System.Drawing.RectangleF (new PointF(0,0), new System.Drawing.SizeF (20, 20)), this, UIPopoverArrowDirection.Left, true);
            //_popViewText = new UIView (rec);
        }
    }

    public void TouchOccoured()
    {
        if(_touched != null)
        {
            this.Edit ();
            this.EditBlock ();

            _touched (this, null);
        }
    }
}
}

非常感谢您的帮助

Answer 1

我打赌Edit 被多次调用，导致多个UIPopoverController 被实例化。如果是这种情况，您可以使用以下方法修复它：

public void Edit ()
{
    if (_popup != null && _popup.PopoverVisible) {
        _popup.Dismiss (false);
        _popup.Dispose();
    }

    //your code
}

Answer 2

几个想法：

• 确保Edit 只被调用一次。
• 确保ViewView 也没有被释放（您可以通过实现 Dispose 重载并在其中放置断点或 Console.WriteLine 来轻松做到这一点）。