ios - SIGSEGV 错误 IOS - UITableView 上的 UiGestureRecognizer

Question

我有一个 UITableView，我将 UIGestureRecognizer 附加到带有自定义单元格的 ImageView。识别器在 tableview 的最后一行工作正常，但如果我尝试最后一行之前的任何单元格，应用程序会崩溃并出现以下错误。我不完全确定如何调试它，或者实际上这是否是我应该直接向 Xamarin 提出的问题。

感谢任何帮助。

using System;
using System.Drawing;

using MonoTouch.Foundation;
using MonoTouch.UIKit;
using System.Collections.Generic;

namespace gestures
{
public partial class gestureTest : UIViewController
{
    #region Private Variables
    private bool imageHighlighted = false;
    private bool touchStartedInside;
    #endregion


    public gestureTest () : base ("gestureTest", null)
    {
    }

    public override void DidReceiveMemoryWarning ()
    {
        // Releases the view if it doesn't have a superview.
        base.DidReceiveMemoryWarning ();

        // Release any cached data, images, etc that aren't in use.
    }

    public override void ViewDidLoad ()
    {
        base.ViewDidLoad ();



//          UIView viewGesture = new UIView ();
//
//          viewGesture.Add (tblGesture);

        fillTabele ();
        // Perform any additional setup after loading the view, typically from a nib.
    }



    protected void fillTabele( ) {



        List<WorkItem> list = new List<WorkItem>();
        list.Add (new WorkItem ("soemthing"));
        list.Add (new WorkItem ("soemthing else"));
        list.Add (new WorkItem ("soemthing other than else"));


        UITableView table = new UITableView(View.Bounds); // defaults to Plain style

        table.Source = new TableSource(list,"sptring",this);
        Add (table);

    }


    public class WorkItem  {

        public WorkItem() {}
        public WorkItem(string reftitle) {
            this.myTitle = reftitle;
        }

        private string myTitle;

        public string title
        {
            get 
            {
                return myTitle; 
            }
            set 
            { 
                myTitle = value; 
            }
        }
    }

    public class TableSource : UITableViewSource { 
        protected WorkItem[] 
        _tableItems; protected string _cellIdentifier = "TableCell"; 
        string vc; 
        UIImageView img; 
        UIViewController vController;
        UIAlertView alert; 
        UITapGestureRecognizer gesture = null; 
        //TaskViewController addTaskController;

        public TableSource(List<WorkItem> tblItemGroups, string sprint,UIViewController vCon)
        {
            this._tableItems = tblItemGroups.ToArray();
            this.vc = sprint;
            this.vController = vCon;
        }



        public override int RowsInSection(UITableView tableview, int section)
        {
            if (_tableItems != null)
            {
                return this._tableItems.Length;
            }
            else
            {
                return 0;
            }
        }
        public override UIView GetViewForHeader(UITableView tableView, int section)
        {

            return BuildSectionHeaderView(vc.ToString());
        }

        public static UIView BuildSectionHeaderView(string caption)
        {
            UIView view = new UIView(new System.Drawing.RectangleF(0, 0, 320, 20));
            UILabel label = new UILabel();
            label.BackgroundColor = UIColor.Clear;
            label.Opaque = false;
            label.TextColor = UIColor.Black;
            label.Font = UIFont.FromName("Helvetica-Bold", 16f);
            label.Frame = new System.Drawing.RectangleF(15, 0, 290, 20);
            label.Text = caption;
            view.AddSubview(label);
            return view;
        }
        public override float GetHeightForRow(UITableView tableView, NSIndexPath indexPath)
        {
            return 50f;
        }

        public override string TitleForHeader(UITableView tableView, int section)
        {

            return vc.ToString();
        }

        public static void ClearEmptyTableViewSpacer(UITableView oTableView)
        {
            UIView oViewSpacerClear = new UIView(new RectangleF(0, 0, oTableView.Frame.Width, 10));
            oViewSpacerClear.BackgroundColor = UIColor.Clear;
            oTableView.TableFooterView = oViewSpacerClear;

        }

        public override UITableViewCell GetCell(UITableView tableView, MonoTouch.Foundation.NSIndexPath indexPath)
        {

            if (UIDevice.CurrentDevice.UserInterfaceIdiom == UIUserInterfaceIdiom.Pad)
            {
                tableView.BackgroundView = null;
            }
            else
            {
                tableView.BackgroundColor = null;
            }
            WorkItem wrkitem = _tableItems[indexPath.Row];


            UITableViewCell cell = tableView.DequeueReusableCell(this._cellIdentifier);

            if (cell == null)
            {
                cell = new UITableViewCell(UITableViewCellStyle.Default, this._cellIdentifier);
            }


            NSAction action = () => {
                //alert=new UIAlertView("gesture recognized","tap me image tapped @" + gesture.LocationOfTouch (0, img).ToString (),null,"Ok","Cancel");
                alert=new UIAlertView("gesture recognized","tap me image tapped @",null,"Ok","Cancel");
                alert.Show();
            };

            cell.TextLabel.Text = wrkitem.title.ToString ();
            cell.ImageView.Image = UIImage.FromFile("images/splash-text.png");
            cell.ImageView.UserInteractionEnabled = true;
            gesture = new UITapGestureRecognizer();
            gesture.AddTarget(()=>action());
            cell.ImageView.AddGestureRecognizer(gesture);
            cell.ImageView.Frame = new RectangleF(10, 14, 5, 5);
            cell.TextLabel.Lines = 0;
            cell.TextLabel.LineBreakMode = UILineBreakMode.WordWrap;


            return cell;
        }


    }


    }
}

错误

mono-rt: Stacktrace:


mono-rt:   at <unknown> <0xffffffff>

mono-rt:   at (wrapper managed-to-native) MonoTouch.UIKit.UIApplication.UIApplicationMain      (int,string[],intptr,intptr) <IL 0x0009f, 0xffffffff>

mono-rt:   at MonoTouch.UIKit.UIApplication.Main (string[],string,string) [0x0004c] in /Developer/MonoTouch/Source/monotouch/src/UIKit/UIApplication.cs:38

mono-rt:   at gestures.Application.Main (string[]) [0x00008] in /Users/xxxxxx/Projects/gestures/gestures/Main.cs:17

mono-rt:   at (wrapper runtime-invoke) <Module>.runtime_invoke_void_object (object,intptr,intptr,intptr) <IL 0x00050, 0xffffffff>

mono-rt: 
Native stacktrace:


mono-rt: 
=================================================================
Got a SIGSEGV while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries 
used by your application.
=================================================================

!-- 单元格调整

        public override UITableViewCell GetCell(UITableView tableView, MonoTouch.Foundation.NSIndexPath indexPath)
        {

            if (UIDevice.CurrentDevice.UserInterfaceIdiom == UIUserInterfaceIdiom.Pad)
            {
                tableView.BackgroundView = null;
            }
            else
            {
                tableView.BackgroundColor = null;
            }
            WorkItem wrkitem = _tableItems[indexPath.Row];


            UITableViewCell cell = tableView.DequeueReusableCell(this._cellIdentifier);

            if (cell == null)
            {

                NSAction action = () => {
                    //alert=new UIAlertView("gesture recognized","tap me image tapped @" + gesture.LocationOfTouch (0, img).ToString (),null,"Ok","Cancel");
                    alert=new UIAlertView("gesture recognized","tap me image tapped @",null,"Ok","Cancel");
                    alert.Show();
                };

                cell = new UITableViewCell(UITableViewCellStyle.Default, this._cellIdentifier);

                cell.ImageView.UserInteractionEnabled = true;
                gesture = new UITapGestureRecognizer();
                gesture.AddTarget(()=>action());
                cell.ImageView.AddGestureRecognizer(gesture);
                cell.ImageView.Frame = new RectangleF(10, 14, 5, 5);
                cell.TextLabel.Lines = 0;
                cell.TextLabel.LineBreakMode = UILineBreakMode.WordWrap;

            }

            cell.TextLabel.Text = wrkitem.title.ToString ();
            cell.ImageView.Image = UIImage.FromFile("images/splash-text.png");

            return cell;
        }//


       *new error*

       2014-07-04 07:28:57.263 gestures[22619:1303] MonoTouch: Socket error while           connecting to MonoDevelop on 127.0.0.1:10000: Connection refused
  2014-07-04 07:29:16.139 gestures[22619:80b] -[__NSSetM target]: unrecognized selector sent to instance 0xe6ce030

  Unhandled Exception:
 MonoTouch.Foundation.MonoTouchException: Objective-C exception thrown.  Name:          NSInvalidArgumentException Reason: -[__NSSetM target]: unrecognized selector sent to instance       0xe6ce030
   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 gestures.Application.Main (System.String[] args) [0x00008] in /Users/xxxxxx/Projects/gestures/gestures/Main.cs:17 
 NSInvalidArgumentException: -[__NSSetM target]: unrecognized selector sent to instance       0xe6ce030
  0   CoreFoundation                      0x0161e5e4 __exceptionPreprocess + 180
1   libobjc.A.dylib                     0x04e898b6 objc_exception_throw + 44
2   CoreFoundation                      0x016bb903 -[NSObject(NSObject) doesNotRecognizeSelector:] + 275
3   CoreFoundation                      0x0160e90b ___forwarding___ + 1019
4   CoreFoundation                      0x0160e4ee _CF_forwarding_prep_0 + 14
5   UIKit                               0x02ccee8c _UIGestureRecognizerSendActions + 230
6   UIKit                               0x02ccdb00 -[UIGestureRecognizer _updateGestureWithEvent:buttonEvent:] + 383
7   UIKit                               0x02ccf56d -[UIGestureRecognizer _delayedUpdateGesture] + 60
8   UIKit                               0x02cd2acd ___UIGestureRecognizerUpdate_block_invoke + 57
9   UIKit                               0x02cd2a4e _UIGestureRecognizerRemoveObjectsFromArrayAndApplyBlocks + 317
10  UIKit                               0x02cc9148 _UIGestureRecognizerUpdate + 199
11  UIKit                               0x0299519a -[UIWindow _sendGesturesForEvent:] + 1291
12  UIKit                               0x029960ba -[UIWindow sendEvent:] + 1030
13  UIKit                               0x02969e86 -[UIApplication sendEvent:] + 242
14  UIKit                               0x0295418f _UIApplicationHandleEventQueue + 11421
15  CoreFoundation                      0x015a783f __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 15
16  CoreFoundation                      0x015a71cb __CFRunLoopDoSources0 + 235
17  CoreFoundation                      0x015c429e __CFRunLoopRun + 910
18  CoreFoundation                      0x015c3ac3 CFRunLoopRunSpecific + 467
19  CoreFoundation                      0x015c38db CFRunLoopRunInMode + 123
20  GraphicsServices                    0x060969e2 GSEventRunModal + 192
21  GraphicsServices                    0x06096809 GSEventRun + 104
22  UIKit                               0x02956d3b UIApplicationMain + 1225
23  ???                                 0x127f82ac 0x0 + 310346412
24  ???                                 0x127f713c 0x0 + 310341948
25  ???                                 0x127f6ec0 0x0 + 310341312
26  ???                                 0x127f6f4f 0x0 + 310341455
27  gestures                            0x000f655b mono_jit_runtime_invoke + 843
28  gestures                            0x00194b5f mono_runtime_invoke + 127
29  gestures                            0x0019a671 mono_runtime_exec_main + 401
30  gestures                            0x0019a434 mono_runtime_run_main + 628
31  gestures                            0x00054ffd mono_jit_exec + 93
32  gestures                            0x00235a70 main + 2784
33  gestures                            0x00003a15 start + 53

 2014-07-04 07:29:16.150 gestures[22619:80b] Unhandled managed exception: Objective-C    exception thrown.  Name: NSInvalidArgumentException Reason: -[__NSSetM target]: unrecognized     selector sent to instance 0xe6ce030 (MonoTouch.Foundation.MonoTouchException)
   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 gestures.Application.Main (System.String[] args) [0x00008] in  /Users/seankerr/Projects/gestures/gestures/Main.cs:17 

mono-rt:堆栈跟踪:

  mono-rt: 
  Native stacktrace:


  mono-rt:  0   gestures                            0x000c4777 mono_handle_native_sigsegv + 327

  mono-rt:  1   gestures                            0x000cf5ba sigabrt_signal_handler + 122

  mono-rt:  2   libsystem_platform.dylib            0x05427deb _sigtramp + 43

  mono-rt:  3   ???                                 0xffffffff 0x0 + 4294967295

  mono-rt:  4   libsystem_sim_c.dylib               0x05144e12 abort + 127

 mono-rt:   5   gestures                            0x0024db33    monotouch_unhandled_exception_handler + 291

 mono-rt:   6   gestures                            0x000c4fbb   mono_invoke_unhandled_exception_hook + 91

mono-rt:    7   gestures                            0x000c3fcc mono_handle_exception_internal + 6620

mono-rt:    8   gestures                            0x000c25e9 mono_handle_exception + 41

mono-rt:    9   gestures                            0x0005cdd9 mono_x86_throw_exception + 137   

mono-rt:    10  ???                                 0x0ee30e57 0x0 + 249761367

mono-rt:    11  gestures                            0x0023d001 monotouch_exception_handler + 177

mono-rt:    12  CoreFoundation                      0x016aea1d __handleUncaughtException + 749

mono-rt:    13  libobjc.A.dylib                     0x04e89b5c _ZL15_objc_terminatev + 100

mono-rt:    14  libc++abi.dylib                     0x0535df60 _ZSt11__terminatePFvvE + 14

 mono-rt:   15  libc++abi.dylib                     0x0535db97 __cxa_rethrow + 103

mono-rt:    16  libobjc.A.dylib                     0x04e89a57 objc_exception_rethrow + 47

mono-rt:    17  CoreFoundation                      0x015c3b55 CFRunLoopRunSpecific + 613

mono-rt:    18  CoreFoundation                      0x015c38db CFRunLoopRunInMode + 123

mono-rt:    19  GraphicsServices                    0x060969e2 GSEventRunModal + 192

mono-rt:    20  GraphicsServices                    0x06096809 GSEventRun + 104

mono-rt:    21  UIKit                               0x02956d3b UIApplicationMain + 1225

mono-rt:    22  ???                                 0x127f82ac 0x0 + 310346412

mono-rt:    23  ???                                 0x127f713c 0x0 + 310341948

mono-rt:    24  ???                                 0x127f6ec0 0x0 + 310341312

mono-rt:    25  ???                                 0x127f6f4f 0x0 + 310341455

mono-rt:    26  gestures                            0x000f655b mono_jit_runtime_invoke + 843

mono-rt:    27  gestures                            0x00194b5f mono_runtime_invoke + 127

mono-rt:    28  gestures                            0x0019a671 mono_runtime_exec_main + 401

 mono-rt:   29  gestures                            0x0019a434 mono_runtime_run_main + 628

 mono-rt:   30  gestures                            0x00054ffd mono_jit_exec + 93

  mono-rt:  31  gestures                            0x00235a70 main + 2784

  mono-rt:  32  gestures                            0x00003a15 start + 53

    mono-rt: 
  =================================================================
  Got a SIGABRT while executing native code. This usually indicates
  a fatal error in the mono runtime or one of the native libraries 
  used by your application.
  =================================================================

更新堆栈跟踪

mono-rt:   at <unknown> <0xffffffff>

mono-rt:   at (wrapper managed-to-native) MonoTouch.UIKit.UIApplication.UIApplicationMain   (int,string[],intptr,intptr) <IL 0x0009f, 0xffffffff>

mono-rt:   at MonoTouch.UIKit.UIApplication.Main (string[],string,string) [0x0004c] in /Developer/MonoTouch/Source/monotouch/src/UIKit/UIApplication.cs:38

mono-rt:   at gestures.Application.Main (string[]) [0x00008] in /Users/seankerr/Projects/gestures/gestures/Main.cs:17

mono-rt:   at (wrapper runtime-invoke) <Module>.runtime_invoke_void_object (object,intptr,intptr,intptr) <IL 0x00050, 0xffffffff>

mono-rt: 
Native stacktrace:


mono-rt: 
=================================================================
Got a SIGSEGV while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries 
used by your application.
=================================================================

最终更新

我采纳了@pnavk 的建议，重新开始了一个空白项目，使用 Xamarin 网站上的代码创建了基本项目，然后将 UIGestureRecognizer 添加到单元格中。

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

namespace gestures
{
public partial class gestureController : UIViewController
{
    public gestureController () : base ("gestureController", null)
    {
    }

    UITableView table;
    private string _caption = "caption";
    static NSString kCellIdentifier = new NSString ("MyIdentifier");
    static UIView cellView = new UIView (new RectangleF (325, 0, 320, 568));

    public override void DidReceiveMemoryWarning ()
    {
        // Releases the view if it doesn't have a superview.
        base.DidReceiveMemoryWarning ();

        // Release any cached data, images, etc that aren't in use.
    }

    public override void ViewDidLoad ()
    {
        base.ViewDidLoad ();
        table = new UITableView (View.Bounds); // defaults to Plain style

        string[] tableItems = new string[] { "Vegetables", "Fruits", "Flower Buds", "Legumes", "Bulbs", "Tubers" };
        table.Source = new TableSource (tableItems);
        Add (table);

        cellView.BackgroundColor = UIColor.Blue;
        View.Add (cellView);

        // Perform any additional setup after loading the view, typically from a nib.
    }

    public class TableSource : UITableViewSource
    {
        string[] tableItems;
        protected string _cellIdentifier = "TableCell";

        public TableSource (string[] items)
        {
            tableItems = items;
        }

        public override int RowsInSection (UITableView tableview, int section)
        {
            return tableItems.Length;
        }

        public override UITableViewCell GetCell (UITableView tableView, MonoTouch.Foundation.NSIndexPath indexPath)
        {
            CustomVegeCell cell = tableView.DequeueReusableCell (kCellIdentifier) as CustomVegeCell;
            if (cell == null)
                cell = new CustomVegeCell (kCellIdentifier);
            cell.UpdateCell (tableItems [indexPath.Row], tableItems [indexPath.Row], UIImage.FromFile ("splash-text.png"), cellView);
            return cell;
        }

    }
}

Answer 1

我将对您的代码进行以下更改:

if (UIDevice.CurrentDevice.UserInterfaceIdiom == UIUserInterfaceIdiom.Pad)
{
    tableView.BackgroundView = null;
}
else
{
    tableView.BackgroundColor = null;
}

这应该从 GetCell 移出并移入 ViewDidLoad 或 ViewWillAppear。 GetCell 方法被重复调用(当您滚动或重新加载数据时)和(我可能是不正确的)但这段代码看起来不需要多次调用。您还应该如前所述，在 ViewDidLoad 或 ViewWillAppear 中将图像初始化为全局变量(例如 myImage)并分配它，而不是一遍又一遍地加载它。

现在，不必每次都在 GetCell 中设置手势识别器，您可以创建自定义 UITableViewCell 并在自定义单元格的 AwakeFromNib 方法中在 ImageView 上实现手势识别器:

namespace gestures
{
    public partial class gestureTestCell : UITableViewCell
    {
        public static string _cellIdentifier = "gestureTestCell"; // whatever you name it in Interface Builder

        public gestureTestCell () : base ()
        {

        }

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

        }

        protected override void Dispose (bool disposing)
        {
            myImageView.RemoveGestureRecognizer(gesture)

            base.Dispose (disposing);
        }

        public override void AwakeFromNib ()
        {
            base.AwakeFromNib ();

            var gesture = new UITapGestureRecognizer (HandleTapGesture);
            myImageView.AddGestureRecognizer (gesture);
        }

        public override void LayoutSubviews ()
        {
            base.LayoutSubviews ();

            myImageView.UserInteractionEnabled = true;
            myImageView.Frame = new RectangleF(10, 14, 5, 5);
            myTextLabel.Lines = 0;
            myTextLabel.LineBreakMode = UILineBreakMode.WordWrap;
        }

       void HandleTapGesture (UITapGestureRecognizer gesture)
       {
        var alert = new UIAlertView("gesture recognized","tap me image tapped     @",null,"Ok","Cancel");
        alert.Show();
        }

        public override void PrepareForReuse ()
        {
            base.PrepareForReuse ();
        }


        public void SetupCell(string text, UIImage image)
        {
            myImageView.Image = image;
            myTextLabel.Text  = text;   
        }
    }
  }

现在您的 GetCell 方法看起来像这样:

public override UITableViewCell GetCell(UITableView tableView, MonoTouch.Foundation.NSIndexPath indexPath)
{
    gestureTestCell cell = tableView.DequeueReusableCell(gestureTestCell._cellIdentifier) ?? new gestureTestCell();

    cell.SetupCell(_tableItems[indexPath.Row].ToString(), myImage);

    return cell;
}