【发布时间】：2016-05-29 04:16:09
【问题描述】：
我遇到了与此提交中确定的完全相同的问题： MvvmCross/Xamarin "This class is not key value coding-compliant for the key"
问题源于尝试在 IOS CollectionView 中使用 MVVMCross 数据绑定
那篇文章已关闭并标记为重复，但我不这么认为。它作为解决方案链接到的文章提供了将 XCode 用作开发环境时的解决方法。我的场景和上面链接的问题中描述的场景是在 Windows 上使用 Visual Studio 和 Xamarin 进行构建。使用 Visual Studio，XIB 编辑器和连接插座的方式有所不同。
我这几天一直在尝试解决这个问题，但没有解决任何问题。我希望在 Windows Visual Studio 中看到这一点的人有一个可以分享的解决方案。
（抱歉，我是新手，所以无法在原帖中发表评论）。
错误的堆栈跟踪如下
Foundation.MonoTouchException: Objective-C exception thrown.
Name: NSUnknownKeyException Reason: [<NSObject 0x7c4eb9a0> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key view.
Native stack trace:
0 CoreFoundation 0x00928494 __exceptionPreprocess + 180
1 libobjc.A.dylib 0x08fa3e02 objc_exception_throw + 50
2 CoreFoundation 0x009280b1 -[NSException raise] + 17
3 Foundation 0x014477f8 -[NSObject(NSKeyValueCoding) setValue:forUndefinedKey:] + 282
4 Foundation 0x013a1e6a _NSSetUsingKeyValueSetter + 115
5 Foundation 0x013a1def -[NSObject(NSKeyValueCoding) setValue:forKey:] + 295
6 Foundation 0x013d654b -[NSObject(NSKeyValueCoding) setValue:forKeyPath:] + 384
7 UIKit 0x03bc8a62 -[UIRuntimeOutletConnection connect] + 132
8 libobjc.A.dylib 0x08fb800c -[NSObject performSelector:] + 62
9 CoreFoundation 0x00851131 -[NSArray makeObjectsPerformSelector:] + 273
10 UIKit 0x03bc70fc -[UINib instantiateWithOwner:options:] + 2102
11 UIKit 0x041205ec -[UICollectionView _dequeueReusableViewOfKind:withIdentifier:forIndexPath:viewCategory:] + 750
12 UIKit 0x04120f35 -[UICollectionView dequeueReusableCellWithReuseIdentifier:forIndexPath:] + 194
13 ??? 0x1b909f9c 0x0 + 462462876
14 ??? 0x1be1b820 0x0 + 467777568
15 ??? 0x1be1b633 0x0 + 467777075
16 ??? 0x1be1adf6 0x0 + 467774966
17 ??? 0x1be1b08d 0x0 + 467775629
18 CompanionForSpotifyiOS 0x001bb2a1 mono_jit_runtime_invoke + 705
19 CompanionForSpotifyiOS 0x00276fef mono_runtime_invoke + 127
20 CompanionForSpotifyiOS 0x0034bb77 xamarin_trampoline + 5559
21 UIKit 0x0410d5ee -[UICollectionView _createPreparedCellForItemAtIndexPath:withLayoutAttributes:applyAttributes:isFocused:] + 448
22 UIKit 0x0410d2ff -[UICollectionView _createPreparedCellForItemAtIndexPath:withLayoutAttributes:applyAttributes:] + 65
23 UIKit 0x04111761 -[UICollectionView _updateVisibleCellsNow:] + 6023
24 UIKit 0x041167df -[UICollectionView layoutSubviews] + 254
25 UIKit 0x038543d4 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 810
26 libobjc.A.dylib 0x08fb8059 -[NSObject performSelector:withObject:] + 70
27 QuartzCore 0x0b5d8096 -[CALayer layoutSublayers] + 144
28 QuartzCore 0x0b5cb8b6 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 388
29 QuartzCore 0x0b5cb71a _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 26
30 QuartzCore 0x0b5bdee7 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 317
31 QuartzCore 0x0b5f2847 _ZN2CA11Transaction6commitEv + 561
32 QuartzCore 0x0b5f3108 _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 92
33 CoreFoundation 0x0083a75e __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 30
34 CoreFoundation 0x0083a6be __CFRunLoopDoObservers + 398
ViewModel 代码在这里
public partial class AlbumCell : MvxCollectionViewCell
{
public static readonly UINib Nib = UINib.FromName("AlbumCell", NSBundle.MainBundle);
public static readonly NSString Key = new NSString("AlbumCell");
public AlbumCell(IntPtr handle) : base(string.Empty, handle)
{
this.DelayBind(() =>
{
var set = this.CreateBindingSet<AlbumCell, Album>();
set.Bind(artistNameLabel).To(album => album.ArtistName);
set.Apply();
});
}
public static AlbumCell Create()
{
return (AlbumCell)Nib.Instantiate(null, null)[0];
}
}
这是生成的具有出口的视图模型组件 [注册（“专辑单元”）] 部分类 AlbumCell { [出口] [GeneratedCode ("iOS Designer", "1.0")] UILabel 艺术家姓名标签 { 获取；放; }
void ReleaseDesignerOutlets ()
{
if (artistNameLabel != null) {
artistNameLabel.Dispose ();
artistNameLabel = null;
}
}
}
最后，这是一个非常基础的 XIB - 它只有一个标签
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<document type="com.apple.InterfaceBuilder3.CocoaTouch.XIB" version="3.0" toolsVersion="10117" systemVersion="15F34" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES">
<dependencies>
<plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="10085"/>
</dependencies>
<objects>
<placeholder placeholderIdentifier="IBFilesOwner" id="-1" userLabel="File's Owner" customClass="AlbumCell">
<connections>
<outlet property="view" destination="2" id="RRd-Eg-VrN"/>
</connections>
</placeholder>
<placeholder placeholderIdentifier="IBFirstResponder" id="-2" customClass="UIResponder"/>
<view contentMode="scaleToFill" id="2">
<rect key="frame" x="0.0" y="0.0" width="600" height="600"/>
<subviews>
<label opaque="NO" clipsSubviews="YES" userInteractionEnabled="NO" contentMode="left" fixedFrame="YES" text="Label" lineBreakMode="tailTruncation" minimumFontSize="10" translatesAutoresizingMaskIntoConstraints="NO" id="5">
<rect key="frame" x="279" y="95" width="42" height="21"/>
<color key="backgroundColor" white="0.0" alpha="0.0" colorSpace="calibratedWhite"/>
<fontDescription key="fontDescription" type="system" pointSize="17"/>
<color key="textColor" cocoaTouchSystemColor="darkTextColor"/>
<nil key="highlightedColor"/>
</label>
</subviews>
<color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
</view>
</objects>
</document>
下面是我从父 ViewController 创建单元格对象实例的代码
public partial class NewReleasesView : MvxCollectionViewController
{
public NewReleasesView()
: base(new UIKit.UICollectionViewFlowLayout()
{
ItemSize = new CoreGraphics.CGSize(250,200),
ScrollDirection = UICollectionViewScrollDirection.Vertical
})
{
}
public override void ViewDidLoad()
{
base.ViewDidLoad();
CollectionView.RegisterNibForCell(AlbumCell.Nib, AlbumCell.Key);
var source = new MvxCollectionViewSource(CollectionView, AlbumCell.Key);
CollectionView.Source = source;
var set = this.CreateBindingSet<NewReleasesView, NewReleasesViewModel>();
set.Bind(source).To(vm => vm.NewReleases);
set.Apply();
CollectionView.ReloadData();
var viewModel = this.ViewModel as IMvxViewModel;
viewModel.Start();
}
}
【问题讨论】：
-
检查您的网点。当您从代码中删除 outlet 属性但没有从 Storyboard 中删除连接时，就会发生这种情况。
-
您能发布更多关于异常消息的详细信息吗？那是什么课？关键是什么？你有堆栈跟踪吗？您的应用在哪一行崩溃了？
-
@Paulw11，我在描述中添加了编码示例和调用堆栈。谢谢！！
-
异常表示您有一个
NSObject的实例，而不是 AlbumCell。你能显示你在哪里创建单元实例的代码吗？ -
@Paulw11，我已经用 ViewController 代码更新了上面的帖子，该代码具有创建单元对象的配置。
标签： ios xamarin visual-studio-2015 mvvmcross