XAMARIN信息：System.ArgumentException「jobject」一定不能IntPtr.Zero

Question

在XAMARIN，與MVVM方法有時當用戶穿越回我們得到一個錯誤的列表視圖，

System.ArgumentException: 'jobject' must not be IntPtr.Zero. 
Parameter name: jobject 
    at at Android.Runtime.JNIEnv.CallNonvirtualIntMethod (intptr,intptr,intptr) <IL 0x0001f, 0x000d8> 
    at at Android.Views.View.get_Visibility() <IL 0x00075, 0x002a3> 
    at at Xamarin.Forms.Platform.Android.VisualElementTracker.UpdateIsVisible() <IL 0x00021, 0x00127> 
    at at Xamarin.Forms.Platform.Android.VisualElementTracker.HandlePropertyChanged (object,System.ComponentModel.PropertyChangedEventArgs) <IL 0x002b3, 0x010d3> 
    at at (wrapper delegate-invoke) <Module>.invoke_void_object_PropertyChangedEventArgs (object,System.ComponentModel.PropertyChangedEventArgs) <IL 0x00044, 0x0009f> 
    at at Xamarin.Forms.BindableObject.OnPropertyChanged (string) <IL 0x00012, 0x000c7> 
    at at Xamarin.Forms.BindableObject.SetValueActual (Xamarin.Forms.BindableProperty,object,bool,bool,bool) <IL 0x000a3, 0x004f3> 
    at at Xamarin.Forms.BindableObject.SetValueCore (Xamarin.Forms.BindableProperty,object,bool,bool,bool) <IL 0x00213, 0x00aeb> 
    at at Xamarin.Forms.BindingExpression.ApplyCore (object,Xamarin.Forms.BindableObject,Xamarin.Forms.BindableProperty,bool) <IL 0x00206, 0x01287> 
    at at Xamarin.Forms.BindingExpression.Apply (bool) <IL 0x00041, 0x0018b> 
    at at Xamarin.Forms.BindingExpression/BindingExpressionPart.<PropertyChanged>b__12() <IL 0x00007, 0x00053> 
    at at Java.Lang.Thread/RunnableImplementor.Run() <IL 0x00011, 0x00097> 
    at at Java.Lang.IRunnableInvoker.n_Run (intptr,intptr) <IL 0x0000a, 0x000a3> 
    at at (wrapper dynamic-method) object.77d235ff-7394-41cf-b895-17e2737816c1 (intptr,intptr) <IL 0x00011, 0x0003b> 

Answer 1

的原因是少數視圖模型列表項目屬性，其中有空值，一旦我們確保所有的視圖模型屬性填充，這個錯誤得到解決。