Xamarin.Forms Picker causes app to crash

Question

I have the following code set up. The simulator crashes when I navigate to the view. I am trying to put a picker into my app that displays pay schedules such as Weekly, Semi-Annual, and Annual.

    insurancePicker = new Picker() 
    {
        Title = "Insurance Frequency",
        VerticalOptions = LayoutOptions.FillAndExpand
    };
    insurancePicker.Items.Add("Monthly");
    insurancePicker.Items.Add("Semi-Annual");
    insurancePicker.Items.Add("Annual");              
    insurancePicker.SelectedIndexChanged += (sender, args) =>
    {
        if (insurancePicker.SelectedIndex == -1)
        {               
        }
        else
        {
        }
    };

I add it to the view like such:

Content = new StackLayout{
            Spacing = 20, Padding = new Thickness(10, 10, 10, 0),
            Children = {
                homeValue,
                amountOwed,
                new StackLayout{
                    Spacing = 2,
                    Orientation = StackOrientation.Horizontal, 
                    Children = {
                        insurance,
                        insurancePicker
                    }
                },
                new StackLayout{
                    Spacing = 2,
                    Orientation = StackOrientation.Horizontal, 
                    Children = {
                        taxes,
                        taxesPicker
                    }
                },
                btnCalculate
            }
        };

Below is the stacktrace I get:

mono-rt: Stacktrace:

mono-rt: at <0xffffffff>

mono-rt: at (wrapper managed-to-native) MonoTouch.ObjCRuntime.Messaging.void_objc_msgSend_int_int_bool (intptr,intptr,int,int,bool)

mono-rt: at MonoTouch.UIKit.UIPickerView.Select (int,int,bool) [0x00010] in /Developer/MonoTouch/Source/monotouch/src/build/compat/UIKit/UIPickerView.g.cs:185

mono-rt: at Xamarin.Forms.Platform.iOS.PickerRenderer.UpdatePicker ()

mono-rt: at Xamarin.Forms.Platform.iOS.PickerRenderer.OnModelSet (Xamarin.Forms.VisualElement)

mono-rt: at Xamarin.Forms.Platform.iOS.ViewRenderer.SetModel (Xamarin.Forms.VisualElement)

mono-rt: at Xamarin.Forms.Platform.iOS.RendererFactory.GetRenderer (Xamarin.Forms.VisualElement)

mono-rt: at Xamarin.Forms.Platform.iOS.ViewPackager.HandleChildAdded (Xamarin.Forms.VisualElement)

mono-rt: at Xamarin.Forms.EnumerableExtensions.ForEach (System.Collections.Generic.IEnumerable1<T>,System.Action1)

mono-rt: at Xamarin.Forms.Platform.iOS.ViewPackager.Load ()

mono-rt: at Xamarin.Forms.Platform.iOS.ViewRenderer.SetUpEventHandlers (MonoTouch.UIKit.UIView)

mono-rt: at Xamarin.Forms.Platform.iOS.ViewRenderer.OnModelSet (Xamarin.Forms.VisualElement)

mono-rt: at Xamarin.Forms.Platform.iOS.ViewRenderer.SetModel (Xamarin.Forms.VisualElement)

mono-rt: at Xamarin.Forms.Platform.iOS.RendererFactory.GetRenderer (Xamarin.Forms.VisualElement)

mono-rt: at Xamarin.Forms.Platform.iOS.ViewPackager.HandleChildAdded (Xamarin.Forms.VisualElement)

mono-rt: at Xamarin.Forms.EnumerableExtensions.ForEach (System.Collections.Generic.IEnumerable1<T>,System.Action1)

mono-rt: at Xamarin.Forms.Platform.iOS.ViewPackager.Load ()

mono-rt: at Xamarin.Forms.Platform.iOS.ViewRenderer.SetUpEventHandlers (MonoTouch.UIKit.UIView)

mono-rt: at Xamarin.Forms.Platform.iOS.ViewRenderer.OnModelSet (Xamarin.Forms.VisualElement)

mono-rt: at Xamarin.Forms.Platform.iOS.ViewRenderer.SetModel (Xamarin.Forms.VisualElement)

mono-rt: at Xamarin.Forms.Platform.iOS.RendererFactory.GetRenderer (Xamarin.Forms.VisualElement)

mono-rt: at Xamarin.Forms.Platform.iOS.ViewPackager.HandleChildAdded (Xamarin.Forms.VisualElement)

mono-rt: at Xamarin.Forms.EnumerableExtensions.ForEach (System.Collections.Generic.IEnumerable1<T>,System.Action1)

mono-rt: at Xamarin.Forms.Platform.iOS.ViewPackager.Load ()

mono-rt: at Xamarin.Forms.Platform.iOS.PageRenderer.ViewDidLoad ()

mono-rt: at (wrapper runtime-invoke) object.runtime_invoke_void__this__ (object,intptr,intptr,intptr)

mono-rt: at <0xffffffff>

mono-rt: at (wrapper managed-to-native) MonoTouch.ObjCRuntime.Messaging.IntPtr_objc_msgSendSuper (intptr,intptr)

mono-rt: at MonoTouch.UIKit.UIViewController.get_View () [0x00030] in /Developer/MonoTouch/Source/monotouch/src/build/compat/UIKit/UIViewController.g.cs:2232

mono-rt: at Xamarin.Forms.Platform.iOS.NavigationRenderer/d__d.MoveNext ()

mono-rt: at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.Startd__d> (Xamarin.Forms.Platform.iOS.NavigationRenderer/d__d&) [0x0001b] in /Developer/MonoTouch/Source/mono/mcs/class/corlib/System.Runtime.CompilerServices/AsyncTaskMethodBuilder_T.cs:107

mono-rt: at Xamarin.Forms.Platform.iOS.NavigationRenderer.OnPushAsync (Xamarin.Forms.Page,bool)

mono-rt: at Xamarin.Forms.Platform.iOS.NavigationRenderer.PushPageAsync (Xamarin.Forms.Page,bool)

mono-rt: at Xamarin.Forms.Platform.iOS.NavigationRenderer.OnPushRequested (object,Xamarin.Forms.NavigationRequestedEventArgs)

mono-rt: at Xamarin.Forms.NavigationPage/d__c.MoveNext ()

mono-rt: at System.Runtime.CompilerServices.AsyncTaskMethodBuilder.Startd__c> (Xamarin.Forms.NavigationPage/d__c&) [0x0001b] in /Developer/MonoTouch/Source/mono/mcs/class/corlib/System.Runtime.CompilerServices/AsyncTaskMethodBuilder.cs:107

mono-rt: at Xamarin.Forms.NavigationPage.PushAsync (Xamarin.Forms.Page)

mono-rt: at Xamarin.Forms.NavigationPage/NavigationImpl.OnPushAsync (Xamarin.Forms.Page)

mono-rt: at Xamarin.Forms.NavigationProxy.PushAsync (Xamarin.Forms.Page)

mono-rt: at Xamarin.Forms.NavigationProxy.OnPushAsync (Xamarin.Forms.Page)

mono-rt: at Xamarin.Forms.NavigationProxy.PushAsync (Xamarin.Forms.Page)

mono-rt: at FNBMortgageForms.Shared.HomePage.m__1 (object,System.EventArgs) [0x00010] in /Users/Projects/FNBMortgageForms/FNBMortgageForms/Views/HomePage.cs:59

mono-rt: at Xamarin.Forms.Button.SendClicked ()

mono-rt: at Xamarin.Forms.Platform.iOS.ButtonRenderer/<>c__DisplayClass1.b__0 (object,System.EventArgs)

mono-rt: at MonoTouch.UIKit.UIControlEventProxy.Activated () [0x00007] in /Developer/MonoTouch/Source/monotouch/src/UIKit/UIControl.cs:33

mono-rt: at (wrapper runtime-invoke) object.runtime_invoke_void__this__ (object,intptr,intptr,intptr)

mono-rt: at <0xffffffff>

mono-rt: at (wrapper managed-to-native) MonoTouch.UIKit.UIApplication.UIApplicationMain (int,string[],intptr,intptr)

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

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

mono-rt: at (wrapper runtime-invoke) .runtime_invoke_void_object (object,intptr,intptr,intptr)

mono-rt: Native stacktrace:

mono-rt:

You were correct. Was a copy paste error. I changed everything to be the taxesPicker except the part where you add items. Thanks! — Brandon Tripp

Stephane Delcroix Stephane Delcroix · Accepted Answer · 2014-07-01T08:12:08

You're filling Items for your insurancepicker but i don't see you filling taxespicker. The error reporting does not give you that information, but having at least one item set is required for a Picker to work.

Xamarin.Forms Picker causes app to crash

1 Answers