not all code paths return a value - StrategyBaseConverter

[PaulMohn]

I'm getting this compile error:

NinjaScript File Error Code Line Column
MyXConverterStrat.cs 'NinjaTrader.NinjaScript.Strategies.MyXConverterSt rat.GetProperties(System.Component Model.ITypeDescriptorContext, object, System.Attribute[])': not all code paths return a value CS0161 9206 49

From similar code as at the bottom of this post, at this line:

public override PropertyDescriptorCollection GetProperties(ITypeDescriptorContext context, object component, Attribute[] attrs)

What's causing the error and what's the fix?

I checked this prior answer
ref. https://forum.ninjatrader.com/forum/ninjatrader-7/general-development/67251-error-cs0161-not-all-code-paths-return-a-value
which doesn't seem to pinpoint the issue since
the public bool MyX() method does return false outside the if statement.


Ref. https://forum.ninjatrader.com/forum/...44#post1315244

namespace NinjaTrader.NinjaScript.[B]Strategies[/B]
{
    [TypeConverter("NinjaTrader.NinjaScript.Strategies.MyXConverter")]​

    public class MyXConverterStrat : [B]Strategy[/B]
    {​
        
        public bool MyX()
        {
            if(Cond0())
            {
                 return true;
             }
                
             return false;
          }
    }
}

#region ConverterStuff
    
    public class MyXConverter: StrategyBaseConverter
    {
        public override PropertyDescriptorCollection GetProperties(ITypeDescriptorContext context, object component, Attribute[] attrs)
        {
            MyXConverterStrat strategy = component as MyXConverterStrat; // need the same name as the Class name

            PropertyDescriptorCollection propertyDescriptorCollection = base.GetPropertiesSupported(context)
                                                                        ? base.GetProperties(context, component, attrs)
                                                                        : TypeDescriptor.GetProperties(component, attrs);

            if (strategy == null || propertyDescriptorCollection == null)
                return propertyDescriptorCollection;
                

            PropertyDescriptor UpSoundFile            = propertyDescriptorCollection["UpSoundFile"];
            
                
            // remove removable properties first
            
            propertyDescriptorCollection.Remove(UpSoundFile);

            // Add back in if...
                        
            if (strategy.MyX())
            {
                propertyDescriptorCollection.Add(UpSoundFile);                                
            }
        
            return propertyDescriptorCollection;
        }
        
        // Important:  This must return true otherwise the type convetor will not be called
        public override bool GetPropertiesSupported(ITypeDescriptorContext context)
        { return true; }
    }        
    #endregion
}​

extra source:

https://stackoverflow.com/questions/21197410/c-sharp-compiler-error-not-all-code-paths-return-a-value

[PaulMohn]

Fix ( was missing at the end of public override PropertyDescriptorCollection GetProperties(ITypeDescriptorContext context, object component, Attribute[] attrs) method ):

return propertyDescriptorCollection;

}

// Important: This must return true otherwise the type convetor will not be called
public override bool GetPropertiesSupported(ITypeDescriptorContext context)
{ return true; }

[NinjaTrader_ChelseaB]

Hello PaulMohn,

The method return type is PropertyDescriptorCollection so a PropertyDescriptorCollection must be returned.

[PaulMohn]

NinjaTrader_ChelseaB Hello,

I'm getting this error:

NinjaScript File Error Code Line Column
MyEnum5.cs 'NinjaTrader.NinjaScript.Strategies.EnumtoLabelCon verter.ConvertTo(System.ComponentModel.ITypeDescri ptorContext, System.Globalization.CultureInfo, object, System.Type)': not all code paths return a value CS0161 271 33

What's causing this error "not all code paths return a value CS0161 271 33" From this script?

#region Using declarations
//using NinjaTrader.Cbi;
//using NinjaTrader.Core.FloatingPoint;
//using NinjaTrader.Data;
//using NinjaTrader.Gui.Chart;
//using NinjaTrader.Gui.SuperDom;
//using NinjaTrader.Gui.Tools;
//using NinjaTrader.Gui;
//using NinjaTrader.NinjaScript.DrawingTools;
//using NinjaTrader.NinjaScript.Indicators;
//using NinjaTrader.NinjaScript;
//using System.Collections.Generic;
//using System.ComponentModel.DataAnnotations;
//using System.ComponentModel;
//using System.Linq;
//using System.Text;
//using System.Threading.Tasks;
//using System.Windows.Input;
//using System.Windows.Media;
//using System.Windows;
//using System.Xml.Serialization;
//using System;



//using System.Collections.ObjectModel;
//using System.Collections;
//using System.Windows.Controls;
//using System.IO;
//using System.Reflection;

using NinjaTrader.Cbi;
using NinjaTrader.Core.FloatingPoint;
using NinjaTrader.Data;
using NinjaTrader.Gui.Chart;
using NinjaTrader.Gui.SuperDom;
using NinjaTrader.Gui;
using NinjaTrader.NinjaScript.DrawingTools;
using NinjaTrader.NinjaScript.Indicators;
using NinjaTrader.NinjaScript;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Collections;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows;
using System.Xml.Serialization;
using System;
#endregion

#region ENUMS

    public enum MyEnum5 // Strategies Buttons Selection
    {
        #region ENUMS STRATEGIES
        
            A,
            B,
            C,
        
            X,
            Y,
            Z,
        
        #endregion
    }

#endregion

//This namespace holds Strategies in this folder and is required. Do not change it.
namespace NinjaTrader.NinjaScript.Strategies
{
    
    public class _MyEnum5 : Strategy
    {
        
        #region #3 CLASS VARIABLES - State.SetDefaults : ENUM LOOP BUTTON LABEL == BUTTON ENUM STRING
            
            public static string btn1Lbl, btn2Lbl;

            // Create a variable that stores the user's selection for a moving average
            public static MyEnum5 st1EnumVar, nd2EnumVar;

        #endregion
        
        #region (OnStateChange)
        
            protected override void OnStateChange()
            {    
                #region (State == State.SetDefaults)
                
                    if (State == State.SetDefaults)
                    {
                        Description                                    = @"";
                        Name                                        = "_MyEnum5";
                        Calculate                                    = Calculate.OnBarClose;
                        EntriesPerDirection                            = 7;
                        EntryHandling                                = EntryHandling.AllEntries;
                        IsExitOnSessionCloseStrategy                = true;
                        ExitOnSessionCloseSeconds                    = 30;
                        IsFillLimitOnTouch                            = false;
                        
                        #region OnRender requires .Infinite
                        
                            MaximumBarsLookBack                        = MaximumBarsLookBack.Infinite;
                        
                        #endregion
                        
                        OrderFillResolution                            = OrderFillResolution.Standard;
                        Slippage                                    = 0;
                        StartBehavior                                = StartBehavior.ImmediatelySubmitSynchronizeAccount;
                        TimeInForce                                    = TimeInForce.Gtc;
                        TraceOrders                                    = false;
                        RealtimeErrorHandling                        = RealtimeErrorHandling.StopCancelClose;
                        StopTargetHandling                            = StopTargetHandling.PerEntryExecution;
                        BarsRequiredToTrade                            = 20;
                        // Disable this property for performance gains in Strategy Analyzer optimizations
                        // See the Help Guide for additional information
                        IsInstantiatedOnEachOptimizationIteration    = true;
                
                        #region BUTTONS PARAMETERS - BUTTONS METHOD ENUM SELECTORS
                
                            st1EnumVar                    = MyEnum5.X;
                            nd2EnumVar                    = MyEnum5.B;
                    
                        #endregion
                    
                        #region BUTTONS PARAMETERS
                            Button1Label                = Btn1Lbl;
                            
                            Button2Label                = Btn2Lbl;
                        
                        #endregion

                    }
                    
                #endregion
                
                #region (State == State.Configure)
                
                    else if (State == State.Configure)
                    {
                    }
                    
                #endregion
                
                #region (State == State.Historical)
                
                    else if (State == State.Historical)
                    {
                    }
                    
                #endregion
                    
                #region (State == State.Terminated)

                    else if (State == State.Terminated)
                    {
                    }
                    
                #endregion
            }
        
        #endregion
        
        #region REMOVE PARAMETERS LABELS FROM CHART

            public override string DisplayName
            {
                get {return this.Name;}
            }

        #endregion
        
        #region OnBarUpdate()
        
            protected override void OnBarUpdate()
            {
            }

        #endregion
        

        #region #2 PROPERTIES
        
            #region BUTTONS 1 TO 6

                #region Button 1 Parameters
                    
                    //[TypeConverter(typeof(EnumtoLabelConverter))]
                    [Display(Name="Methods 1", Description="", Order=1, GroupName="Parameters")]
                    [RefreshProperties(RefreshProperties.All)]
                    public static MyEnum5 St1EnumVar
                    { get; set; }
                
                    [NinjaScriptProperty]
                    [Display(Name="Label Button 1", Order=2, GroupName="Parameters")]
                    public string Button1Label
                    { get; set; }
                
                    [NinjaScriptProperty]
                    [Display(Name="Label Btn1Lbl ", Order=3, GroupName="Parameters")]
                    public static string Btn1Lbl
                    { get; set; }
                    
                #endregion
                
            
                #region Button 2 Parameters
                    
                    //[TypeConverter(typeof(EnumtoLabelConverter))]
                    [Display(Name="Methods 2", Description="", Order=4, GroupName="Parameters")]
                    [RefreshProperties(RefreshProperties.All)]
                    public static MyEnum5 Nd2EnumVar
                    { get; set; }
                
                    [NinjaScriptProperty]
                    [Display(Name="Label Button 2", Order=5, GroupName="Parameters")]
                    public string Button2Label
                    { get; set; }
                
                    [NinjaScriptProperty]
                    [Display(Name="Label Btn2Lbl", Order=6, GroupName="Parameters")]
                    public static string Btn2Lbl
                    { get; set; }
                    
                #endregion
        
            #endregion
            
        #endregion

        
                    
        
//        #region Use Case #4: Display "Friendly" enum values

//        [TypeConverter(typeof(EnumtoLabelConverter))] // Converts the enum to string values
//        [PropertyEditor("NinjaTrader.Gui.Tools.StringStandardValuesEditorKey")] // Enums normally automatically get a combo box, but we need to apply this specific editor so default value is automatically selected
//        [Display(Name = "Friendly Enum", Order = 10, GroupName = "Use Case #4")]
//        public MyEnum5 Nd2EnumVar
//        { get; set; }

//        #endregion
    }
    
    #region
        
        // Since this is only being applied to a specific property rather than the whole class,
        // we don't need to inherit from IndicatorBaseConverter and we can just use a generic TypeConverter
        public class EnumtoLabelConverter : TypeConverter
        {
            // Set the values to appear in the combo box
            public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)
            {
                List<string> values = new List<string>()
                { "A","B","C","X","Y","Z" };

                return new StandardValuesCollection(values);
            }

            // map the MyEnum type to "Friendly" string
            public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
            {
                MyEnum5 stringVal = (MyEnum5) Enum.Parse(typeof(MyEnum5), value.ToString());
            
                if (_MyEnum5.st1EnumVar == stringVal)
                    _MyEnum5.btn1Lbl = value.ToString();
                //else
                    //return string.Empty;
            }

            // required interface members needed to compile
            public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
            { return true; }

            public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
            { return true; }

            public override bool GetStandardValuesExclusive(ITypeDescriptorContext context)
            { return true; }

            public override bool GetStandardValuesSupported(ITypeDescriptorContext context)
            { return true; }
        }
        
    #endregion
}

At this line:

public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)

From the SampleIndicatorTypeConverter Use Case #4

https://pastecode.io/s/yty792rk

or the SampleStrategyTypeConverter Use Case #4

https://pastecode.io/s/jsbeh2ws

https://web.archive.org/web/20240827111419/https://paste.c-net.org/DiseaseConverts

I don't see extra return instructions:

    #region Use Case #4: Display "friendly" enum values
    public enum MyEnum
    {
        MyCustom1,
        MyCustom2,
        MyCustom3
    }

    // Since this is only being applied to a specific property rather than the whole class,
    // we don't need to inherit from IndicatorBaseConverter and we can just use a generic TypeConverter
    public class FriendlyEnumConverter : TypeConverter
    {
        // Set the values to appear in the combo box
        public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)
        {
            List<string> values = new List<string>() { "My custom one", "My custom two", "My custom three" };

            return new StandardValuesCollection(values);
        }

        // map the value from "Friendly" string to MyEnum type
        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
        {
            string stringVal = value.ToString();
            
            switch (stringVal)
            {
                case "My custom one":
                return MyEnum.MyCustom1;
                case "My custom two":
                return MyEnum.MyCustom2;
                case "My custom three":
                return MyEnum.MyCustom3;
            }
            return MyEnum.MyCustom1;
        }

        // map the MyEnum type to "Friendly" string
        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
        {
            MyEnum stringVal = (MyEnum) Enum.Parse(typeof(MyEnum), value.ToString());
            
            switch (stringVal)
            {
                case MyEnum.MyCustom1:
                return "My custom one";
                case MyEnum.MyCustom2:
                return "My custom two";
                case MyEnum.MyCustom3:
                return "My custom three";
            }
            return string.Empty;
        }

        // required interface members needed to compile
        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
        { return true; }

        public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
        { return true; }

        public override bool GetStandardValuesExclusive(ITypeDescriptorContext context)
        { return true; }

        public override bool GetStandardValuesSupported(ITypeDescriptorContext context)
        { return true; }
    }
    #endregion​

[NinjaTrader_ChelseaB]

Hello PaulMohn,

The method must return an object.

The SampleIndicatorTypeConverter reference sample returns a string.

// map the bool type to "Friendly" string
public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
{
return (bool) value ? "Turn on" : "Turn off";
}

[PaulMohn]

NinjaTrader_ChelseaB thanks,

That is from Use Case #3, not what I used. I used Use Case #4.

Here is use case #4 from the reduced SampleStrategyTypeConverter script:

//
// Copyright (C) 2018, NinjaTrader LLC <www.ninjatrader.com>.
// NinjaTrader reserves the right to modify or overwrite this NinjaScript component with each release.
//
#region Using declarations
using NinjaTrader.Cbi;
using NinjaTrader.Core.FloatingPoint;
using NinjaTrader.Data;
using NinjaTrader.Gui.Chart;
using NinjaTrader.Gui.SuperDom;
using NinjaTrader.Gui;
using NinjaTrader.NinjaScript.DrawingTools;
using NinjaTrader.NinjaScript.Indicators;
using NinjaTrader.NinjaScript;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Collections;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows;
using System.Xml.Serialization;
using System;
#endregion

//This namespace holds strategies in this folder and is required. Do not change it.
namespace NinjaTrader.NinjaScript.Strategies
{
    // Notes:
    // Helper classes and type converters are defined below the indicator, separated by use case
    // Property definitions are documented as necessary in the Properties region
    // Debugging issues will likely require compiling NS in debug mode and attaching VS to ninjatrader.exe
    // Setting breakpoints to examine values and seeing debug output that NT creates is helpful
    
    public class _SampleStrategyTypeConverter1 : Strategy
    {
        
        protected override void OnStateChange()
        {
            if (State == State.SetDefaults)
            {
                Description                                    = @"Demonstrating using type converters to customize the Indicator property grid";
                Name                                        = "_SampleStrategyTypeConverter1";
                Calculate                                    = Calculate.OnBarClose;
                EntriesPerDirection                            = 1;
                EntryHandling                                = EntryHandling.AllEntries;
                IsExitOnSessionCloseStrategy                = true;
                ExitOnSessionCloseSeconds                    = 30;
                IsFillLimitOnTouch                            = false;
                MaximumBarsLookBack                            = MaximumBarsLookBack.TwoHundredFiftySix;
                OrderFillResolution                            = OrderFillResolution.Standard;
                Slippage                                    = 0;
                StartBehavior                                = StartBehavior.WaitUntilFlat;
                TimeInForce                                    = TimeInForce.Gtc;
                TraceOrders                                    = false;
                RealtimeErrorHandling                        = RealtimeErrorHandling.StopCancelClose;
                StopTargetHandling                            = StopTargetHandling.PerEntryExecution;
                BarsRequiredToTrade                            = 20;
                // Disable this property for performance gains in Strategy Analyzer optimizations
                // See the Help Guide for additional information
                IsInstantiatedOnEachOptimizationIteration    = true;
                
                EnumValue         = MyEnumOne.MyCustom2;
            }
        }

        protected override void OnBarUpdate()
        {
        }

        #region Use Case #4: Display "Friendly" enum values

        [TypeConverter(typeof(FriendlyEnumConverter2))] // Converts the enum to string values
        // Enums normally automatically get a combo box, but we need to apply this specific editor so default value is automatically selected
        [PropertyEditor("NinjaTrader.Gui.Tools.StringStandardValuesEditorKey")]
        [Display(Name = "Friendly Enum", Order = 8, GroupName = "Use Case #4")]
        public MyEnumOne EnumValue
        { get; set; }

        #endregion
    }


    #region Use Case #4: Display "friendly" enum values
    public enum MyEnumOne
    {
        MyCustom1,
        MyCustom2,
        MyCustom3
    }

    // Since this is only being applied to a specific property rather than the whole class,
    // we don't need to inherit from IndicatorBaseConverter and we can just use a generic TypeConverter
    public class FriendlyEnumConverter2 : TypeConverter
    {
        // Set the values to appear in the combo box
        public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)
        {
            List<string> values = new List<string>() { "My custom one", "My custom two", "My custom three" };

            return new StandardValuesCollection(values);
        }

        // map the value from "Friendly" string to MyEnumOne type
        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
        {
            string stringVal = value.ToString();
            
            switch (stringVal)
            {
                case "My custom one":
                return MyEnumOne.MyCustom1;
                case "My custom two":
                return MyEnumOne.MyCustom2;
                case "My custom three":
                return MyEnumOne.MyCustom3;
            }
            return MyEnumOne.MyCustom1;
        }

        // map the MyEnumOne type to "Friendly" string
        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
        {
            MyEnumOne stringVal = (MyEnumOne) Enum.Parse(typeof(MyEnumOne), value.ToString());
            
            switch (stringVal)
            {
                case MyEnumOne.MyCustom1:
                return "My custom one";
                case MyEnumOne.MyCustom2:
                return "My custom two";
                case MyEnumOne.MyCustom3:
                return "My custom three";
            }
            return string.Empty;
        }

        // required interface members needed to compile
        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
        { return true; }

        public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
        { return true; }

        public override bool GetStandardValuesExclusive(ITypeDescriptorContext context)
        { return true; }

        public override bool GetStandardValuesSupported(ITypeDescriptorContext context)
        { return true; }
    }
    #endregion
}​

No return.
But this one does compile.

[PaulMohn]

I tested this but it still throws the error:

            // map the MyEnum type to "Friendly" string
            public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
            {
                MyEnum5 stringVal = (MyEnum5) Enum.Parse(typeof(MyEnum5), value.ToString());
            
                if (_MyEnum5.st1EnumVar == stringVal)
                    _MyEnum5.btn1Lbl = value.ToString();
                else
                    return string.Empty;
            }​

This compiles:

            // map the MyEnum type to "Friendly" string
            public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
            {
                MyEnum5 stringVal = (MyEnum5) Enum.Parse(typeof(MyEnum5), value.ToString());
                
                if (_MyEnum5.st1EnumVar == stringVal)
                {
                    _MyEnum5.btn1Lbl = value.ToString();
                    return _MyEnum5.btn1Lbl; // Return the label if the condition is met
                }
                
                return string.Empty; // Return an empty string if the condition is not met
            }​

[NinjaTrader_ChelseaB]

Hello PaulMohn,

if _MyEnum5.st1EnumVar is equal to stringVal what is returned?

[PaulMohn]

https://forum.ninjatrader.com/forum/ninjatrader-8/strategy-development/1315837-how-to-get-the-enum-s-inputs-displayed-on-the-strategy-prope