Diagnostics Warning STRDIAG006

Invalid DataMemberMode for the specified [DataMember] member '{0}'. A public/internal/internal protected setter is required for 'DataMemberMode.Assign'.

Explanation

The Assign let's the serializers create new objects and sets them into the target property. The Property needs an accessible/visible setter.

Example: Invalid Cases

The following example generates STRDIAG006:

using Stride.Core;

public class STRDIAG006
{
    // non existent setters count as non visible
    [DataMember(DataMemberMode.Assign)]
    public int Property1 { get; }

    [DataMember(DataMemberMode.Assign)]
    public int Property2 { get; private set; }
    
    [DataMember(DataMemberMode.Assign)]
    public int Property3 { get; protected set; }
    
    [DataMember(DataMemberMode.Assign)]
    public int Property4 { get; private protected set; }
}

Example: Special Case internal

Important

To explicitly set the DataMemberMode.Assign the DataMemberAttribute has to be applied. Internal visibility counts then as visible for the serializers and becomes valid.

using Stride.Core;

public class STRDIAG006
{
    // non existent setters count as non visible
    [DataMember(DataMemberMode.Assign)]
    public int Property1 { get; internal set; }

    [DataMember(DataMemberMode.Assign)]
    public int Property2 { get; internal protected set; }
}

Solution

To resolve the warning, increase the accessibility of the properties set to public/internal. Or remove the explicit DataMemberMode.Assign, this can result in the DataMemberMode.Content, if the property is a non valuetype/string type.

References

• Serialisation