public override bool IsApplicable(IObjectValueRole <TValue> valueRole, IMetadataTypeLite instanceType,
IPresentationOptions options,
IUserDataHolder dataHolder)
{
// Note that DebuggerDisplayObjectPresenter checks options.AllowTargetInvoke here
return(myUnityOptions.ExtensionsEnabled && options.AllowDebuggerDisplayEvaluation &&
TryCacheDebuggerDisplay(valueRole, instanceType.GetGenericTypeDefinition(), dataHolder));
}
// Return null to allow other providers a chance. If we throw EvaluatorException, it will be presented to the
// user. OperationCancelledException will be logged and we move on to the next presenter. Any other exception
// will leak
public override IValuePresentation PresentValue(IObjectValueRole <TValue> valueRole,
IMetadataTypeLite instanceType,
IPresentationOptions options,
IUserDataHolder dataHolder,
CancellationToken token)
{
var debuggerDisplayString = dataHolder.GetData(ourDebuggerDisplayStringKey);
try
{
var valueReference = valueRole.ValueReference;
var thisObj = valueReference.GetValue(options);
var evaluationOptions =
valueReference.OriginatingFrame.DebuggerSession.Options.EvaluationOptions.Apply(options);
// This can throw if there are members missing, which is entirely possible when debugging on a device,
// due to stripping. It will throw EvaluatorException. Anything else is logged and thrown as a new
// EvaluatorException. We can also get InvalidOperationException, but only if no other evaluators can
// handle the current context, which is unlikely
var displayString =
ExpressionEvaluators.EvaluateDisplayString(valueReference.OriginatingFrame, thisObj,
debuggerDisplayString, evaluationOptions, token);
return(SimplePresentation.CreateSuccess(
ValuePresentationPart.Default(DisplayStringUtil.EscapeString(displayString)),
valueReference.DefaultFlags, instanceType, displayString));
}
catch (Exception ex)
{
// Log as warning, not error - there's nothing the user can do, and we're likely to encounter this with
// device builds
myLogger.Warn(ex,
comment: $"Unable to evaluate debugger display string for type ${instanceType.GetGenericTypeDefinition().FullName}: ${debuggerDisplayString}. " +
"Expected behaviour on devices due to stripping");
return(null);
}
}
