Merge pull request #1021 from Wanglongzhi2001/master

Finish EarlyStopping

Author: Oceania2018

src/TensorFlowNET.Core/Keras/Layers/ILayer.cs

@@ -17,7 +17,7 @@ public interface ILayer: IWithTrackable, IKerasConfigable
         List<IVariableV1> TrainableVariables { get; }
         List<IVariableV1> TrainableWeights { get; }
         List<IVariableV1> NonTrainableWeights { get; }
-        List<IVariableV1> Weights { get; set}
+        List<IVariableV1> Weights { get; set; }
         Shape OutputShape { get; }
         Shape BatchInputShape { get; }
         TensorShapeConfig BuildInputShape { get; }

src/TensorFlowNET.Core/Operations/NnOps/RNNCell.cs

@@ -84,6 +84,8 @@ public abstract class RnnCell : ILayer, RNNArgs.IRnnArgCell
         protected bool built = false;
         public bool Built => built;
 
+        List<IVariableV1> ILayer.Weights { get => throw new NotImplementedException(); set => throw new NotImplementedException(); }
+
         public RnnCell(bool trainable = true,
             string name = null,
             TF_DataType dtype = TF_DataType.DtInvalid,

src/TensorFlowNET.Keras/Callbacks/Earlystopping.cs

@@ -102,8 +102,8 @@ public void on_epoch_end(int epoch, Dictionary<string, float> epoch_logs)
                 {
                     Console.WriteLine($"Restoring model weights from the end of the best epoch: {_best_epoch + 1}");
                 }
+                _parameters.Model.Weights = _best_weights;
             }
-            _parameters.Model.Weights = _best_weights;
         }
     }
     public void on_train_end()