Merge pull request '添加文本重做功能' (#18) from fancanyu_branch into master

src/Notes-master/app/src/main/java/net/micode/notes/command/CommandManager.java

@@ -61,4 +61,12 @@ public class CommandManager {
         mUndoStack.clear();
         mRedoStack.clear();
     }
+    public void redo() {
+        if (canRedo()) {
+            Command command = mRedoStack.pop();
+            command.execute();
+            mUndoStack.push(command);
+        }
+    }
+
 }