优化GaugeChart和RingChart的label初始化

Assets/XCharts/Editor/RingChartEditor.cs

@@ -0,0 +1,28 @@
+/******************************************/
+/*                                        */
+/*     Copyright (c) 2018 monitor1394     */
+/*     https://github.com/monitor1394     */
+/*                                        */
+/******************************************/
+
+using UnityEditor;
+
+namespace XCharts
+{
+    /// <summary>
+    /// Editor class used to edit UI RingChart.
+    /// </summary>
+
+    [CustomEditor(typeof(RingChart), false)]
+    public class RingChartEditor : BaseChartEditor
+    {
+        protected SerializedProperty m_Radar;
+        protected SerializedProperty m_Radars;
+
+        protected override void OnEnable()
+        {
+            base.OnEnable();
+            m_Target = (RingChart)target;
+        }
+    }
+}