添加了对Notes类的注释

app/src/main/java/net/micode/notes/data/Notes.java

@@ -67,6 +67,9 @@ public class Notes {
      */
     public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
 
+    /**
+     * 定义了NoteColumns中的常量,将用于后面创建数据库的表头
+     */
     public interface NoteColumns {
         /**
          * The unique ID for a row
@@ -172,6 +175,9 @@ public class Notes {
          */
         public static final String VERSION = "version";
     }
+    /**
+     * 以上这些常量主要是用于定义便签的属性
+     */
 
     public interface DataColumns {
         /**
@@ -245,7 +251,9 @@ public class Notes {
          * <P> Type: TEXT </P>
          */
         public static final String DATA5 = "data5";
-    }
+    }/**
+     *    以上DATA主要是定义存储便签内容数据
+     */
 
     public static final class TextNote implements DataColumns {
         /**
@@ -261,7 +269,9 @@ public class Notes {
         public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/text_note";
 
         public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/text_note");
-    }
+    }/**
+     *   文本内容的数据结构
+     */
 
     public static final class CallNote implements DataColumns {
         /**
@@ -281,5 +291,7 @@ public class Notes {
         public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/call_note";
 
         public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/call_note");
-    }
+    }/**
+     * 电话内容的数据结构
+     */
 }