modify some description

lib/widgets/elements/Frame/Box/ConstrainedBox/demo.dart

@@ -8,12 +8,17 @@ import 'package:flutter/widgets.dart';
  * LastUpdateTime: 2018/11/22
  * LastUpdateBy: xj.deng
  *
- * Describle:Align描述
+ * Describle:ConstrainedBox描述
  */
-class ConstracubedBox extends StatelessWidget {
+class ConstrainedBoxCreate extends StatelessWidget {
+  final double currWidth;
+  final String describe;
+
+  const ConstrainedBoxCreate({Key key,this.currWidth,this.describe}):
+        super(key: key);
+
   @override
   Widget build(BuildContext context) {
-    
     return Column(
       children: <Widget>[
         ConstrainedBox(
@@ -21,20 +26,22 @@ class ConstracubedBox extends StatelessWidget {
           constraints: const BoxConstraints(
             minWidth: 100.0,
             minHeight: 20.0,
-            maxWidth: 500.0,
+            maxWidth: 300.0,
             maxHeight: 50.0,
           ),
           child: new Container(
             margin: const EdgeInsets.only(left: 20.0, right: 20.0),
             //child 宽高超过制定限制范围失效，效果宽/高=100/20区域
-            width: 600.0,
+            width: currWidth,
             height: 250.0,
-            child: new Text('ConstrainedBox',style: TextStyle(color: Colors.white),),
-            color: Colors.red,
+            child: new Text(
+              describe,
+              style: TextStyle(color: Colors.white),
+            ),
+            color: Color(0xfff8bbd0),
           ),
         ),
-       
       ],
     );
   }
-}
+}

lib/widgets/elements/Frame/Box/ConstrainedBox/index.dart

@@ -17,7 +17,11 @@ const String _Text = '''
 const String _Text1 = '''
 ### **基本用法**
 > 添加额外的限制条件到child上
-- 比如说，你限制child最小高度为50.0像素，就可以用constraints: const BoxConstraints(minHeight：50）
+- ex:添加ConstrainedBox约束如下，传入不同Width约束的Container效果
+minWidth: 100.0,
+minHeight: 20.0,
+maxWidth: 300.0,
+maxHeight: 50.0
 
 ''';
 
@@ -36,7 +40,27 @@ class _DemoState extends State<Demo> {
       contentList: [
         _Text,
         _Text1,
-        ConstracubedBox(),
+        // maxWidth: 300.0,
+        ConstrainedBoxCreate(currWidth: 500, describe: "currWidth>maxWidth"),
+        SizedBox(
+          height: 10.0,
+        ),
+        ConstrainedBoxCreate(currWidth: 300, describe: "currWidth=maxWidth"),
+        SizedBox(
+          height: 10.0,
+        ),
+        ConstrainedBoxCreate(currWidth: 200, describe: "currWidth<maxWidth"),
+        SizedBox(
+          height: 10.0,
+        ),
+
+        // minWidth: 100.0,
+        ConstrainedBoxCreate(currWidth: 150, describe: "currWidth>minWidth"),
+        SizedBox(
+          height: 10.0,
+        ),
+        ConstrainedBoxCreate(currWidth: 100, describe: "currWidth=minWidth"),
+
       ],
       docUrl:
           'https://docs.flutter.io/flutter/widgets/ConstrainedBox-class.html',