初步优化项目结构

lib/widget_system/widgets/StatefulWidget/SelectableText/node2_align.dart

@@ -0,0 +1,73 @@
+import 'package:flutter/material.dart';
+
+/// create by 张风捷特烈 on 2020-03-31
+/// contact me by email 1981462002@qq.com
+/// 说明:
+//    {
+//      "widgetId": 53,
+//      "name": 'SelectableText对齐属性',
+//      "priority": 2,
+//      "subtitle":
+//          "【textAlign】 : 对齐方式*6   【textAlign】\n"
+//          "【textDirection】 : 文字方向*2   【TextDirection】",
+//    }
+class AlignSelectableText extends StatefulWidget {
+  @override
+  _AlignSelectableTextState createState() => _AlignSelectableTextState();
+}
+
+class _AlignSelectableTextState extends State<AlignSelectableText> {
+  final String text =
+      "The [SelectableText] widget displays a string of text with a single style."
+      "The string might break across multiple lines or might all be displayed on"
+      "the same line depending on the layout constraints.";
+  TextAlign _textAlign = TextAlign.left;
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      children: <Widget>[
+        _buildSelector(),
+        SelectableText(
+          text,
+          style: TextStyle(fontSize: 18, color: Colors.red),
+          cursorColor: Colors.green,
+          cursorRadius: Radius.circular(3),
+          cursorWidth: 5,
+          showCursor: true,
+          textAlign: _textAlign,
+          textDirection: TextDirection.ltr,
+
+          autofocus: false,
+        ),
+      ],
+    );
+  }
+
+  Widget _buildSelector() {
+    return Row(
+      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
+      children: <Widget>[
+        Text(
+          "textAlign属性选择:",
+          style: TextStyle(
+              fontSize: 16, color: Colors.blue, fontWeight: FontWeight.bold),
+        ),
+        DropdownButton<TextAlign>(
+            underline: Container(),
+            value: _textAlign,
+            items: TextAlign.values
+                .map((e) => DropdownMenuItem<TextAlign>(
+                      value: e,
+                      child: Text(e.toString()),
+                    ))
+                .toList(),
+            onChanged: (e) {
+              setState(() {
+                _textAlign = e??_textAlign;
+              });
+            }),
+      ],
+    );
+  }
+}