Flutter基础widgets教程-Transform篇

1 Transform

在绘制子widget之前应用转换的widget

2 构造函数

Transform({
    Key key,
    @required this.transform,
    this.origin,
    this.alignment,
    this.transformHitTests = true,
    Widget child,
})

3 常用属性

3.1 origin：指定子组件做平移、旋转、缩放时的中心点

origin: Offset(50, 50),

3.2 alignment：对齐方式

alignment:Alignment.center,

3.2.1 顶部左边

alignment:Alignment.topLeft,

3.2.2 顶部中间

alignment:Alignment.topCenter,

3.2.3 顶部右边

alignment:Alignment.topRight,

3.2.4 中部左边

alignment:Alignment.centerLeft,

3.2.5 中部中间

alignment:Alignment.center,

3.2.6 中部右边

alignment:Alignment.centerRight,

3.2.7 底部左边

alignment:Alignment.bottomLeft,

3.2.8 底部中间

alignment:Alignment.bottomCenter,

3.2.9 底部右边

alignment:Alignment.bottomRight,

3.3 transformHitTests：点击区域是否也做相应的变换,为true时执行相应的变换,为false不执行

transformHitTests:true,

3.4 transform：控制子组件的平移、旋转、缩放、倾斜变换

transform: Matrix4.rotationX(radian),

3.4.1 旋转

transform: Matrix4.rotationX(radian),
transform: Matrix4.rotationY(radian),
transform: Matrix4.rotationZ(radian),

3.4.2 平移

transform:Matrix4.translation(Vector3(x, y, z)),
transform:Matrix4.translation(Vector3.all(val)),
transform:Matrix4.translationValues(x, y, z),

3.4.3 缩放

transform:Matrix4.diagonal3(Vector3(x, y, z)),
transform:Matrix4.diagonal3(Vector3.all(val)),
transform:Matrix4.diagonal3Values(x, y, z),

3.4.4 倾斜

transform:Matrix4.skewX(alpha),
transform:Matrix4.skewY(double beta),
transform:Matrix4.skew(alpha, beta),

3.5 child：子widget

child: Text('你好 Flutter'),

4.显示效果

5.代码

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_markdown/flutter_markdown.dart';
// 字体适配
import '../../utils/app_size.dart';

class ListTransform extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return DefaultTabController(
      length: 2,
      child: Scaffold(
        appBar: AppBar(
          title: Text('Transform'),
          backgroundColor: Color(0xFFfafcff),
          bottom: TabBar(labelColor: Color(0xff030303), tabs: [
            Tab(
              text: "效果",
            ),
            Tab(
              text: "属性",
            )
          ]),
        ),
        body: TabBarView(children: [
          Container(
              decoration: new BoxDecoration(
                color: new Color(0xffffffff),
                borderRadius: new BorderRadius.circular((AppSize.width(20))),
              ),
              child: ShowEffect()),
          Container(
              decoration: new BoxDecoration(
                color: new Color(0xffffffff),
                borderRadius: new BorderRadius.circular((AppSize.width(20))),
              ),
              child: ShowAttribute()),
        ]),
      ),
    );
  }
}

// 效果
class ShowEffect extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text("Transform"),
        ),
        body: Center(
          child: Container(
            color: Colors.black,
            child: new Transform(
              alignment: Alignment.topRight, //相对于坐标系原点的对齐方式
              transform: new Matrix4.skewY(0.3), //沿Y轴倾斜0.3弧度
              child: new Container(
                padding: const EdgeInsets.all(8.0),
                color: Colors.deepOrange,
                child: const Text('转换的widget'),
              ),
            ),
          ),
        ),
      ),
    );
  }
}

// 属性
class ShowAttribute extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
      child: FutureBuilder(
        future: rootBundle.loadString('lib/markdown/transform.md'),
        builder: (BuildContext context, AsyncSnapshot snapshot) {
          if (snapshot.hasData) {
            return Markdown(
              data: snapshot.data,
              selectable: true,
            );
          } else {
            return Center(
              child: Text("加载中..."),
            );
          }
        },
      ),
    );
  }
}

此代码已共享到码云，已对60多种widget做演示及解释。一直更新中

https://gitee.com/nmgwap/flutter_app

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