TextEditingController

  //文本编辑控制器
  TextEditingController controller = TextEditingController();

  //提交数据
  void commit(){
    if(controller.text.length == 0){
      showDialog(context: context,builder: (context) => AlertDialog(title: Text('请输入内容'),),);
    } else{
      var info = contactCompany(controller.text);
      print(info);
    }
  }
  
  
  
  //组件
  SizedBox(
              width: 380.0,
              child: TextField(
                controller: controller,
                decoration: InputDecoration(
                  hintText: '请留言',
                  labelText: '请留言',
                  border: OutlineInputBorder(),
                  prefixIcon: Icon(Icons.person),
                ),
              ),
            ),
            
            
  //按钮
  SizedBox(
              width: 220.0,
              height: 48.0,
              child: RaisedButton(
                child: Text('给我们留言',style: TextStyle(fontSize: 16.0),),
                color: Theme.of(context).primaryColor,//Colors.redAccent,
                colorBrightness: Brightness.dark,
                textColor: Colors.white,
                padding: EdgeInsets.only(
                  left: 20.0,
                  right: 20.0,
                  top: 5.0,
                  bottom: 5.0,
                ),
                shape: RoundedRectangleBorder(
                  side: BorderSide(
                    width: 1.0,
                    color: Colors.white,
                    style: BorderStyle.solid,
                  ),
                  borderRadius: BorderRadius.only(
                    topRight: Radius.circular(4.0),
                    topLeft: Radius.circular(4.0),
                    bottomLeft: Radius.circular(4.0),
                    bottomRight: Radius.circular(4.0),
                  ),
                ),
                onPressed: (){
                  commit();
                },

              ),