问题

我尝试在按下时更改IconButton的图标形状和颜色，但没有任何反应。以下是我的代码：

String adTitle = widget.documentSnapshot['Title'];
String $adDescription = widget.documentSnapshot['Description'];

IconData _iconData = Icons.favorite_border_outlined;
Color _iconColor = Colors.red;

return Scaffold(
  body: Column(
    children: [ 
      Row(
        children: [
          IconButton(
            icon: Icon(
              _iconData,
              size: 40,
              color: _iconColor,
            ),
            onPressed: () {
              setState(() {
                _iconData = Icons.favorite;
                _iconColor = Colors.blue;
              });
            },
          )
        ],
      ),
    ],
  ),
);

 String adTitle = widget.documentSnapshot['Title'];
String $adDescription = widget.documentSnapshot['Description'];

IconData _iconData = Icons.favorite_border_outlined;
Color _iconColor = Colors.red;

return Scaffold(
  body: Column(
    children: [ 
      Row(
        children: [
          IconButton.outlined(
            icon: Icon(
              _iconData,
              size: 40,
              color: _iconColor,
            ),
            onPressed: () {
              setState(() {
                _iconData = Icons.favorite;
                _iconColor = Colors.blue;
              });
            },
          )
        ],
      ),
    ],
  ),
);
}

答案1

得分: 2

IconData _iconData = Icons.favorite_border_outlined;
Color _iconColor = Colors.red;

它们目前是局部变量。要使其正常工作，您需要将它们定义为类级别的变量（在build方法之外定义它们）。

<details>
<summary>英文:</summary>

IconData _iconData = Icons.favorite_border_outlined;
Color _iconColor = Colors.red;

They are local variables as of now. You need to make them class level varibales for this to work (define them outside build method)

</details>