padding
必须是可选的,所以如果我不传递任何填充参数,则需要为 0,但它不接受构造函数中的任何值,这与布尔bold
参数不同。
class QText extends StatelessWidget {
QText(this.text, this.size,
{this.align, this.bold = false, this.colour, this.font, this.padding});
final String text;
final double size;
final bool bold;
final Color colour;
final String font;
final TextAlign align;
final List<double> padding;
@override
Widget build(BuildContext context) {
return Padding(
padding: EdgeInsets.fromLTRB(padding[0], padding[1],
padding[2], padding[3]),
child: Text(
text,
textAlign: align,
style: TextStyle(
fontSize: size,
fontWeight: (bold) ? FontWeight.bold : FontWeight.normal,
fontFamily: (font != '') ? font : '',
color: colour,
),
),
);
}
}
我似乎无法将QText(this.text, this.size,
{this.align, this.bold = false, this.colour, this.font, this.padding = [0.0,0.0,0.0,0.0]]});
或类似的东西设置为工作,因为它会抛出错误Default values of an optional parameter must be constant.
,而且我也无法设置final List<double> padding ?? [0.0,0.0,0.0,0.0];
如果我不为它传递参数,我怎么能给它一个默认值?因为它毕竟应该是可选的,但Padding
小部件也不接受无填充。
你有没有尝试过:
QText(this.text, this.size, {this.align, this.bold = false, this.colour, this.font, this.padding = const <double>[0, 0, 0, 0]});