flutter - Flutter OutlinedButton 小部件中奇怪的黑色背景

Question

我正在使用 Flutter 的 OutlineButton 小部件，但我不知道如何在单击/按下按钮时删除那个奇怪的黑色背景突出显示。

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这是按钮:

OutlineButton(
  highlightElevation: 1.0,
  onPressed: () => onRequestAllowLocation(context),
  child: Text(
    "ALLOW LOCATION",
    style: TextStyle(fontWeight: FontWeight.w600, fontSize: 16),
  ),
  borderSide: BorderSide(color: MyApp.accentColor, width: 2.0),
  textColor: MyApp.accentColor,
  shape: new RoundedRectangleBorder(borderRadius: new BorderRadius.circular(16.0))),
)

这是应用程序的主题:

ThemeData(
  fontFamily: 'Dosis',
  brightness: Brightness.dark,
  primarySwatch: Colors.blue,
  accentColor: accentColor,
  highlightColor: highlightColor,
  buttonColor: accentColor,
  indicatorColor: accentColor,
  backgroundColor: primaryColor,
  scaffoldBackgroundColor: primaryColor,
  primaryColor: primaryColor,
)

附言我在上面提供的 const 颜色都不是黑色。

Answer 1

是影子。停止设置 highlightElevation，它就会消失。来自 OutlineButton class docs :

The button's highlightElevation, which defines the size of the drop shadow when the button is pressed, is 0.0 (no shadow) by default. If highlightElevation is given a value greater than 0.0 then the button becomes a cross between RaisedButton and FlatButton: a bordered button whose elevation increases and whose background becomes opaque when the button is pressed.