我遇到了一个非常奇怪的问题。这就像某种类型的混淆?
如果我这样写我的动画,它会按预期工作:
Widget _animatedButtonsBuilder(BuildContext context, LoginState state) {
final animTarget = state.isPhoneNumberFocused
? _controller.lowerBound
: _controller.upperBound;
_controller.animateTo(animTarget);
final double width = MediaQuery.of(context).size.width;
//final transform = Matrix4.translationValues(_animation.value * width, 0.0, 0.0)..scale(1.0, 1.0-_animation.value, 1.0);
return AnimatedBuilder(
animation: _controller,
builder: (BuildContext context, Widget child) {
return Transform(
transform: Matrix4.translationValues(_animation.value * width, 0.0, 0.0)..scale(1.0, 1.0-_animation.value, 1.0),
child: new RaisedButton(
child: const Text('Login'),
color: Color(0xff938065),
elevation: 4.0,
splashColor: Colors.blueGrey,
textColor: Color(0xffffffff),
onPressed: () {},
));
});
}
但是如果我取消注释
//final transform = Matrix4.transla...
并将其传递给 transform:
参数,它似乎无法正常工作。
这是怎么回事?
最佳答案
我认为要获得相同的结果,您需要将该行移至生成器中, 因为它会在每次动画进行时执行,而不仅仅是在动画开始时执行。
Widget _animatedButtonsBuilder(BuildContext context, LoginState state) {
final animTarget = state.isPhoneNumberFocused
? _controller.lowerBound
: _controller.upperBound;
_controller.animateTo(animTarget);
final double width = MediaQuery.of(context).size.width;
return AnimatedBuilder(
animation: _controller,
builder: (BuildContext context, Widget child) {
//final transform = Matrix4.translationValues(_animation.value * width, 0.0, 0.0)..scale(1.0, 1.0-_animation.value, 1.0);
return Transform(
transform: Matrix4.translationValues(_animation.value * width, 0.0, 0.0)..scale(1.0, 1.0-_animation.value, 1.0),
child: new RaisedButton(
child: const Text('Login'),
color: Color(0xff938065),
elevation: 4.0,
splashColor: Colors.blueGrey,
textColor: Color(0xffffffff),
onPressed: () {},
));
});
}
关于dart - Matrix4 参数在间接传递给 Transform 时表现不同,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/54996791/