Flutter 异常类型Future（void）不在Future的子类型中<；动画控制器>；
下面的代码在flatter中执行布局的创建，要创建布局，我必须首先确保执行set函数以使其使用future builder，但当我运行代码时，出现以下错误。 它告诉我存在以下错误，future不是future的子类型， 理论上两者都是从对象派生的，所以dart上不应该有继承问题，这是因为什么 错误：Flutter 异常类型Future（void）不在Future的子类型中<；动画控制器>；,flutter,future,futuretask,Flutter,Future,Futuretask,下面的代码在flatter中执行布局的创建，要创建布局，我必须首先确保执行set函数以使其使用future builder，但当我运行代码时，出现以下错误。 它告诉我存在以下错误，future不是future的子类型， 理论上两者都是从对象派生的，所以dart上不应该有继承问题，这是因为什么 错误： import ... double latitudine=0; Future<void> setValori() async { latitudine=await Gps.ge
import ...
double latitudine=0;
Future<void> setValori() async {
latitudine=await Gps.getLatitudine();
print("Latitudine: "+latitudine.toString());
print("\n \n Sono dentro set valori \n \n");
}
class MediterranesnDietView extends StatelessWidget {
final AnimationController animationController;
final Animation animation;
const MediterranesnDietView(
{Key key, this.animationController, this.animation})
: super(key: key);
@override
Widget build(BuildContext context) {
return FutureBuilder<AnimatedBuilder>(
future: setValori(),
builder: (BuildContext context, AsyncSnapshot<AnimatedBuilder> snapshot) {
return AnimatedBuilder(
animation: animationController,
builder: (BuildContext context, Widget child) {
return FadeTransition(
opacity: animation,
child: new Transform(
transform: new Matrix4.translationValues(
0.0, 30 * (1.0 - animation.value), 0.0),
child: Padding(
padding: const EdgeInsets.only(
left: 24, right: 24, top: 16, bottom: 18),
child: Container(
decoration: BoxDecoration(
color: FintnessAppTheme.white,
borderRadius: BorderRadius.only(
topLeft: Radius.circular(8.0),
bottomLeft: Radius.circular(8.0),
bottomRight: Radius.circular(8.0),
topRight: Radius.circular(68.0)),
boxShadow: <BoxShadow>[
BoxShadow(
color: FintnessAppTheme.grey.withOpacity(0.2),
offset: Offset(1.1, 1.1),
blurRadius: 10.0),
],
),
child: Column(
children: <Widget>[
Padding(
padding:
const EdgeInsets.only(top: 16, left: 16, right: 16),
child: Row(
children: <Widget>[
Expanded(
child: Padding(
padding: const EdgeInsets.only(
left: 8, right: 8, top: 4),
child: Column(
children: <Widget>[
Row(
children: <Widget>[
Container(
height: 48,
width: 2,
decoration: BoxDecoration(
color: HexColor('#87A0E5')
.withOpacity(0.5),
borderRadius: BorderRadius.all(
Radius.circular(4.0)),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: Column(
mainAxisAlignment:
MainAxisAlignment.center,
crossAxisAlignment:
CrossAxisAlignment.start,
children: <Widget>[
Padding(
padding: const EdgeInsets.only(
left: 4, bottom: 2),
child: Text(
'Latitudine',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme.fontName,
fontWeight: FontWeight.w500,
fontSize: 16,
letterSpacing: -0.1,
color: FintnessAppTheme.grey
.withOpacity(0.5),
),
),
),
Row(
mainAxisAlignment:
MainAxisAlignment.center,
crossAxisAlignment:
CrossAxisAlignment.end,
children: <Widget>[
SizedBox(
width: 28,
height: 28,
child: Image.asset(
"assets/Home/eaten.png"),
),
Padding(
padding:
const EdgeInsets.only(
left: 4, bottom: 3),
child: Text(
'${(latitudine * animation.value).toInt()}',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme
.fontName,
fontWeight:
FontWeight.w600,
fontSize: 16,
color: FintnessAppTheme
.darkerText,
),
),
),
Padding(
padding:
const EdgeInsets.only(
left: 4, bottom: 3),
child: Text(
'',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme
.fontName,
fontWeight:
FontWeight.w600,
fontSize: 12,
letterSpacing: -0.2,
color: FintnessAppTheme
.grey
.withOpacity(0.5),
),
),
),
],
)
],
),
)
],
),
SizedBox(
height: 8,
),
Row(
children: <Widget>[
Container(
height: 48,
width: 2,
decoration: BoxDecoration(
color: HexColor('#F56E98')
.withOpacity(0.5),
borderRadius: BorderRadius.all(
Radius.circular(4.0)),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: Column(
mainAxisAlignment:
MainAxisAlignment.center,
crossAxisAlignment:
CrossAxisAlignment.start,
children: <Widget>[
Padding(
padding: const EdgeInsets.only(
left: 4, bottom: 2),
child: Text(
'Longitudine',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme.fontName,
fontWeight: FontWeight.w500,
fontSize: 16,
letterSpacing: -0.1,
color: FintnessAppTheme.grey
.withOpacity(0.5),
),
),
),
Row(
mainAxisAlignment:
MainAxisAlignment.center,
crossAxisAlignment:
CrossAxisAlignment.end,
children: <Widget>[
SizedBox(
width: 28,
height: 28,
child: Image.asset(
"assets/Home/burned.png"),
),
Padding(
padding:
const EdgeInsets.only(
left: 4, bottom: 3),
child: Text(
'${(102 * animation.value).toInt()}',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme
.fontName,
fontWeight:
FontWeight.w600,
fontSize: 16,
color: FintnessAppTheme
.darkerText,
),
),
),
Padding(
padding:
const EdgeInsets.only(
left: 8, bottom: 3),
child: Text(
'Kcal',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme
.fontName,
fontWeight:
FontWeight.w600,
fontSize: 12,
letterSpacing: -0.2,
color: FintnessAppTheme
.grey
.withOpacity(0.5),
),
),
),
],
)
],
),
)
],
)
],
),
),
),
Padding(
padding: const EdgeInsets.only(right: 16),
child: Center(
child: Stack(
overflow: Overflow.visible,
children: <Widget>[
Padding(
padding: const EdgeInsets.all(8.0),
child: Container(
width: 100,
height: 100,
decoration: BoxDecoration(
color: FintnessAppTheme.white,
borderRadius: BorderRadius.all(
Radius.circular(100.0),
),
border: new Border.all(
width: 4,
color: FintnessAppTheme
.nearlyDarkBlue
.withOpacity(0.2)),
),
child: Column(
mainAxisAlignment:
MainAxisAlignment.center,
crossAxisAlignment:
CrossAxisAlignment.center,
children: <Widget>[
Text(
'${(1503 * animation.value).toInt()}',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme.fontName,
fontWeight: FontWeight.normal,
fontSize: 24,
letterSpacing: 0.0,
color: FintnessAppTheme
.nearlyDarkBlue,
),
),
Text(
'Kcal left',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme.fontName,
fontWeight: FontWeight.bold,
fontSize: 12,
letterSpacing: 0.0,
color: FintnessAppTheme.grey
.withOpacity(0.5),
),
),
],
),
),
),
Padding(
padding: const EdgeInsets.all(4.0),
child: CustomPaint(
painter: CurvePainter(
colors: [
FintnessAppTheme.nearlyDarkBlue,
HexColor("#8A98E8"),
HexColor("#8A98E8")
],
angle: 140 +
(360 - 140) *
(1.0 - animation.value)),
child: SizedBox(
width: 108,
height: 108,
),
),
)
],
),
),
)
],
),
),
Padding(
padding: const EdgeInsets.only(
left: 24, right: 24, top: 8, bottom: 8),
child: Container(
height: 2,
decoration: BoxDecoration(
color: FintnessAppTheme.background,
borderRadius: BorderRadius.all(Radius.circular(4.0)),
),
),
),
Padding(
padding: const EdgeInsets.only(
left: 24, right: 24, top: 8, bottom: 16),
child: Row(
children: <Widget>[
Expanded(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(
'Carbs',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily: FintnessAppTheme.fontName,
fontWeight: FontWeight.w500,
fontSize: 16,
letterSpacing: -0.2,
color: FintnessAppTheme.darkText,
),
),
Padding(
padding: const EdgeInsets.only(top: 4),
child: Container(
height: 4,
width: 70,
decoration: BoxDecoration(
color:
HexColor('#87A0E5').withOpacity(0.2),
borderRadius: BorderRadius.all(
Radius.circular(4.0)),
),
child: Row(
children: <Widget>[
Container(
width: ((70 / 1.2) * animation.value),
height: 4,
decoration: BoxDecoration(
gradient: LinearGradient(colors: [
HexColor('#87A0E5'),
HexColor('#87A0E5')
.withOpacity(0.5),
]),
borderRadius: BorderRadius.all(
Radius.circular(4.0)),
),
)
],
),
),
),
Padding(
padding: const EdgeInsets.only(top: 6),
child: Text(
'12g left',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily: FintnessAppTheme.fontName,
fontWeight: FontWeight.w600,
fontSize: 12,
color: FintnessAppTheme.grey
.withOpacity(0.5),
),
),
),
],
),
),
...
),
),
),
);
},
);
});
}
}
import ...
double latitudine=0;
Future<void> setValori() async {
latitudine=await Gps.getLatitudine();
print("Latitudine: "+latitudine.toString());
print("\n \n Sono dentro set valori \n \n");
}
class MediterranesnDietView extends StatelessWidget {
final AnimationController animationController;
final Animation animation;
const MediterranesnDietView(
{Key key, this.animationController, this.animation})
: super(key: key);
@override
Widget build(BuildContext context) {
return FutureBuilder<AnimatedBuilder>(
future: setValori(),
builder: (BuildContext context, AsyncSnapshot<AnimatedBuilder> snapshot) {
return AnimatedBuilder(
animation: animationController,
builder: (BuildContext context, Widget child) {
return FadeTransition(
opacity: animation,
child: new Transform(
transform: new Matrix4.translationValues(
0.0, 30 * (1.0 - animation.value), 0.0),
child: Padding(
padding: const EdgeInsets.only(
left: 24, right: 24, top: 16, bottom: 18),
child: Container(
decoration: BoxDecoration(
color: FintnessAppTheme.white,
borderRadius: BorderRadius.only(
topLeft: Radius.circular(8.0),
bottomLeft: Radius.circular(8.0),
bottomRight: Radius.circular(8.0),
topRight: Radius.circular(68.0)),
boxShadow: <BoxShadow>[
BoxShadow(
color: FintnessAppTheme.grey.withOpacity(0.2),
offset: Offset(1.1, 1.1),
blurRadius: 10.0),
],
),
child: Column(
children: <Widget>[
Padding(
padding:
const EdgeInsets.only(top: 16, left: 16, right: 16),
child: Row(
children: <Widget>[
Expanded(
child: Padding(
padding: const EdgeInsets.only(
left: 8, right: 8, top: 4),
child: Column(
children: <Widget>[
Row(
children: <Widget>[
Container(
height: 48,
width: 2,
decoration: BoxDecoration(
color: HexColor('#87A0E5')
.withOpacity(0.5),
borderRadius: BorderRadius.all(
Radius.circular(4.0)),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: Column(
mainAxisAlignment:
MainAxisAlignment.center,
crossAxisAlignment:
CrossAxisAlignment.start,
children: <Widget>[
Padding(
padding: const EdgeInsets.only(
left: 4, bottom: 2),
child: Text(
'Latitudine',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme.fontName,
fontWeight: FontWeight.w500,
fontSize: 16,
letterSpacing: -0.1,
color: FintnessAppTheme.grey
.withOpacity(0.5),
),
),
),
Row(
mainAxisAlignment:
MainAxisAlignment.center,
crossAxisAlignment:
CrossAxisAlignment.end,
children: <Widget>[
SizedBox(
width: 28,
height: 28,
child: Image.asset(
"assets/Home/eaten.png"),
),
Padding(
padding:
const EdgeInsets.only(
left: 4, bottom: 3),
child: Text(
'${(latitudine * animation.value).toInt()}',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme
.fontName,
fontWeight:
FontWeight.w600,
fontSize: 16,
color: FintnessAppTheme
.darkerText,
),
),
),
Padding(
padding:
const EdgeInsets.only(
left: 4, bottom: 3),
child: Text(
'',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme
.fontName,
fontWeight:
FontWeight.w600,
fontSize: 12,
letterSpacing: -0.2,
color: FintnessAppTheme
.grey
.withOpacity(0.5),
),
),
),
],
)
],
),
)
],
),
SizedBox(
height: 8,
),
Row(
children: <Widget>[
Container(
height: 48,
width: 2,
decoration: BoxDecoration(
color: HexColor('#F56E98')
.withOpacity(0.5),
borderRadius: BorderRadius.all(
Radius.circular(4.0)),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: Column(
mainAxisAlignment:
MainAxisAlignment.center,
crossAxisAlignment:
CrossAxisAlignment.start,
children: <Widget>[
Padding(
padding: const EdgeInsets.only(
left: 4, bottom: 2),
child: Text(
'Longitudine',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme.fontName,
fontWeight: FontWeight.w500,
fontSize: 16,
letterSpacing: -0.1,
color: FintnessAppTheme.grey
.withOpacity(0.5),
),
),
),
Row(
mainAxisAlignment:
MainAxisAlignment.center,
crossAxisAlignment:
CrossAxisAlignment.end,
children: <Widget>[
SizedBox(
width: 28,
height: 28,
child: Image.asset(
"assets/Home/burned.png"),
),
Padding(
padding:
const EdgeInsets.only(
left: 4, bottom: 3),
child: Text(
'${(102 * animation.value).toInt()}',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme
.fontName,
fontWeight:
FontWeight.w600,
fontSize: 16,
color: FintnessAppTheme
.darkerText,
),
),
),
Padding(
padding:
const EdgeInsets.only(
left: 8, bottom: 3),
child: Text(
'Kcal',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme
.fontName,
fontWeight:
FontWeight.w600,
fontSize: 12,
letterSpacing: -0.2,
color: FintnessAppTheme
.grey
.withOpacity(0.5),
),
),
),
],
)
],
),
)
],
)
],
),
),
),
Padding(
padding: const EdgeInsets.only(right: 16),
child: Center(
child: Stack(
overflow: Overflow.visible,
children: <Widget>[
Padding(
padding: const EdgeInsets.all(8.0),
child: Container(
width: 100,
height: 100,
decoration: BoxDecoration(
color: FintnessAppTheme.white,
borderRadius: BorderRadius.all(
Radius.circular(100.0),
),
border: new Border.all(
width: 4,
color: FintnessAppTheme
.nearlyDarkBlue
.withOpacity(0.2)),
),
child: Column(
mainAxisAlignment:
MainAxisAlignment.center,
crossAxisAlignment:
CrossAxisAlignment.center,
children: <Widget>[
Text(
'${(1503 * animation.value).toInt()}',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme.fontName,
fontWeight: FontWeight.normal,
fontSize: 24,
letterSpacing: 0.0,
color: FintnessAppTheme
.nearlyDarkBlue,
),
),
Text(
'Kcal left',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme.fontName,
fontWeight: FontWeight.bold,
fontSize: 12,
letterSpacing: 0.0,
color: FintnessAppTheme.grey
.withOpacity(0.5),
),
),
],
),
),
),
Padding(
padding: const EdgeInsets.all(4.0),
child: CustomPaint(
painter: CurvePainter(
colors: [
FintnessAppTheme.nearlyDarkBlue,
HexColor("#8A98E8"),
HexColor("#8A98E8")
],
angle: 140 +
(360 - 140) *
(1.0 - animation.value)),
child: SizedBox(
width: 108,
height: 108,
),
),
)
],
),
),
)
],
),
),
Padding(
padding: const EdgeInsets.only(
left: 24, right: 24, top: 8, bottom: 8),
child: Container(
height: 2,
decoration: BoxDecoration(
color: FintnessAppTheme.background,
borderRadius: BorderRadius.all(Radius.circular(4.0)),
),
),
),
Padding(
padding: const EdgeInsets.only(
left: 24, right: 24, top: 8, bottom: 16),
child: Row(
children: <Widget>[
Expanded(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(
'Carbs',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily: FintnessAppTheme.fontName,
fontWeight: FontWeight.w500,
fontSize: 16,
letterSpacing: -0.2,
color: FintnessAppTheme.darkText,
),
),
Padding(
padding: const EdgeInsets.only(top: 4),
child: Container(
height: 4,
width: 70,
decoration: BoxDecoration(
color:
HexColor('#87A0E5').withOpacity(0.2),
borderRadius: BorderRadius.all(
Radius.circular(4.0)),
),
child: Row(
children: <Widget>[
Container(
width: ((70 / 1.2) * animation.value),
height: 4,
decoration: BoxDecoration(
gradient: LinearGradient(colors: [
HexColor('#87A0E5'),
HexColor('#87A0E5')
.withOpacity(0.5),
]),
borderRadius: BorderRadius.all(
Radius.circular(4.0)),
),
)
],
),
),
),
Padding(
padding: const EdgeInsets.only(top: 6),
child: Text(
'12g left',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily: FintnessAppTheme.fontName,
fontWeight: FontWeight.w600,
fontSize: 12,
color: FintnessAppTheme.grey
.withOpacity(0.5),
),
),
),
],
),
),
...
),
),
),
);
},
);
});
}
}
导入。。。
双纬度=0；
Future setValori（）异步{
latitudine=等待Gps.getLatitudine（）；
打印（“Latitudine:+Latitudine.toString（））；
打印（“\n\n Sono dentro set valori\n\n”）；
}
类MediterransNDietView扩展了无状态小部件{
最终AnimationController AnimationController；
最终动画；
康斯特地中海酒店(
{Key Key，this.animationController，this.animation}）
：super（key:key）；
@凌驾
小部件构建（构建上下文）{
回归未来建设者(
future:setValori（），
生成器：（BuildContext上下文，异步快照）{
返回动画生成器(
动画：animationController，
生成器：（BuildContext上下文，小部件子项）{
返回衰减转换(
不透明度：动画，
孩子：新的转变(
转换：新矩阵4.translationValues(
0.0,30*（1.0-动画值），0.0），
孩子：填充(
填充：仅限常量边设置(
左：24，右：24，顶部：16，底部：18），
子：容器(
装饰：盒子装饰(
颜色：FintnessAppTheme.white，
borderRadius：仅限borderRadius(
左上：半径。圆形（8.0），
左下角：半径。圆形（8.0），
右下角：半径。圆形（8.0），
右上角：半径。圆形（68.0）），
boxShadow：[
箱形阴影(
颜色：FintMessageAppTheme.灰色，不透明度（0.2），
偏移量：偏移量（1.1,1.1），
半径：10.0），
],
),
子：列(
儿童：[
填充物(
衬垫：
仅限常数边集（顶部：16，左侧：16，右侧：16），
孩子：排(
儿童：[
扩大(
孩子：填充(
填充：仅限常量边设置(
左：8，右：8，顶：4），
子：列(
儿童：[
划船(
儿童：[
容器(
身高：48，
宽度：2，
装饰：盒子装饰(
颜色：HexColor（“#87A0E5”）
.不透明度（0.5），
borderRadius:borderRadius.all(
圆半径（4.0）），
),
),
填充物(
填充：常数边集全部（8.0），
子：列(
主轴对准：
main.center，
横轴对齐：
CrossAxisAlignment.start，
儿童：[
填充物(
填充：仅限常量边设置(
左：4，下：2），
子：文本(
“Latitudine”，
textAlign:textAlign.center，
样式：TextStyle(
fontFamily：
FintnessAppTheme.fontName，
fontWeight:fontWeight.w500，
尺寸：16，
字母间距：-0.1，
颜色：FintnessAppTheme.grey
.不透明度（0.5），
),
),
),
划船(
主轴对准：
main.center，
横轴对齐：
CrossAxisAlignment.end，
儿童：[
大小盒子(
宽度：28，
身高：28，
子：Image.asset(
“assets/Home/eat.png”），
),
return FutureBuilder<void>