[英]Change Background Color of Elevated Button OnPressed in Flutter
[英]why radio button don't change color onPressed - Flutter?
我的底部模式表中有 2 個自定義單選按鈕。 當我點擊onPressed
方法時,它們不會立即改變顏色。 在我關閉並再次打開模式菜單后,顏色設置正確。
Widget customRadio(String text, int index){
return OutlinedButton(
onPressed: () {
setState((){
selected = index;
});
},
child: Text(
text, style: TextStyle(color: (selected == index) ?Colors.white: Colors.grey),
),
style: OutlinedButton.styleFrom(
primary: Colors.white,
backgroundColor: (selected == index)?Colors.deepOrange: Colors.white,
),
);
}
為小部件BottomSheet
創建新的statefulWidget
,添加int selected = 0;
移至DialogStatefull
試試這個演示;
import 'package:flutter/material.dart';
class SaveScreen extends StatefulWidget {
const SaveScreen({Key? key}) : super(key: key);
@override
State<SaveScreen> createState() => _SaveScreenState();
}
class _SaveScreenState extends State<SaveScreen> {
@override
Widget build(BuildContext context) {
return Center(
child: ElevatedButton(
child: const Text('showModalBottomSheet'),
onPressed: () {
showModalBottomSheet<void>(
context: context,
builder: (BuildContext context) {
return DialogStatefull();
},
);
},
),
);
}
}
class DialogStatefull extends StatefulWidget {
const DialogStatefull({Key? key}) : super(key: key);
@override
State<DialogStatefull> createState() => _DialogStatefullState();
}
class _DialogStatefullState extends State<DialogStatefull> {
int selected = 0;
@override
Widget build(BuildContext context) {
return StatefulBuilder(builder: (context, state) {
return Container(
height: 200,
color: Colors.amber,
child: Center(
child: Column(
children: [
customRadio("helo", 0),
customRadio("helo", 1),
customRadio("helo", 2),
],
),
),
);
});
}
Widget customRadio(String text, int index) {
return OutlinedButton(
onPressed: () {
setState(() {
selected = index;
print(index);
print(selected);
});
},
child: Text(
text,
style:
TextStyle(color: (selected == index) ? Colors.white : Colors.grey),
),
style: OutlinedButton.styleFrom(
primary: Colors.white,
backgroundColor: (selected == index) ? Colors.deepOrange : Colors.white,
),
);
}
}
如果您想在同一屏幕上顯示底頁,則需要將 StatefulBuilder 與 StateSetter 參數一起使用
int selected = 0;
Widget customRadio(
{required String text, required int index, Function()? onTap,
}) {
return OutlinedButton(
onPressed: onTap,
style: OutlinedButton.styleFrom(
primary: Colors.white,
backgroundColor: (selected == index) ? Colors.deepOrange : Colors.white,
),
child: Text(
text,
style:
TextStyle(color: (selected == index) ? Colors.white : Colors.grey),
),
);
}
將函數作為參數傳遞給您需要更改 ui 的小部件
_showBottomSheet() {
return showModalBottomSheet(
context: context,
builder: (context) {
return StatefulBuilder(
builder: (BuildContext context, StateSetter setState) {
return Column(
children: [
customRadio(
text: 'button1',
index: 1,
onTap: () {
setState(() {
selected = 1;
});
},
),
customRadio(
text: 'button2',
index: 2,
onTap: () {
setState(() {
selected = 2;
});
},
),
],
);
});
},
);
}
這是帶有小部件列表的底頁
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