新增倒计时

lib/widgets/countdown_time_text.dart

@@ -0,0 +1,91 @@
+import 'dart:async';
+
+import 'package:fluent_ui/fluent_ui.dart';
+
+class CountdownTimeText extends StatefulWidget {
+  final DateTime targetTime;
+
+  const CountdownTimeText({super.key, required this.targetTime});
+
+  @override
+  State<CountdownTimeText> createState() => _CountdownTimeTextState();
+}
+
+class _CountdownTimeTextState extends State<CountdownTimeText> {
+  Timer? _timer;
+
+  Widget? textWidget;
+
+  bool stopTimer = false;
+
+  @override
+  initState() {
+    _onUpdateTime(null);
+    if (!stopTimer) {
+      _timer = Timer.periodic(const Duration(seconds: 1), _onUpdateTime);
+    }
+    super.initState();
+  }
+
+  @override
+  dispose() {
+    _timer?.cancel();
+    _timer = null;
+    super.dispose();
+  }
+
+  _onUpdateTime(_) {
+    final now = DateTime.now();
+    final dur = widget.targetTime.difference(now);
+    setState(() {
+      textWidget = _chineseTimeText(dur);
+    });
+    // 时间到，停止计时，并向宿主传递超时信息
+    if (dur.inMilliseconds <= 0) {
+      stopTimer = true;
+      setState(() {});
+    }
+    if (stopTimer) {
+      _timer?.cancel();
+      _timer = null;
+    }
+  }
+
+  Widget _chineseTimeText(Duration duration) {
+    final surplus = duration;
+    int day = (surplus.inSeconds ~/ 3600) ~/ 24;
+    int hour = (surplus.inSeconds ~/ 3600) % 24;
+    int minute = surplus.inSeconds % 3600 ~/ 60;
+    int second = surplus.inSeconds % 60;
+    return Row(
+      mainAxisSize: MainAxisSize.min,
+      children: [
+        Text(
+          "$day天  ",
+          style: TextStyle(
+              fontSize: 24, color: day < 30 ? Colors.red : Colors.white),
+        ),
+        Text("${timePart(hour)}:${timePart(minute)}:${timePart(second)}"),
+      ],
+    );
+  }
+
+  String timePart(int p) {
+    if (p.toString().length == 1) return "0$p";
+    return "$p";
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    if (stopTimer) {
+      return const Text(
+        "正在进行中",
+        style: TextStyle(
+            fontSize: 18,
+            color: Color.fromRGBO(32, 220, 89, 1.0),
+            fontWeight: FontWeight.bold),
+      );
+    }
+    return textWidget ?? const Text("");
+  }
+}