修复DatePicker绑定 - DateTime改为DateTime?可空类型

src/YZWater.Core/ViewModels/ViewCViewModel.cs

@@ -29,10 +29,10 @@ public partial class ViewCViewModel : ObservableObject
     private Axis[] _yAxes;
 
     [ObservableProperty]
-    private DateTime _startDate = DateTime.Now.AddDays(-7);
+    private DateTime? _startDate = DateTime.Now.AddDays(-7);
 
     [ObservableProperty]
-    private DateTime _endDate = DateTime.Now;
+    private DateTime? _endDate = DateTime.Now;
 
     [ObservableProperty]
     private List<FlowRecord> _flowRecords = new();
@@ -98,8 +98,10 @@ public partial class ViewCViewModel : ObservableObject
     {
         try
         {
+            var start = StartDate ?? DateTime.Now.AddDays(-7);
+            var end = EndDate ?? DateTime.Now;
             var records = await DatabaseService.Db.Select<FlowRecord>()
-                .Where(r => r.RecordTime >= StartDate && r.RecordTime <= EndDate)
+                .Where(r => r.RecordTime >= start && r.RecordTime <= end)
                 .OrderByDescending(r => r.RecordTime)
                 .ToListAsync();
 

src/YZWater.Core/ViewModels/ViewDViewModel.cs

@@ -21,10 +21,10 @@ public partial class ViewDViewModel : ObservableObject
     private int _unconfirmedCount;
 
     [ObservableProperty]
-    private DateTime _startDate = DateTime.Now.AddDays(-7);
+    private DateTime? _startDate = DateTime.Now.AddDays(-7);
 
     [ObservableProperty]
-    private DateTime _endDate = DateTime.Now;
+    private DateTime? _endDate = DateTime.Now;
 
     [ObservableProperty]
     private string _filterType = "全部";
@@ -42,8 +42,10 @@ public partial class ViewDViewModel : ObservableObject
     {
         try
         {
+            var start = StartDate ?? DateTime.Now.AddDays(-7);
+            var end = EndDate ?? DateTime.Now;
             var query = DatabaseService.Db.Select<AlarmRecord>()
-                .Where(r => r.AlarmTime >= StartDate && r.AlarmTime <= EndDate);
+                .Where(r => r.AlarmTime >= start && r.AlarmTime <= end);
 
             if (FilterType != "全部")
             {