Store.Management/Source/Store.Management/Views/Dialogs/UserBillingDialog.xaml.cs

using Store.Management.Framework.ViewModels;
using Prism.Commands;
using Prism.Services.Dialogs;
using Store.Management.Api.Transport;
using Store.Management.Api.Users;
using Store.Management.Framework.Controls;
using Store.Management.Framework.Services;
using NumericUpDown = HandyControl.Controls.NumericUpDown;
using System.Globalization;
using System.Windows.Controls;
using System.Windows.Input;

namespace Store.Management.Views.Dialogs;

public partial class UserBillingDialog : UserControl
{
    public UserBillingDialog() => InitializeComponent();

    private void OnAmountValueChanged(object sender, HandyControl.Data.FunctionEventArgs<double> e)
    {
        if (sender is NumericUpDown { IsKeyboardFocusWithin: true, DataContext: UserBillingDialogViewModel.BillingField field })
        {
            field.Value = (decimal)e.Info;
        }
    }

    private void OnAmountTextChanged(object sender, TextChangedEventArgs e)
    {
        // 显式输入与控件初始值相同的金额时，Value 不会触发变化。
        if (sender is NumericUpDown { IsKeyboardFocusWithin: true, DataContext: UserBillingDialogViewModel.BillingField field }
            && e.OriginalSource is TextBox input
            && decimal.TryParse(input.Text, NumberStyles.Number, CultureInfo.CurrentCulture, out decimal amount)
            && amount == field.Value)
        {
            field.Value = amount;
        }
    }
}

public sealed class UserBillingDialogViewModel(IUserService userService) : ConfirmDialogViewModel<UserItemViewModel>
{
    public sealed class BillingField(string label, decimal? original, decimal minimum,
        Action<UserBillingUpdateRequest, decimal> apply, bool integer = false)
    {
        private readonly decimal? originalValue = original;
        public string Label { get; } = label;
        public decimal? EnteredValue { get; private set; } = original;
        public decimal Value
        {
            get => EnteredValue ?? minimum;
            set => EnteredValue = value;
        }
        public decimal Minimum => Math.Min(originalValue ?? minimum, minimum);
        public decimal Maximum => Math.Max(originalValue ?? minimum, integer ? int.MaxValue : 999999m);
        public int DecimalPlaces => integer ? 0 : 2;
        public decimal Increment => integer ? 1m : 0.01m;
		
		internal bool ApplyChange(UserBillingUpdateRequest request)
        {
            if (EnteredValue is not decimal value || value == originalValue)
            {
                return false;
            }
            decimal maximum = integer ? int.MaxValue : 999999m;
            if (value < minimum || value > maximum || decimal.Round(value, DecimalPlaces) != value)
            {
                throw new FormatException($"{Label}范围为 {minimum} 至 {maximum}" + (integer ? "，请输入整数。" : "，最多两位小数。"));
            }
            apply(request, value);
            return true;
        }
    }

    public BillingField[] Fields { get; private set => SetProperty(ref field, value); } = [];

	public override void OnDialogOpened(IDialogParameters parameters)
    {
        base.OnDialogOpened(parameters);
        Title = $"计费配置 · {Parameter.UserName}";
        Fields =
        [
            new("店铺每月续费积分（积分/月）", Parameter.ShopPointsPerMonth, 30m, (request, value) => request.ShopPointsPerMonth = (int)value, integer: true),
            new("中转仓快递费（元/单）", Parameter.PostagePerOrder, 2.20m, (request, value) => request.PostagePerOrder = value),
            new("中转仓退货快递费（元/单）", Parameter.RefundPostagePerOrder, 2.50m, (request, value) => request.RefundPostagePerOrder = value),
            new("礼物单附加费（元/单）", Parameter.GiftOemAmountPerOrder, 0m, (request, value) => request.GiftOemAmountPerOrder = value),
            new("物流同步费（元/单）", Parameter.SyncLogisticsPerOrder, 0m, (request, value) => request.SyncLogisticsPerOrder = value)
        ];
    }

    public override bool CanCloseDialog() => !IsLoading;
    public override ICommand ConfirmCommand => field ??= new AsyncDelegateCommand(SaveAsync);

    private async Task SaveAsync()
    {
        var request = new UserBillingUpdateRequest { Id = Parameter.Id };
        try
        {
            bool changed = false;
            foreach (BillingField field in Fields)
            {
                changed |= field.ApplyChange(request);
            }
            if (!changed)
            {
                OnRequestClose(new DialogResult(ButtonResult.Cancel));
                return;
            }
            ErrorMsg = "";
            IsLoading = true;
            await userService.UpdateBillingAsync(request);
        }
        catch (FormatException ex)
        {
            ErrorMsg = ex.Message;
            return;
        }
        catch (ApiException ex)
        {
            ErrorMsg = ex.Message;
            return;
        }
        finally
        {
            IsLoading = false;
        }
        OnRequestClose(new DialogResult(ButtonResult.OK));
    }
}