ExcelHelper/Views/ViewModels/ImportViewModel.cs

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Windows.Controls;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using CommunityToolkit.Mvvm.Messaging;
using ExcelHelper.Message;
using MiniExcelLibs;

namespace ExcelHelper.Views.ViewModels;


public partial class ImportViewModel : ObservableRecipient, IViewModel
{

    public void FileDrop(string[] files)
    {
        IsLoading = true;
        ExcelFiles.Clear();
        SelectedSheetName = null;
        Sheets.Clear();
        MaxRow = 0;
        foreach (var item in files)
        {
            ExcelFiles.Add(item);
        }
        //ReadForExcel(ExcelFiles.First());
        CurrentFilePath = ExcelFiles.FirstOrDefault();
        IsLoading = false;
    }

    public async void ReadForExcel(string path)
    {
        IsLoading = true;
        //await Task.Factory.StartNew(async () =>
        //{
        try
        {
            if (string.IsNullOrEmpty(path)) return;
            var excelData = await MiniExcel.QueryAsync(path, sheetName: SelectedSheetName, useHeaderRow: UseHeaderRow, startCell: StartCell);
            if (MaxRow != 0)
            {
                ExcelData = excelData.Take(Math.Min(MaxRow, 300));
            }
            else
            {
                ExcelData = excelData.Take(300);
            }
            var columns = MiniExcel.GetColumns(path, useHeaderRow: UseHeaderRow, startCell: StartCell, sheetName: SelectedSheetName);
            GenColumns(columns);
            GetSheets(path);
            MaxRow = ExcelData.Count();
        }
        catch (Exception ex)
        {
            WeakReferenceMessenger.Default.Send(new ErrorDialogMessage($"出现了异常!{ex}"));
        }
        IsLoading = false;
        //}).ContinueWith(x =>
        // {


        // });
    }
    private void GenColumns(IEnumerable<string> columns)
    {
        ExcelColumns.Clear();
        if (UseHeaderRow)
        {

            foreach (var columnName in columns)
            {
                var column = new DataGridTextColumn
                {
                    Header = columnName,
                    Binding = new System.Windows.Data.Binding($"{columnName}"),
                    Width = DataGridLength.Auto
                };
                ExcelColumns.Add(column);
            }
        }
        else
        {
            for (var i = 'A'; i < 'Z'; i++)
            {
                var column = new DataGridTextColumn
                {
                    Header = $"{i}",
                    Binding = new System.Windows.Data.Binding($"{i}"),
                    Width = DataGridLength.Auto
                };
                ExcelColumns.Add(column);
            }
        }
        if (ExcelColumns.Count > 0)
            WeakReferenceMessenger.Default.Send(new UpdateDataGridColumnsMessage([.. ExcelColumns]));
        else
        {
            WeakReferenceMessenger.Default.Send(new ErrorDialogMessage("未读取到列信息!"));
        }
    }

    [RelayCommand]
    private void OnReLoadExcel()
    {
        ReadForExcel(CurrentFilePath);
    }
    [RelayCommand]
    private void OnReadSheets()
    {
        if (string.IsNullOrWhiteSpace(CurrentFilePath))
        {
            GetSheets(CurrentFilePath);
        }
    }
    private void GetSheets(string excelPath)
    {
        if (Sheets == null)
        {
            Sheets = new ObservableCollection<string>();
        }
        else
        {
            Sheets.Clear();
        }
        MiniExcel.GetSheetNames(excelPath)?.ForEach(sheetName =>
        {
            Sheets.Add(sheetName);
        });
        SelectedSheetName = Sheets.FirstOrDefault();
    }

    #region Props
    [ObservableProperty]
    private IEnumerable<dynamic> _excelData;

    [ObservableProperty]
    private ObservableCollection<string> _excelFiles = [];

    [ObservableProperty]
    private ObservableCollection<DataGridColumn> _excelColumns = [];

    /// <summary>
    /// 是否正在加载
    /// </summary>
    [ObservableProperty]
    private bool _isLoading = false;

    /// <summary>
    /// 使用首行作为表头
    /// </summary>
    [ObservableProperty]
    private bool _useHeaderRow = false;

    /// <summary>
    /// 选中的Sheet
    /// </summary>
    [ObservableProperty]
    private string _selectedSheetName;

    /// <summary>
    /// Sheets列表
    /// </summary>
    [ObservableProperty]
    private ObservableCollection<string> _sheets = [];
    /// <summary>
    /// 起始位置
    /// </summary>
    [ObservableProperty]
    private string _startCell = "A1";
    /// <summary>
    /// 结束位置
    /// </summary>
    [ObservableProperty]
    private string _endCell;
    /// <summary>
    /// 最大行数
    /// </summary>
    [ObservableProperty]
    private int _maxRow = 0;

    /// <summary>
    /// 当前文件路径
    /// </summary> 
    private string _currentFilePath;
    public string CurrentFilePath
    {
        get => _currentFilePath;
        set
        {
            SetProperty(ref _currentFilePath, value);
            ReadForExcel(value);
        }
    }

    /// <summary>
    /// Excel文件密码
    /// </summary>
    [ObservableProperty]
    private string _excelPassword;

    #endregion
}