wpf c#进度条只有在后台工作完成后才会更新

using System;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Threading;

namespace WpfApp
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private async void StartButton_Click(object sender, RoutedEventArgs e)
        {
            // 启动后台任务
            await DoBackgroundWork();

            // 后台任务完成后更新进度条
            UpdateProgressBar();
        }

        private async Task DoBackgroundWork()
        {
            // 模拟后台任务
            await Task.Delay(5000);
        }

        private void UpdateProgressBar()
        {
            // 在UI线程更新进度条
            Dispatcher.Invoke(() =>
            {
                ProgressBar.Value = 100;
            });
        }
    }
}