private async Task CreateFolderAsync() { await ftpSemaphore.WaitAsync(); try { DialogContentWithTextBox content = new DialogContentWithTextBox(); content.ContentText = "新文件夹名称:"; ContentDialog dialog = new ContentDialog() { Content = content, PrimaryButtonText = "确定", CloseButtonText = "取消" }; if (await dialog.ShowAsync() == ContentDialogResult.Primary) { progressBar.IsIndeterminate = true; progressBar.Visibility = Visibility.Visible; var currentPath = currentAddress.LocalPath + currentAddress.Fragment; await client.SetWorkingDirectoryAsync(currentPath); await client.CreateDirectoryAsync(content.TextBoxText); } } finally { progressBar.Visibility = Visibility.Collapsed; ftpSemaphore.Release(); } }