错误代码2015 "未选择任何维度" 是由于在调用 Bing Ads API 报告服务时未选择任何维度导致的。为了解决这个问题，你需要在请求报告时选择至少一个有效的维度。

以下是一个示例代码，展示如何选择维度来解决这个问题：

using Microsoft.BingAds;
using Microsoft.BingAds.Reporting;

public class BingAdsReportExample
{
    private static ServiceClient ReportingService;

    public static void Main(string[] args)
    {
        var customerId = "YourCustomerId";
        var accountId = "YourAccountId";
        var developerToken = "YourDeveloperToken";
        var accessToken = "YourAccessToken";
        var refreshToken = "YourRefreshToken";
        var clientSecret = "YourClientSecret";
        var clientId = "YourClientId";

        ReportingService = new ServiceClient(
            customerId: customerId,
            accountId: accountId,
            developerToken: developerToken,
            authentication: new OAuthDesktopMobileAuthCodeGrant(
                clientId,
                clientSecret,
                new OAuthTokens(accessToken, refreshToken)
            )
        );

        var request = new SubmitGenerateReportRequest
        {
            ReportRequest = new ReportRequest
            {
                Language = ReportLanguage.English,
                Format = ReportFormat.Csv,
                ReportName = "My Report",
                ReturnOnlyCompleteData = false,
                Aggregation = ReportAggregation.Daily,
                Time = new ReportTime
                {
                    PredefinedTime = ReportTimePeriod.LastSevenDays
                },
                Scope = new AccountThroughAdGroupReportScope
                {
                    AccountIds = new[] { accountId }
                },
                Columns = new[]
                {
                    ReportingDownloadColumn.AccountId,
                    ReportingDownloadColumn.CampaignId,
                    ReportingDownloadColumn.AdGroupId,
                    ReportingDownloadColumn.Impressions,
                    ReportingDownloadColumn.Clicks
                },
                Filter = new AccountThroughAdGroupReportFilter
                {
                    AdDistribution = new[] { AdDistribution.Search }
                }
            }
        };

        var response = ReportingService.Service.SubmitGenerateReport(request);
        var reportRequestId = response.ReportRequestId;
        var reportUrl = response.ReportRequestStatus.ReportDownloadUrl;

        Console.WriteLine("Report Request ID: " + reportRequestId);
        Console.WriteLine("Report Download URL: " + reportUrl);
    }
}

在这个示例中，我们创建了一个报告请求，选择了一些常见的维度和指标（AccountId、CampaignId、AdGroupId、Impressions、Clicks）。你可以根据自己的需求选择合适的维度和指标。

请确保在实际使用时替换示例代码中的占位符（如 YourCustomerId、YourAccountId 等）为你自己的有效信息。

希望这个示例能帮助你解决问题！