要解决ASP.NET的Google Reporting API与Google Analytics仪表板不同的问题，可以尝试以下解决方法：

1. 确保使用相同的指标和维度：Google Reporting API和Google Analytics仪表板使用不同的术语和参数名称来表示指标和维度。确保在调用Google Reporting API时使用与Google Analytics仪表板相同的指标和维度。

以下是使用Google Reporting API获取网站访问量的示例代码：

using Google.Apis.AnalyticsReporting.v4;
using Google.Apis.Auth.OAuth2;
using Google.Apis.Services;
using Google.Apis.Util.Store;
using System;
using System.Collections.Generic;
using System.IO;
using System.Threading;

namespace GoogleReportingAPIExample
{
    class Program
    {
        static void Main(string[] args)
        {
            // 设置要连接的Google Analytics视图ID
            string viewId = "your-view-id";

            // 创建Google API凭据
            UserCredential credential;
            using (var stream = new FileStream("credentials.json", FileMode.Open, FileAccess.Read))
            {
                string credPath = "token.json";
                credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
                    GoogleClientSecrets.Load(stream).Secrets,
                    new[] { AnalyticsReportingService.Scope.AnalyticsReadonly },
                    "user",
                    CancellationToken.None,
                    new FileDataStore(credPath, true)).Result;
            }

            // 创建Google Analytics Reporting服务
            var service = new AnalyticsReportingService(new BaseClientService.Initializer()
            {
                HttpClientInitializer = credential,
                ApplicationName = "Google Reporting Example"
            });

            // 创建报告请求
            var request = new GetReportsRequest
            {
                ReportRequests = new List
                {
                    new ReportRequest
                    {
                        ViewId = viewId,
                        DateRanges = new List { new DateRange { StartDate = "2021-01-01", EndDate = "2021-01-31" } },
                        Dimensions = new List { new Dimension { Name = "ga:date" } },
                        Metrics = new List { new Metric { Expression = "ga:sessions", Alias = "Sessions" } }
                    }
                }
            };

            // 发送报告请求
            var response = service.Reports.BatchGet(request).Execute();

            // 处理报告响应
            foreach (var report in response.Reports)
            {
                foreach (var row in report.Data.Rows)
                {
                    Console.WriteLine("Date: {0}, Sessions: {1}", row.Dimensions[0], row.Metrics[0].Values[0]);
                }
            }
        }
    }
}

请替换your-view-id为您的Google Analytics视图ID，并确保您具有适当的凭据文件（credentials.json）和访问权限。

2. 确保正确设置权限：确保您的Google API凭据具有足够的权限来访问Google Analytics数据。在Google Cloud控制台中，确保您的凭据具有适当的Google Analytics API权限。

3. 检查日期范围：确保在调用Google Reporting API时使用与Google Analytics仪表板相同的日期范围。确认您正在检索相同的日期范围内的数据。

通过采取这些步骤，您应该能够解决ASP.NET的Google Reporting API与Google Analytics仪表板不同的问题。