如何在 MVC(C#) 中刷新嵌入式 PowerBI

Question

参考：PowerBI Developer Samples

我们使用 PowerBI 和 Azure 创建了一个报告。我添加了工作区、reportid 等，并显示了报告。但是我需要在每次加载页面时更新报告（即用户刷新页面，或单击 link 重定向到报告所在的页面）。

我已经搜索过，看到您可以设置定时刷新，但是那行不通，它需要更实时。有没有办法按照我上面指定的方式刷新报告？

以下是我的控制器中的内容：

 public async Task<ActionResult> Dashboard(string username = null, string roles = null)
        {
            var result = new EmbedConfig();
            try
            {
                result = new EmbedConfig { Username = username, Roles = roles };
                var error = GetWebConfigErrors();
                if (error != null)
                {
                    result.ErrorMessage = error;
                    return View(result);
                }

                // Create a user password cradentials.
                var credential = new UserPasswordCredential(Username, Password);

                // Authenticate using created credentials
                var authenticationContext = new AuthenticationContext(AuthorityUrl);
                var authenticationResult = await authenticationContext.AcquireTokenAsync(ResourceUrl, ApplicationId, credential);

                if (authenticationResult == null)
                {
                    result.ErrorMessage = "Authentication Failed.";
                    return View(result);
                }

                var tokenCredentials = new TokenCredentials(authenticationResult.AccessToken, "Bearer");

                // Create a Power BI Client object. It will be used to call Power BI APIs.
                using (var client = new PowerBIClient(new Uri(ApiUrl), tokenCredentials))
                {
                    // Get a list of reports.
                    var reports = await client.Reports.GetReportsInGroupAsync(WorkspaceId);

                    // No reports retrieved for the given workspace.
                    if (reports.Value.Count() == 0)
                    {
                        result.ErrorMessage = "No reports were found in the workspace";
                        return View(result);
                    }

                    Report report;
                    if (string.IsNullOrWhiteSpace(ReportId))
                    {
                        // Get the first report in the workspace.
                        report = reports.Value.FirstOrDefault();
                    }
                    else
                    {
                        report = reports.Value.FirstOrDefault(r => r.Id == ReportId);
                    }

                    if (report == null)
                    {
                        result.ErrorMessage = "No report with the given ID was found in the workspace. Make sure ReportId is valid.";
                        return View(result);
                    }

                    //refreshDataset(ReportId, report.DatasetId, tokenCredentials);

                    var datasets = await client.Datasets.GetDatasetByIdInGroupAsync(WorkspaceId, report.DatasetId);
                    result.IsEffectiveIdentityRequired = datasets.IsEffectiveIdentityRequired;
                    result.IsEffectiveIdentityRolesRequired = datasets.IsEffectiveIdentityRolesRequired;
                    GenerateTokenRequest generateTokenRequestParameters;
                    // This is how you create embed token with effective identities
                    if (!string.IsNullOrWhiteSpace(username))
                    {
                        var rls = new EffectiveIdentity(username, new List<string> { report.DatasetId });
                        if (!string.IsNullOrWhiteSpace(roles))
                        {
                            var rolesList = new List<string>();
                            rolesList.AddRange(roles.Split(','));
                            rls.Roles = rolesList;
                        }
                        // Generate Embed Token with effective identities.
                        generateTokenRequestParameters = new GenerateTokenRequest(accessLevel: "view", identities: new List<EffectiveIdentity> { rls });
                    }
                    else
                    {
                        // Generate Embed Token for reports without effective identities.
                        generateTokenRequestParameters = new GenerateTokenRequest(accessLevel: "view");
                    }

                    var tokenResponse = await client.Reports.GenerateTokenInGroupAsync(WorkspaceId, report.Id, generateTokenRequestParameters);

                    if (tokenResponse == null)
                    {
                        result.ErrorMessage = "Failed to generate embed token.";
                        return View(result);
                    }

                    // Generate Embed Configuration.
                    result.EmbedToken = tokenResponse;
                    result.EmbedUrl = report.EmbedUrl;
                    result.Id = report.Id;

                    return View(result);
                }
            }
            catch (HttpOperationException exc)
            {
                result.ErrorMessage = string.Format("Status: {0} ({1})\r\nResponse: {2}\r\nRequestId: {3}", exc.Response.StatusCode, (int)exc.Response.StatusCode, exc.Response.Content, exc.Response.Headers["RequestId"].FirstOrDefault());
            }
            catch (Exception exc)
            {
                result.ErrorMessage = exc.ToString();
            }

            return View(result);
        }

下面是用于创建报告的Javascript：

<script>
        window.onload = function () {
            //Creating breadcrumbs
            $('#ribbon ol').empty();
            $('#ribbon ol').append('<li>Dashboard</li>');
        }

        // Read embed application token from Model
        var accessToken = "@Model.EmbedToken.Token";

        // Read embed URL from Model
        var embedUrl = "@Html.Raw(Model.EmbedUrl)";

        // Read report Id from Model
        var embedReportId = "@Model.Id";

        // Get models. models contains enums that can be used.
        var models = window['powerbi-client'].models;

        // Embed configuration used to describe the what and how to embed.
        // This object is used when calling powerbi.embed.
        // This also includes settings and options such as filters.
        // You can find more information at https://github.com/Microsoft/PowerBI-JavaScript/wiki/Embed-Configuration-Details.
        var config = {
            type: 'report',
            tokenType: models.TokenType.Embed,
            accessToken: accessToken,
            embedUrl: embedUrl,
            id: embedReportId,
            permissions: models.Permissions.All,
            settings: {
                filterPaneEnabled: false,
                navContentPaneEnabled: false
            }
        };

        // Get a reference to the embedded report HTML element
        var reportContainer = $('#reportContainer')[0];

        // Embed the report and display it within the div container.
        var report = powerbi.embed(reportContainer, config);
</script>

感谢您的帮助。

Answer 1

如果您的报告如 Andrey 所问，是直接查询，那么您可以致电 report.refresh() on your embedded report in the JavaScript. The difference between Direct Query and Imported is explained here。