如何使用 Microsoft Graph 在电子邮件正文中嵌入图像

Question

我正在使用函数应用程序触发邮件，使用 MS Graph API，邮件正文文本被正确触发，但在渲染如图所示的页眉和页脚图像时遇到问题。如何从身体层面解决这个问题。

以下是上述图像在 HTML/Blob 文件中的引用

  <img src=cid:Header.jpg>
    <img src=cid:footer.png>
    <ContentIDs>Header.jpg, footer.png</ContentIDs>

用于渲染主体的代码。

             var mailContent = new Message
                {
                    Subject = em.Subject,
                    Body = new ItemBody
                    {
                        ContentType = BodyType.Html,
                        Content = m.Body,
                        ODataType = null
                    },
                    ToRecipients = toEmails,
                    CcRecipients = ccEmails,
                    ODataType = null
                };    

编辑： 在此更改后，当前功能应用程序中面临错误请求。我正在努力解决这个问题。如果您发现下面的代码有任何差异，请随时发表评论。

            var imagePath = @"<path\Header.jpg>";
            var imageID = "Header.jpg";//file name
            byte[] imageArray = System.IO.File.ReadAllBytes(imagePath);
            var imagePath2 = @"<path\footer.png">;
            var imageID2 = "footer.png";
            byte[] imageArray2 =System.IO.File.ReadAllBytes(imagePath2);

            
            var mContent = new Message
            {
                Subject = t.Subject,//parsing from the template
                Body = new ItemBody
                {
                    ContentType = BodyType.Html,
                    Content = m.Body,
                    ODataType = "#microsoft.graph.fileAttachment"
                },
                ToRecipients = toEmails,
                CcRecipients = ccEmails,
                ODataType = "#microsoft.graph.fileAttachment",
                HasAttachments = true,
                Attachments = new MessageAttachmentsCollectionPage()
                    {
                            new FileAttachment
                        {
                                
                                ContentBytes= imageArray,
                                ContentType = "image/jpeg",
                                ContentId= imageID,
                                IsInline=true,
                                Name = "theHead",
                               
                        },
                            new FileAttachment
                            {
                                
                                ContentBytes= imageArray2,
                                ContentType = "image/png",
                                ContentId= imageID2,
                                IsInline=true,
                                Name = "thefoot",
                            }
                    }
            };

Answer 1

我为你写了一个演示，尝试下面的简单控制台应用程序：

using Microsoft.Graph;
using Microsoft.Graph.Auth;
using Microsoft.Identity.Client;
using System;
using System.Collections.Generic;

namespace sendEmails
{
    class Program
    {
        static void Main(string[] args)
        {
            var appID = "";
            var appSec = "";
            var tenantID = "";
            

            IConfidentialClientApplication confidentialClientApplication = ConfidentialClientApplicationBuilder
                .Create(appID)
                .WithTenantId(tenantID)
                .WithClientSecret(appSec)
                .Build();

            ClientCredentialProvider authenticationProvider = new ClientCredentialProvider(confidentialClientApplication);

            GraphServiceClient graphServiceClient = new GraphServiceClient(authenticationProvider);

            var imagePath = @"<your image path>";
            var imageID = "image1";
            

            byte[] imageArray = System.IO.File.ReadAllBytes(imagePath);

            var body = "<h1>this is superman </br> <img src='cid:"+ imageID + "'/></h1>";
            var attachments = new MessageAttachmentsCollectionPage()
            {
                new FileAttachment{
                    ContentType= "image/jpeg",
                    ContentBytes = imageArray,
                    ContentId = imageID,
                    Name= "test-image"
                }
            };
            
            var message = new Message
            {
                Subject = "TEST SENDING IMAGE ",
                Body = new ItemBody
                {
                    ContentType = BodyType.Html,
                    Content = body,
                    ODataType = null
                },
                ToRecipients = new List<Recipient>()
                {
                    new Recipient
                    {
                        EmailAddress = new EmailAddress
                        {
                            Address = "<receiver email>"
                        }
                    }
                },
                Attachments = attachments

            };
            
            graphServiceClient.Users["<user upn>"].SendMail(message, false).Request().PostAsync().GetAwaiter().GetResult();
            Console.WriteLine("ok");
        }
    }
}

结果：

Answer 2

这是另一种将图像嵌入到使用 Microsoft Graph 发送的电子邮件中的简单方法，特别适合徽标等小图像。

首先，转到将文件转换为 Base64 的免费网站之一（例如此处）。 然后，使用编码的图像字符串作为消息正文中 标签的 src。

const string image = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAGNCAMAAAAIKde7AAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR ...";

Message message = new()
{
    ...,
    Body = new ItemBody
    {
        ContentType = BodyType.Html,
        Content = $@"<img width=500 height=500 alt=""Your alt text"" src=""{image}"">"
        }
    }
}

这样，您就不必弄乱附件了。