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1. 前言
最近pm临时提出了多种邮件验证操作的需求，因为一时间也没有找到好的邮件收发组件，也抱着研究ABP的心态，就花了几小时时间探究了一下ABP中关于Email的处理和操作。其实邮件操作大多大同小异，这次只是希望介绍一下ABP中实现功能的代码结构而已，以下是具体过程
演示的ABP代码版本为0.9.0.0，不过后面版本对于这部分的修改较少，所以完全不影响之后版本的移植使用
2. 实现过程
ABP的Mail操作放在了Abp.Net.Mail和Abp.Net.Mail.smtp中，第一步先让我们直接看看这个文件夹下类及接口的代码图（未经允许不可使用）
1. 代码图（重）
根据代码图可以发现ABP对于Mail处理主要由三部分组成
- 第一部分是通过继承SettingProvider的EmailSettingProvider来对Mail相关参数进行设置（其中EmailSettingNames定义相关字符串）
- 第二部分是以IEmailSenderConfiguration接口为基派生出的对SettingProvider设置的邮件参数进行读取和传输的相关操作类
- 第三部分是以IEmailSender接口为基派生出的Mail发送操作相关类
至于Smtp开头的文件，则是以Smtp形式进行邮件发送的一种实现文件而已，后文也将直接使用该种方式进行处理
2.具体实现
在具体的实现上，我发现ABP本身的Mail相关类已经十分完整，只是在邮件参数的配置上需要采取自定义的实现，所以我直接抽取了ABP的源码来进行演示
2.1 定义AppSettingNames及AppSettingProvider
AppSettingNames中定义相关的唯一字符串，大家可以认为是Key，而AppSettingProvider中则是将Key对应的邮件参数赋值，供之后的Configuration读取
邮件功能推荐放在Core模块中，完成相关的provider后在CoreModule加入
Configuration.Settings.Providers.Add<AppSettingProvider>();即可生效
public static class AppSettings { /// <summary> /// SMTP related email settings. /// </summary> public static class Smtp { /// <summary> /// Abp.Net.Mail.DefaultFromAddress /// </summary> public const string DefaultAddress = "Trucking.Net.Mail.DefaultFromAddress"; /// <summary> /// Abp.Net.Mail.DefaultFromDisplayName /// </summary> public const string DefaultDisplayName = "Trucking.Net.Mail.DefaultFromDisplayName"; /// <summary> /// Abp.Net.Mail.Smtp.Host /// </summary> public const string Host = "Trucking.Net.Mail.Smtp.Host"; /// <summary> /// Abp.Net.Mail.Smtp.Port /// </summary> public const string Port = "Trucking.Net.Mail.Smtp.Port"; /// <summary> /// Abp.Net.Mail.Smtp.UserName /// </summary> public const string UserName = "Trucking.Net.Mail.Smtp.UserName"; /// <summary> /// Abp.Net.Mail.Smtp.Password /// </summary> public const string Password = "Trucking.Net.Mail.Smtp.Password"; /// <summary> /// Abp.Net.Mail.Smtp.Domain /// </summary> public const string Domain = "Trucking.Net.Mail.Smtp.Domain"; /// <summary> /// Abp.Net.Mail.Smtp.EnableSsl /// </summary> public const string EnableSsl = "Trucking.Net.Mail.Smtp.EnableSsl"; /// <summary> /// Abp.Net.Mail.Smtp.UseDefaultCredentials /// </summary> public const string UseDefaultCredentials = "Trucking.Net.Mail.Smtp.UseDefaultCredentials"; } } public class AppSettingProvider : SettingProvider { public override IEnumerable<SettingDefinition> GetSettingDefinitions(SettingDefinitionProviderContext context) { return new[] { new SettingDefinition(AppSettings.Smtp.Host, "smtp.gmail.com", L("SmtpHost"), scopes: SettingScopes.Application | SettingScopes.Tenant), new SettingDefinition(AppSettings.Smtp.Port, "587", L("SmtpPort"), scopes: SettingScopes.Application | SettingScopes.Tenant), new SettingDefinition(AppSettings.Smtp.UserName, "myemail@gmail.com", L("Username"), scopes: SettingScopes.Application | SettingScopes.Tenant), new SettingDefinition(AppSettings.Smtp.Password, "mypassword", L("Password"), scopes: SettingScopes.Application | SettingScopes.Tenant), new SettingDefinition(AppSettings.Smtp.Domain, "", L("DomainName"), scopes: SettingScopes.Application | SettingScopes.Tenant), new SettingDefinition(AppSettings.Smtp.EnableSsl, "true", L("UseSSL"), scopes: SettingScopes.Application | SettingScopes.Tenant), new SettingDefinition(AppSettings.Smtp.UseDefaultCredentials, "false", L("UseDefaultCredentials"), scopes: SettingScopes.Application | SettingScopes.Tenant), new SettingDefinition(AppSettings.Smtp.DefaultAddress, "myemail@gmail.com", L("DefaultEmailAddress"), scopes: SettingScopes.Application | SettingScopes.Tenant), new SettingDefinition(AppSettings.Smtp.DefaultDisplayName, "CompanyName", L("DefaultDisplayName"), scopes: SettingScopes.Application | SettingScopes.Tenant) }; } private static LocalizableString L(string name) { return new LocalizableString(name, AbpConsts.LocalizationSourceName); } }
2.2 EmailSenderConfiguration配置
这个类的作用如上面提到的那样，主要是读取自定义的AppSettingProvider中设置的邮件参数值
IUserEmailSenderConfiguration接口略
public class UserEmailSenderConfiguration : TruckingServiceBase, IUserEmailSenderConfiguration, ITransientDependency { /// <summary> /// Gets a setting value by checking. Throws <see cref="AbpException"/> if it's null or empty. /// </summary> /// <param name="name">Name of the setting</param> /// <returns>Value of the setting</returns> protected string GetNotEmptySettingValue(string name) { var value = SettingManager.GetSettingValue(name); if (value.IsNullOrEmpty()) { throw new AbpException(String.Format("Setting value for '{0}' is null or empty!", name)); } return value; } /// <summary> /// SMTP Host name/IP. /// </summary> public string Host { get { return GetNotEmptySettingValue(AppSettings.Smtp.Host); } } /// <summary> /// SMTP Port. /// </summary> public int Port { get { return SettingManager.GetSettingValue<int>(AppSettings.Smtp.Port); } } /// <summary> /// User name to login to SMTP server. /// </summary> public string UserName { get { return GetNotEmptySettingValue(AppSettings.Smtp.UserName); } } /// <summary> /// Password to login to SMTP server. /// </summary> public string Password { get { return GetNotEmptySettingValue(AppSettings.Smtp.Password); } } /// <summary> /// Domain name to login to SMTP server. /// </summary> public string Domain { get { return SettingManager.GetSettingValue(AppSettings.Smtp.Domain); } } /// <summary> /// Is SSL enabled? /// </summary> public bool EnableSsl { get { return SettingManager.GetSettingValue<bool>(AppSettings.Smtp.EnableSsl); } } /// <summary> /// Use default credentials? /// </summary> public bool UseDefaultCredentials { get { return SettingManager.GetSettingValue<bool>(AppSettings.Smtp.UseDefaultCredentials); } } public string DefaultAddress { get { return GetNotEmptySettingValue(AppSettings.Smtp.DefaultAddress); } } public string DefaultDisplayName { get { return SettingManager.GetSettingValue(AppSettings.Smtp.DefaultDisplayName); } } }
2.3 SmtpEmailSender实现（Smtp实现邮件发送）
UserSmtpEmailSender类才是真正的对Mail操作类，它通过注入IUserEmailSenderConfiguration接口，读取相关的Mail参数，如Host，UserName，Password等，然后再调用.NET的Mail发送邮件。
IUserSmtpEmailSender接口略
public class UserSmtpEmailSender : IUserSmtpEmailSender, ITransientDependency { private readonly IUserEmailSenderConfiguration _configuration; public UserSmtpEmailSender(IUserEmailSenderConfiguration configuration) { _configuration = configuration; } public async Task SendAsync(string to, string subject, string body, bool isBodyHtml = true) { await SendAsync(_configuration.DefaultAddress, to, subject, body, isBodyHtml); } public void Send(string to, string subject, string body, bool isBodyHtml = true) { Send(_configuration.DefaultAddress, to, subject, body, isBodyHtml); } public async Task SendAsync(string from, string to, string subject, string body, bool isBodyHtml = true) { await SendAsync(new MailMessage(from, to, subject, body) {IsBodyHtml = isBodyHtml}); } public void Send(string from, string to, string subject, string body, bool isBodyHtml = true) { Send(new MailMessage(from, to, subject, body) {IsBodyHtml = isBodyHtml}); } public async Task SendAsync(MailMessage mail, bool normalize = true) { if (normalize) NormalizeMail(mail); await SendEmailAsync(mail); } public void Send(MailMessage mail, bool normalize = true) { if (normalize) NormalizeMail(mail); SendEmail(mail); } public SmtpClient BuildClient() { var host = _configuration.Host; var port = _configuration.Port; var smtpClient = new SmtpClient(host, port); try { if (_configuration.EnableSsl) smtpClient.EnableSsl = true; if (_configuration.UseDefaultCredentials) { smtpClient.UseDefaultCredentials = true; } else { smtpClient.UseDefaultCredentials = false; var userName = _configuration.UserName; if (!userName.IsNullOrEmpty()) { var password = _configuration.Password; var domain = _configuration.Domain; smtpClient.Credentials = !domain.IsNullOrEmpty() ? new NetworkCredential(userName, password, domain) : new NetworkCredential(userName, password); } } return smtpClient; } catch { smtpClient.Dispose(); throw; } } /// <summary> /// Normalizes given email. /// Fills <see cref="MailMessage.From" /> if it's not filled before. /// Sets encodings to UTF8 if they are not set before. /// </summary> /// <param name="mail">Mail to be normalized</param> protected virtual void NormalizeMail(MailMessage mail) { if ((mail.From == null) || mail.From.Address.IsNullOrEmpty()) mail.From = new MailAddress( _configuration.DefaultAddress, _configuration.DefaultDisplayName, Encoding.UTF8 ); if (mail.HeadersEncoding == null) mail.HeadersEncoding = Encoding.UTF8; if (mail.SubjectEncoding == null) mail.SubjectEncoding = Encoding.UTF8; if (mail.BodyEncoding == null) mail.BodyEncoding = Encoding.UTF8; } protected async Task SendEmailAsync(MailMessage mail) { using (var smtpClient = BuildClient()) { await smtpClient.SendMailAsync(mail); } } protected void SendEmail(MailMessage mail) { using (var smtpClient = BuildClient()) { smtpClient.Send(mail); } } }
之后我们只需要再调用该EmailSender的SendAsync，填入对应的参数，亲测有效。如果之后要更换邮件组件，则只需要实现对应的UserLibraryEmailSerder即可。
至此，我们便将ABP中单独的一个邮件功能抽离了出来并做了相关解释，其实只要花点功夫，自己手动剥离代码图也可以理解了。至于一个简单的邮件功能为什么在ABP中要实现得如此复杂，每个程序员有每个程序员的答案，还是继续学习吧
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