在Swift中发送带有循环正文的电子邮件

Question

我想发送一封电子邮件与不同的步骤和值取决于用户已编辑的图像。为此，我使用UserDefaults来保存值。

然后，我将下一段代码转换为UIAlertController：

alert.addAction(UIAlertAction(title: "Send", style: .default)
        { action -> Void in
            //i is the last step register

            let nombre = alert.textFields![0]

            for n in 1...self.i {
                print("Step \(n): \(self.filterUserDefaults.string(forKey: "Step_\(n)")!)")
            }

            let filters = [
                "Brillo",
                "Exposicion",
                "Contraste",
                "Saturacion",
                "Saturacion_color",
                "Temperatura",
                "Blanco_Negro",
                "HUE",
                "Tintado_Rojo",
                "Tintado_Rosa",
                "Tintado_Naranja",
                "Tintado_Amarillo",
                "Tintado_Purpura",
                "Tintado_Verde",
                "Tintado_Azul",
                "Tintado_Marron",
                "Tintado_Gris"]
            for filter in filters {
                print("\(filter) = \(self.filterUserDefaults.float(forKey: filter).roundTo(places: 3))")
            }
            self.sendMail(filtro: nombre.text!, body: "XXXX")
        })
        present(alert, animated: true)
    }
    func sendMail(filtro: String, body: String) {
        if MFMailComposeViewController.canSendMail() {
            let mail = MFMailComposeViewController()
            mail.mailComposeDelegate = self
            mail.setToRecipients(["blablabla@gmail.com"])
            mail.setSubject("Filtro \(filtro)")
            mail.setMessageBody(body, isHTML: true)
            present(mail, animated: true)
        } else {
            print("Error presenting email app.")
        }
    }

所以打印工作与我预期的一样，但问题是要将这些打印放入sendMail函数的主体中……

我试过了：

            var steps: [String]?

            for n in 1...self.i {
                steps = ["Step \(n): \(self.filterUserDefaults.string(forKey: "Step_\(n)")!)"]
            }
            .
            .
            .
            self.sendMail(filtro: nombre.text!, body: steps!.joined(separator: "\n"))

但只有最后一步会写入正文的电子邮件中，而不是数组中...

有谁能帮帮我吗？

提前谢谢你！

Answer 1

现在就差不多了，需要初始化数组变量并使用append

var steps = [String]()

for n in 1...self.i {
    steps.append("Step \(n): \(self.filterUserDefaults.string(forKey: "Step_\(n)")!)")
}
...
self.sendMail(filtro: nombre.text!, body: steps.joined(separator: "\n"))

Answer 2

你可以试试下面的代码

var steps: String = ""
for n in 1...self.i {
steps += "Step \(n): \(self.filterUserDefaults.string(forKey: "Step_\(n)")!)"
}