C#中动态字符串中的变量

Question

我有一个通过 SMS 发送消息的模块。如果消息是静态的，我可以将变量放在字符串中，但是用户请求消息可以随意更改。

我创建了这个变量

1. 公司名称
2. 客户姓名
3. 账单号码
4. 付款

例子：

来自{公司}。 {CustomerName} 先生/女士，您好，您的帐单号码是 {BillNumber}，总付款为 {Payment}。我们想通知您 物品已完成并可以收集。

我当前的代码适用于静态消息，

string messageSms = "From " +Company+ ". Hi Mr/Mrs "+{CustomerName}+", your bill number is "+{BillNumber}+" with a total payment of "+{Payment}+". We want to inform you the items has been completed and ready for collection.";

但是如何处理动态消息呢？如何检测字符串中的变量并在变量上设置数据？

我也关注这个article，但帮助不大。

Answer 1

假设我理解，我认为String.Inject 课程可能会有所帮助。图片一个名为String.Format：

"Hello, {company}!".Inject(new { company = "StackOverflow" });
// "Hello, StackOverflow!"

另一个好处是您可以拥有一个硬编码模型并直接引用它的属性。例如

class Contact
{
    string FirstName;
    string LastName;
}

String greeting = "Mr. {FirstName} {LastName}, Welcome to the site ...";
String result = greeting.Inject(new Contact
{
    FirstName = "Brad",
    LastName = "Christie"
});

Answer 2

var newString = messageSms.Replace("{Company}", CompanyName)
                          .Replace("{CustomerName}", CustomerName) // ...etc

应该这样做。

Answer 3

您也可以在 C# 6.0 中使用 interpolated strings

var messageSms = $"From {companyName}. Hi {customerName}, your bill number is {billNumber} with a total payment of {payment}.";

Answer 4

我会采用以下方法：

string Company;
string CustomerName;
string BillNumber;
string Payment;

string messageSms = $@"
From {Company}. Hi Mr/Mrs {CustomerName}, your bill number is {BillNumber} 
with a total payment of {Payment}. We want to inform you the items has been 
completed and ready for collection.
";

Answer 5

试试String.Format方法，例如：

string messageSms = String.Format("From {0}. Hi ..{1}, Your..{2} with..{3}. We..", 
                                  CompanyName, CustomerName, BillNumber, Payment);

Answer 6

我认为实现这一目标的最简单方法（您没有澄清您的问题）是使用string.Format()。 像这样使用它：

string company = ...;
string name= ...;
string billNr= ...;
string payment= ...;
string output = string.Format("From {0}. Hi Mr/Mrs {1}, your bill number is {2} with a total payment of {3}. We want to inform you the items has been completed and ready for collection.", company, name, billNr, payment);

Answer 7

为什么不改用StringBuilder？

StringBuilder stringBuilder = new StringBuilder("From {Company}.Hi Mr/Mrs {CustomerName}, your bill number is {BillNumber} with a total payment of {Payment}. We want to inform you the items has been completed and ready for collection.");
stringBuilder.Replace("{Company}",CompanyName);
stringBuilder.Replace("{CustomerName}",CustomerName);
stringBuilder.Replace("{BillNumber}",BillNumber);
stringBuilder.Replace("{Payment}",Payment);
string messageSms = stringBuilder.ToString();

Answer 8

要创建一个可重用的解决方案，您可以首先声明一个包含替换值作为属性的对象。在这种情况下，我只是声明了一个匿名对象，但普通类也可以工作：

var data = new {
  Company = "Stack Overflow",
  CustomerName = "Martin Liversage",
  BillNumber = 123456,
  Payment = 1234.567M.ToString("N2")
};

注意我如何“作弊”并将字符串分配给Payment。数字和日期/时间格式始终是一个复杂的问题，我决定在声明数据对象时预先进行格式设置。相反，您可以在格式化引擎中构建一些或多或少复杂的格式化规则。

拥有一个具有属性的数据对象，我可以构建一个名称/值对的字典：

var dictionary = data
  .GetType()
  .GetProperties()
  .ToDictionary(
    propertyInfo => propertyInfo.Name,
    propertyInfo => propertyInfo.GetValue(data, null)
  );

假设format 包含格式化模板，那么只需遍历字典中的元素即可创建替换字符串：

var buffer = new StringBuilder(format);
foreach (var name in dictionary.Keys) {
  var value = dictionary[name].ToString();
  buffer.Replace("{" + name + "}", value);
}
var message = buffer.ToString();