如何在C#中将参数传递给公共类
本文关键字:参数传递 | 更新日期: 2023-09-27 18:22:04
如何在C#中将参数传递给公共类。我是C#的新手,所以请原谅n00b的问题。
给定这个样本类别:
public class DoSomething
{
public static void Main(System.String[] args)
{
System.String apple = args[0];
System.String orange = args[1];
System.String banana = args[2];
System.String peach = args[3];
// do something
}
}
如何传递请求的参数?
我希望写这样的东西:
DoSomething ds = new DoSomething();
ds.apple = "pie";
但这失败了。
首先,让我们用注释来了解您的版本,然后继续了解您可能想要的内容。
// Here you declare your DoSomething class
public class DoSomething
{
// now you're defining a static function called Main
// This function isn't associated with any specific instance
// of your class. You can invoke it just from the type,
// like: DoSomething.Main(...)
public static void Main(System.String[] args)
{
// Here, you declare some variables that are only in scope
// during the Main function, and assign them values
System.String apple = args[0];
System.String orange = args[1];
System.String banana = args[2];
System.String peach = args[3];
}
// at this point, the fruit variables are all out of scope - they
// aren't members of your class, just variables in this function.
// There are no variables out here in your class definition
// There isn't a constructor for your class, so only the
// default public one is available: DoSomething()
}
以下是您可能想要的类定义:
public class DoSomething
{
// The properties of the class.
public string Apple;
public string Orange;
// A constructor with no parameters
public DoSomething()
{
}
// A constructor that takes parameter to set the properties
public DoSomething(string apple, string orange)
{
Apple = apple;
Orange = orange;
}
}
然后您可以创建/操作类,如下所示。在每种情况下,实例都将以Apple="foo"和Orange="bar"结束
DoSomething X = new DoSomething("foo", "bar");
DoSomething Y = new DoSomething();
Y.Apple = "foo";
Y.Orange = "bar";
DoSomething Z = new DoSomething()
{
Apple = "foo",
Orange = "bar"
};
Main
方法的String[] args
参数在通过命令行启动应用程序时填充:
/your/application/path/DoSomething.exe arg1 arg2 arg3 ...
如果你想以编程方式传递这些参数,你必须将变量设置为公共属性,例如:
public class DoSomething
{
public string Apple { get; set; }
public string Orange { get; set; }
public string Banana { get; set; }
// other fruits...
}
然后你可以做:
public class Test
{
public static void Main(System.String[] args)
{
DoSomething ds = new DoSomething();
ds.Apple = "pie";
// do something
}
}
使用公共属性,可以使用自动实现的属性以开头
public class DoSomething
{
public string Apple {get;set;}
}
构造函数:
public class DoSomething
{
public DoSomething(String mystring) { ... }
static void Main(String[] args) {
new DoSomething(args[0]);
}
}
编辑
注意到C#在线图书是德语的。但我确信也有英文书。
在您提供的示例中,您正在创建的变量的作用域在Main
方法中;它们不是类级别的变量。
您可以通过使它们成为类的成员来访问它们,如下所示:
我最初的代码片段是错误的;Main
方法是静态的,因此不能访问实例变量。
public class DoSomething
{
public string apple;
public void Main(System.String[] args)
{
apple = args[0];
}
}