通过结构成员迭代 [英] Iterating through Struct members

问题描述

假设我们有一个结构

 结构体MYSTRUCT 
 {
 INT VAR1; 
 INT VAR2; 
串VAR3; 
。 
。 
} 
  

是否有可能通过可能使用的foreach通过结构成员重复？我已阅读反思一些东西，但我不知道如何应用在这里。

有在结构中约20变数。我想读值
关文件，并试图将它们分配给变量，但不希望
调用file.ReadLine（）的20倍。我想通过一个循环

解决方案

您应用访问该成员
变量在几乎相同的方式与普通的反射，使用 Type.GetFields ：

  MYSTRUCT structValue =新MYSTRUCT（...）; 
 
的foreach（typeof运算中的VAR场（MYSTRUCT）.GetFields（BindingFlags.Instance | 
 BindingFlags.NonPublic可| 
 BindingFlags.Public））
 {
 Console.WriteLine（{0} = {1}，field.Name，field.GetValue（structValue））; 
} 
  

请注意，如果结构暴露性质（因为它几乎肯定应该）你可以使用 Type.GetProperties 来得到那些。

（正如在评论中指出，这很可能不是一个好事情在首位做的，一般的我很可疑用户定义的结构，但我想我会包括实际的答案反正...）

编辑：现在看来，你有兴趣的设置的领域，也由于这样的值类型作品的稍微复杂（是的，这确实的不应该'T 的是一个结构）你会想框的一次的，对单一包装实例，并在年底再拆箱设定值：

 对象盒装=新MYSTRUCT（）; 
 
 //调用FieldInfo.SetValue（盒装，newValue）以等
 
 MYSTRUCT拆箱=（MYSTRUCT）盒装; 
  

Lets say we have a struct

Struct myStruct
{
   int var1;
   int var2;
   string var3;
   .
   .
}

Is it possible to to iterate through the structure's members by maybe using foreach? I have read some things on reflection, but I am not sure how to apply that here.

There are about 20 variables in the struct. I am trying to read values off a file and trying to assign them to the variables but don't want to call file.ReadLine() 20 times. I am trying to access the member variables through a loop

解决方案

You apply reflection in pretty much the same way as normal, using Type.GetFields:

MyStruct structValue = new MyStruct(...);

foreach (var field in typeof(MyStruct).GetFields(BindingFlags.Instance |
                                                 BindingFlags.NonPublic |
                                                 BindingFlags.Public))
{
     Console.WriteLine("{0} = {1}", field.Name, field.GetValue(structValue));
}

Note that if the struct exposes properties (as it almost certainly should) you could use Type.GetProperties to get at those.

(As noted in comments, this may well not be a good thing to do in the first place, and in general I'm suspicious of user-defined structs, but I thought I'd include the actual answer anyway...)

EDIT: Now it seems you're interested in setting the fields, that's slightly more complicated due to the way value types work (and yes, this really shouldn't be a struct.) You'll want to box once, set values on the single boxed instance, and then unbox at the end:

object boxed = new MyStruct();

// Call FieldInfo.SetValue(boxed, newValue) etc

MyStruct unboxed = (MyStruct) boxed;

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