为什么必须使用非默认构造函数初始化C＃struct中的所有字段？

I would like to try this code:

我想试试这段代码:

public struct Direction
{
   private int _azimuth;

   public int Azimuth
   {
     get { return _azimuth; }
     set { _azimuth = value; }
   }       

   public Direction(int azimuth)
   { 
      Azimuth = azimuth
   } 
}
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