Value type trap for struct in foreach

Recently stepped on a hole, in order to optimize the code, the class changed to a struct, the results found that the original initialization statement did not expect to run, pseudo-code as follows:

 Public struct a{    bool  _isactive;      Public void Init (bool  isActive)    {        = isActive;    }}

    Public//Call the following foreach in _arraya) {a.init ()    ;}

It looks as if it can be expected, but it's not.

In foreach, a temporary variable is usually copied, except that the value type, which is copied with a new value type, is also the new value type, not the contents of the array, but the reference type copies the reference to the same content. So the use of the new copy of the reference will be applied to the content we expect.
Therefore, you should replace foreach with a For loop.

 for (int0; i < _arraya.length; i++) {    _arraya[i]. Init ();}

If you want to know more about these, the following articles are recommended:

Http://stackoverflow.com/questions/5663783/in-net-using-foreach-to-iterate-an-instance-of-ienumerablevaluetype-will-c

Value type trap for struct in foreach