如何正确设置UIView的alpha？ [iOS的]

我有UIView有很多子视图(UILabel,UITextView等).

如果设置alpha 0.6到主视图所有子视图都采用此alpha.

如何分别设置主视图的alpha？

解决方法

[view setBackgroundColor:[[UIColor clearColor] colorWithAlphaComponent:0.5]];

 //try this.. dont try to set alpha of UIView and also your subviews will not affect