UIView的背景颜色始终为白色

Question

我创造UIView的按钮操作如下：

-(IBAction)addSmiley{ 
    if(kSmiley == FALSE) 
    { 
     CGRect frame = CGRectMake(0, toolbar.frame.origin.y+50, 320, 50); 
     viewSmiley = [[UIView alloc]initWithFrame:frame]; 
     [viewSmiley setBackgroundColor:[UIColor blackColor]];  
     [self.view addSubview:viewSmiley]; 
     tbl.frame = CGRectMake(tbl.frame.origin.x, 0, 320, tbl.frame.size.height-50); 
     kSmiley = TRUE; 
    } 
    else 
    { 
     [viewSmiley removeFromSuperview]; 
     viewSmiley = nil; 
     [viewSmiley release]; 
     tbl.frame = CGRectMake(0, 0, 320, tbl.frame.size.height+50); 
     kSmiley = FALSE; 
    } 

} 

我能看到的UIView，但白色背景。我无法设置其背景颜色。可能是什么原因？

Answer 1

看到这个https://developer.apple.com/library/ios/#documentation/WindowsViews/Conceptual/ViewPG_iPhoneOS/CreatingViews/CreatingViews.html

尝试增加作为子视图后更改的视图颜色。