UITextField里面的text垂直居中以及最右侧放图片

最右侧加图片是以下代码,
UIImageView *imgv=[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"right.png"]];
text.rightView=imgv;
text.rightViewMode = UITextFieldViewModeAlways;
如果是在最左侧加图片就换成:
text.leftView=imgv;
text.leftViewMode = UITextFieldViewModeAlways;

UITextField 继承自 UIControl,此类中有一个属性contentVerticalAlignment
所以想让UITextField里面的text垂直居中可以这样写:
text.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;