uibutton 设置圆角边框
[m_selectUserBtr.layer setMasksToBounds:YES];
[m_selectUserBtr.layer setCornerRadius:3]; //设置矩形四个圆角半径
[m_selectUserBtr.layer setBorderWidth:1.0]; //边框宽度
UIColor *ccc = [UIColor colorWithRed:1.00 green:1.00 blue:1.00 alpha:.35];
CGColorRef colorref = [ccc CGColor];
[m_selectUserBtr.layer setBorderColor:colorref];//边框颜色