UIButton *roundBtn = [UIButton buttonWithType:UIButtonTypeCustom];
roundBtn.frame = CGRectMake(100, 100, 50, 50);
roundBtn.backgroundColor = [UIColor redColor
//設置cornerRadius
_roundBtn.layer.cornerRadius = 10.0;
UIButton *roundBtn = [UIButton buttonWithType:UIButtonTypeCustom];
roundBtn.frame = CGRectMake(100, 100, 50, 50);
roundBtn.backgroundColor = [UIColor redColor
//設置cornerRadius
_roundBtn.layer.cornerRadius = 10.0;