IOS 改变按钮标题位置和缩进

UIButton *missGesturebtn = [UIButton buttonWithType:UIButtonTypeCustom];
missGesturebtn.frame = CGRectMake(0, CGRectGetMaxY(_editGesturebtn.frame)+20, SCREEN_WIDTH, 40);
[missGesturebtn setTitle:@"忘记手势密码" forState:UIControlStateNormal];
[missGesturebtn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
missGesturebtn.backgroundColor = [UIColor whiteColor];
missGesturebtn.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;//左对齐
missGesturebtn.titleEdgeInsets = UIEdgeInsetsMake(0, 20, 0, 0);//上，左，下，右
[missGesturebtn addTarget:self action:@selector(missGesture) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:missGesturebtn];