此处是切换明文、暗文的方法
- (void)eyebtnClick:(UIButton *)btn{
NSString *passStr = _passwordTextF.text;//切换的时候记录之前的密码
_passwordTextF.text = @"";
_passwordTextF.text = passStr;//切换完成赋值
//查看密码btn
btn.selected = !btn.selected;
_passwordTextF.secureTextEntry = ! _passwordTextF.secureTextEntry;}
- (void)eyebtnClick:(UIBut
