thinkphp自带验证码全面解析

<div style="position:absolute;z-index:3;top:160px;left:180px;">
<img style="cursor:pointer; " src="{:u('verify')}" onclick="this.src=this.src+'?'+math.random()" id="safecode" style="height:50px;width:70%;"/>
</div> 
//验证码判断
public function verify(){
ob_clean();
//显示验证码
$cfg=array(
'codeset' => '0123456789', // 验证码字符集合
'imageh' => 25, // 验证码图片高度
'imagew' => 80, // 验证码图片宽度
'length' => 4, // 验证码位数
'fontttf' => '4.ttf', // 验证码字体，不设置随机获取
'fontsize' => 10, // 验证码字体大小(px)
'usenoise' => false, // 是否添加杂点
'usecurve' => false, // 是否画混淆曲线
'bg' => array(226,229,236) //背景颜色
);
$very=new \think\verify($cfg);
$very->entry();
} 
//客户端通过ajax，实现校验验证码
public function checkverify(){
$code = i('get.code');
$very = new \think\verify();
$key = $this->auth_my_code($very,$very->sekey);
// 验证码不能为空
$secode = session($key);
//对$code进行加密，在比较校验
if($this->auth_my_code($very,strtoupper($code)) == $secode['verify_code']) {
echo json_encode(array('flag'=>1,'cont'=>'验证码正确'));
}else{
echo json_encode(array('flag'=>2,'cont'=>'验证码错误'));
}
}
private function auth_my_code($vry,$str){
$key = substr(md5($vry->sekey), 5, 8);
$str = substr(md5($str), 8, 10);
return md5($key . $str);
}

else{
$('#safecode').attr("src","/login/verify?"+math.random());
newalert(2,"验证码有误，请重新输入",null);
code_ok = false;
$('#verifyresult').html(msg.cont).css({'color':'red','font-size':'12px'}); 
}

<script type="text/javascript">
$("#login_btn").click(function(){
var username = $.trim($("#username").val());
var password = $.trim($("#password").val());
var code = $('#veri').val();
if(username == ""){
newalert(2,"请输入用户名",null);
shutdown();
return false;
}else if(password == ""){
newalert(2,"请输入密码",null);
shutdown();
return false;
}else if(code==''){
newalert(2,"请输入验证码",null);
return false;
}
//ajax去服务器端校验
$.ajax({
url:"__controller__/checkverify",
data:{'code':code},
datatype:'json',
success:function(msg){
if(msg.flag==1){
var data= {
username:username,
password:password
};
$.ajax({
type:"post",
url:"{:u('login/login')}",
data:data,
datatype:"json",
success:function(msg){
if(msg.respcode=='000'){
shutdown();
if(msg.org_code=='fcb'){
location.href="/invest/index?biao_type=cwb";
}else{
location.href="{$think.config.vip_url}/individual/index";
}
}else{
newalert(2,msg.respdesc,null);
return false;
}
},
error:function(){
shutdown();
},
beforesend: function() {
loading();
},
});
}else{
$('#safecode').attr("src","/login/verify?"+math.random());
newalert(2,"验证码有误，请重新输入",null);
code_ok = false;
$('#verifyresult').html(msg.cont).css({'color':'red','font-size':'12px'}); 
}
}
});
}); 
</script>