<?

php

session_start

();

/*

*

     * 检查表单是否被重复提交

     * 相同内容的表单在设定时间内只能提交1次

     * @param int $iTimeOffset

     * @return bool

     

*/

function

 checkFormSubmit(

$iTimeOffset

=

60

){

    

//

 取得表单的标识

    

$idForm

 

=

 

md5

(

serialize

(

$_POST

));

    

//

 是否需要表单提交检察

    

$iFormCheck

 

=

 

true

;

    

if

 (

isset

(

$_SESSION

[

'

formSubmitCheck

'

])){

        

//

 删除过期的表单标识

        

foreach

 (

array_keys

(

$_SESSION

[

'

formSubmitCheck

'

]) 

as

 

$val

){

            

if

 (

time

() 

>

 

$val

){

                

unset

(

$_SESSION

[

'

formSubmitCheck

'

][

$val

]);

            }

        }

    }

else

 {

        

$_SESSION

[

'

formSubmitCheck

'

] 

=

 

array

();

        

$iFormCheck

 

=

 

false

;

    }

    

if

 (

$iFormCheck

 

==

 

true

){

        

//

 检查是否有重复标识的提交记录

        

foreach

 (

$_SESSION

[

'

formSubmitCheck

'

] 

as

 

$val

){

            

if

 (

$val

 

==

 

$idForm

){

                

return

 

false

;

            }

        }

    }

    

//

 保存表单标识

    

$_SESSION

[

'

formSubmitCheck

'

][(

time

()

+

$iTimeOffset

)] 

=

 

$idForm

;

    

return

 

true

;

}

if

 (

count

(

$_POST

) 

>

 

0

){

    

if

 (checkFormSubmit()

===

true

){

        

echo

 

'

表单提交成功

'

;

    }

else

 {

        

echo

 

'

表单重复提交

'

;

    }

}

?>

<

form method

=

"

POST

"

>

    

<

input type

=

"

text

"

 name

=

"

a

"

>

    

<

input type

=

"

text

"

 name

=

"

b

"

>

    

<

textarea name

=

"

c

"

></

textarea

>

    

<

input type

=

"

submit

"

 name

=

"

btnSubmit

"

 value

=

"

确认

"

>

</

form

>

<?

php

var_dump

(

$_POST

);

var_dump

(

$_SESSION

);

?>