Custom buttons prevent repeated submission

Due to network speed problems, users can't wait to click the submit button multiple times, resulting in multiple submissions. You can use the Custom button control to solve this problem.

Principle: Click the button and set its disabled attribute to true.

Custom button control coreCode:

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01	Protected Override Void Addattributestorender (htmltextwriter writer)

02

{

03	System. Text. stringbuilder clientsideeventreference =New System. Text. stringbuilder ();

04

05	// Whether to implement page Verification

06	If (((This. Page! =Null)&&This. Causesvalidation )&&(This. Page. validators. Count> 0 ))

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{

08	Clientsideeventreference. append ("If (typeof (page_clientvalidate) = 'function') {If (page_clientvalidate () = false) {return false ;}}");

09

}

10

11	// Prompt for submission

12	If (This. Showmessagebox)

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{

14	Clientsideeventreference. append ("If (! Confirm ('" +This. Warningtext +"') {Return false }");

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}

16

17	// Whether to use the onclientclick attribute of the button for JS Verification

18	If (This. Onclientclick! ="")

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{

20	Clientsideeventreference. append ("If (! "+ Onclientclick +") {Return false ;}");

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}

22

23	Clientsideeventreference. appendformat ("This. value = '{0 }';",(String)This. Viewstate ["Aftersubmittext"]);

24	Clientsideeventreference. append ("This. Disabled = true ;");

25

26

27	Clientsideeventreference. append (This. Page. clientscript. getpostbackeventreference (This,String. Empty ));

28

29	Writer. addattribute (htmltextwriterattribute. onclick, clientsideeventreference. tostring (),True);

30	Base. Addattributestorender (writer );

31

}

 Use the Custom button sample core code:

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01	<Pre Class=Brush: CSHARP> <Script Type="Text/JavaScript">

02	Function validate ()

03

{

04	VaR TXT = Document. getelementbyid ('<% = txtcontext. clientid %> ');

05	If (txt. value = "")

06

{

07	Alert ('text box cannot be blank! ');

08	TXT. Focus ();

09	Return false;

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}

11

12	Return true;

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}

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</Script>

15	cc1: clickoncebutton id = " btnadd " runat = "server" text = "Submit" onclick = "btnadd_click" onclientclick = " Validate () " />

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</Pre>

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<Strong> Notes </Strong>: If you set the onclientclick attribute for verification, the attribute value corresponding to the onclientclick attribute is: JS functions cannot carry the symbol ";" <BR> Example: incorrect syntax: onclientclick = "Validate ();" Correct syntax: onclientclick = "Validate ()"

Weaknesses in the US: The source code of the page shows two onclick events (as shown below). The onclick event corresponding to the onclientclick attribute does not play a role. Hope that the experts who pass by will give a solution!

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1	<Input onclick ="If (! Validate () {return false;} This. value = 'submitting. Please wait... '; this. disabled = true ;__ dopostback ('btnadd ','')" Type ="Submit" Name ="Btnadd" Value ="Submit" Onclick ="Validate ();" Id ="Btnadd" />

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