I'm getting error because i'm using getcontent() method in trigger, is there any other way to solve??
My code:
trigger Send_PDF_to_SharePoint on QNews__c (after insert, after update) {
    for(QNews__c qn: Trigger.new)
    {
        Messaging.SingleEmailMessage email = new Messaging.SingleEmailMessage();
        // Reference the attachment page and pass in the ID
        if(qn.Article_Type__c=='Multi_Topic__kav'){
            PageReference pdf =  Page.Multi_Topic_PDF;
            pdf.getParameters().put('id',(String)qn.Article_ID__c); 
            pdf.setRedirect(true);
            system.debug('================10========'+qn.Article_Title__c+'========='+qn.Article_ID__c);
            system.debug('================11==========='+pdf);
        // Take the PDF content
        Blob b = pdf.getContent();//line 13

        // Create the email attachment
        Messaging.EmailFileAttachment efa = new Messaging.EmailFileAttachment();
        efa.setBody(b);
        efa.setContentType('application/pdf');
        efa.setFileName(qn.Article_Title__c+'_'+qn.Article_Version_Number__c+'.pdf');
        
        String body='This attachment is the PDF copy of Article:'+qn.Article_Title__c+'with version number'+qn.Article_Version_Number__c;    
        String[] toAddresses = new String[]{'vijaku@vsp.com'};
        email.setToAddresses(toAddresses);
        email.setSubject(qn.Data_Category__c);
        email.setPlainTextBody( body );
        email.setFileAttachments(new Messaging.EmailFileAttachment[] {efa});
        Messaging.SendEmailResult [] r = Messaging.sendEmail(new Messaging.SingleEmailMessage[] {email});           
       } 
    }
       
}