Not able to Run trigger on custom & Standardobject

Question

I am trying to run the below trigger in a custom object but getting the below error. Please help me

Error: Compile Error: Variable does not exist: ID__C at line 8 column 3

trigger AfterInsert on Status__c (before insert, Before update, after insert) {
    For (Status__c A:Trigger.New){
        A.Phone__c='91'+A.Phone__c;
        Case C=New Case();
        C.Subject='Case Raised';
        C.Priority='Low';
        C.ID__C='A.ID';//error is here
        insert C;
    }
}

Answer 1

trigger AfterInsert on Status__c (After update, After insert) { 
   List<case>caseList = new List<case>(); 
   for (Status__c a:Trigger.New){ 
        a.Phone__c = '91'+a.Phone__c; 
        Case c = New Case(); 
        c.Subject = 'Case Raised'; 
        c.Priority = 'Low'; 
        c.ID__ C= a.ID; 
        caseList.add(c);
     }
   insert caseList; 
}

You cannot have access to the IDs in before trigger. This trigger should work on after clause. Treating the ID__c as a lookup field to Status__c object i have edited your code.Also inserting in a loop is not a good practice. While a bulk operation your code will fail. Please try it and let me know it it works out for you or not.