title: An error about Android cursor and listView
body: <p>I want to add a number in all listView, these numbers come from the SQLite. I use a for loop to add them, and I use a cursor to get them. The question is when I delete one of them, except the last one, the for loop can't work. I found that there is a function "isNull" for cursor, I want to use it, but it doesn't work.</p>
  
  <pre><code>    int itemNum=doListlist.getCount();
          for(int i = 0; i &lt; itemNum; i++){
              if(cursor.isNull(i+1)==false){
                  float num=Float.parseFloat(listsDbAdapter.fetchData(tableName, i+1).getString(3));
                  float price=Float.parseFloat(listsDbAdapter.fetchData(tableName, i+1).getString(5));
                  total+=num*price;
              }
              else {
              itemNum++;
              }
          }    
  </code></pre>
  
  <p>If you know the reason why it always error, please tell me, THANKYOU!!!</p>