No. Auckland is not a dangerous city on a worldwide comparison at all. In fact it regularly features in the top 10 most livable cities, one of the metrics included in this ranking is crime rate.

Global Liveability Ranking 2016 (You have to register but you can download the entire report for free if you like)

Auckland is a big city and has big city crime issues, but nothing unusual. Articles about crime in Auckland might be more prevalent because it is an outlier compared to NZ as a whole.

Most major cities in Europe would have a much higher crime rate than Auckland.

Of course, my advice is to never be worried about crime, but always be prepared for it. Use common sense and you'd be extremely unlucky to find yourself a victim.