jQuery Datatables：iDisplayLength设置为-1以显示所有行

I use jQuery Datatables and want to listen a Table with all my entries via ajax from a server. Everything works perfectly. I mean, i get the data and can show them in the table. I got only one problem. I want to show all rows/entries at once. I've googled and all say, that i just have to set the iDisplayLength to -1. But if I do that, i got only 1 entrie/row(Showing 1 of 1 of totally 50 entries). Any idea what i'm doing wrong? This is my code to initialize the table:I use jQuery Datatables and want to listen a Ta