在XIB文件中设置好toolbar 以及flexible space button
NSMutableArray *toolbarIems = [toolbar.items mutableCopy];
// [editItems removeObject:sortBarButtonItem]; //Sort function postpone
[toolbarIems removeObject:editBarButtonItem];
if ([toolbarIems count] >= 3)
{
[toolbarIems insertObject:deleteBarButtonItem atIndex:3];
}
[toolbarIems insertObject:cancelBarButtonItem atIndex:0];
[toolbar setItems:toolbarIems animated:NO] ;