弹出自定义显示大小的UIViewController

 EditHeadViewController *editHead = [[[EditHeadViewController alloc] init] autorelease];

     //设置待显示控制器的范围
     [editHead.view setFrame:CGRectMake(0, 0, 173, 108)];

     //设置待显示控制器视图的尺寸
     editHead.contentSizeForViewInPopover = CGSizeMake(173, 108);

     UIPopoverController *popover = [[UIPopoverController alloc] initWithContentViewController:editHead];

     self.editPopoverController = popover;

     //设置弹出窗口尺寸
     self.editPopoverController.popoverContentSize = CGSizeMake(173, 108);

     [self.editPopoverController presentPopoverFromRect:CGRectMake(0, 200, 173, 108) inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];

     [popover release];