Set a background image for the navigationbar and extend it proportionally to display the complete image

//按比例显示图片 
UIImage *backGroundImage = [UIImage imageNamed:@"titleImage"]; 
backGroundImage = [backGroundImage resizableImageWithCapInsets:UIEdgeInsetsZero resizingMode:UIImageResizingModeStretch]; 
[self.navigationController.navigationBar setBackgroundImage:backGroundImage forBarMetrics:UIBarMetricsDefault];

 

 

Pro-test so good.