设置item背景图片

  if(iOS7) {
           
            item = [item initWithTitle:title[i]
           image:[unSelectImageimageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]
           selectedImage:[selectImageimageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];
           
        }else{
           
            [item setFinishedSelectedImage:selectImagewithFinishedUnselectedImage:unSelectImage];
            item.title= title[i];
        }