ios让navigationItem的UIBarButtonItem的背景色不为蓝色，现实图片本身颜色

UIImage *rightImage = [[UIImage imageNamed:@"add"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]; UIBarButtonItem *barBtn1=[[UIBarButtonItem alloc] initWithImage:rightImage style:UIBarButtonItemStylePlain target:self action:@selector(changeColor)]; 方法就是在初始化图片时，将图片的渲染模式设置为 imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal

最后效果如下