如何使导航栏按钮项显示我的自定义图像？

Question

How do I make navigation bar button item show my custom image as is? Using the code below my button shows up as a solid color. The outline of the image shows up correctly.

UIImage *image = [UIImage imageNamed:@"image.png"];
UIBarButtonItem *buttonItem = [[UIBarButtonItem alloc] initWithImage:image style:UIBarButtonItemStylePlain target:self action:@selector(onButtonTapped:)];

self.navigationItem.leftBarButtonItem = buttonItem;

Answer 1

If you are on iOS7 try to change the UIImage's rendering mode

UIImage *image = [UIImage imageNamed:@"image.png"];
UIImage *newImage = [image imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];

use newImage to init the bar button item