iOS 创建背景透明或含有自定义图片的UIToolbar

//使button的tint色与导航条一致
toolbar.tintColor = self.navigationController.navigationBar.tintColor;
toolbar.backgroundColor = [UIColor clearColor];  //设置为背景透明
for (UIView *view in [rightToolbar subviews]) {
 if ([view isKindOfClass:[UIImageView class]]) {
  [view removeFromSuperview];
 }
}

//MyToolbar.h
@interface MyToolbar : UIToolbar
 
@end
 
//MyToolbar.m
@implementation MyToolbar
 
- (id)initWithFrame:(CGRect)aRect {
    if ((self = [super initWithFrame:aRect])) {
        self.opaque = NO;
        self.backgroundColor = [UIColor clearColor];  //设置为背景透明，可以在这里设置背景图片
        //self.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"background"]]; 
        self.clearsContextBeforeDrawing = YES;
    }
    return self;
}
 
- (void)drawRect:(CGRect)rect {
    // do nothing
}
 
@end