在网络上完的时候，看倒了一个好的文章，刚好是自己感兴趣的
方法如下
CGRect frame = CGRectMake(0,0,320,49);
UIView *v = [UIView alloc]initWithFrame:frame];
UIImage *img = [UIImage imageNamed:@"tabbar.png"];
UIColor *c =[ [UIColor alloc]initWithPatterImage:img];
v.backgroundColor = c;
[m_TabbBar.tabBar insertSubView v atIndex:0];
m_TabBar.tabBar.opaque = YES;
[c release];
[v release];
原文地址：http://www.ieliwb.com/thanks-cocoachina-ru-developers/
其它的实现方式，也可以参考下：
http://www.cocoachina.com/bbs/read.php?tid-59827.html
http://www.cocoachina.com/bbs/read.php?tid-59653.html