1.自定义按钮

//左按钮

        UIButton *leftBtn = [[UIButtonalloc]initWithFrame:RectWithPara(-20,0, 44, 44)];

        [leftBtn addTarget:selfaction:@selector(btnClicked:)forControlEvents:UIControlEventTouchUpInside];//设置按钮点击事件

       [leftBtn setBackgroundImage:ImageNamed(@"ic_fanhui_normal.png")forState:UIControlStateNormal ];//设置按钮正常状态图片

        [leftBtn setBackgroundImage:ImageNamed(@"ic_fanhui_pressed.png")forState:UIControlStateSelected];//设置按钮选中图片

2.初始化UIBarButtonItem

        UIBarButtonItem *leftBarButon = [[UIBarButtonItemalloc]initWithCustomView:leftBtn];

        // 调整 leftBarButtonItem 在 iOS7下面的位置

        if(([[[UIDevicecurrentDevice] systemVersion]floatValue]>=7.0?20:0))

        {

            UIBarButtonItem *negativeSpacer = [[UIBarButtonItemalloc]initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace

                target:nilaction:nil];

              negativeSpacer.width = -20;//这个数值可以根据情况自由变化

            self.navigationItem.leftBarButtonItems =@[negativeSpacer, leftBarButon];

        }else

            self.navigationItem.leftBarButtonItem = leftBarButon;

解决ios7.0 以后自定义导航栏左边按钮靠右的问题