self.returnBtn= [[UIButtonalloc]initWithFrame:CGRectMake(0,0,200,25)];
[self.returnBtnsetImage:[UIImageimageNamed:@"nav_bar_back_white_icon@2x"]forState:UIControlStateNormal];
self.returnBtn.contentHorizontalAlignment=UIControlContentHorizontalAlignmentLeft;
[self.returnBtnsetTitle:@"购物车"forState:UIControlStateNormal];
[self.returnBtnsetContentEdgeInsets:UIEdgeInsetsMake(0, -12,0,0)];
[self.returnBtnsetImageEdgeInsets:UIEdgeInsetsMake(-5,0, -5,0)];
[self.returnBtnsizeToFit];
self.returnBtn.frame=CGRectMake(0,0,self.returnBtn.bounds.size.width,25);
[self.returnBtnaddTarget:selfaction:@selector(doBack:)forControlEvents:UIControlEventTouchDown];
UIBarButtonItem*btn = [[UIBarButtonItemalloc]initWithCustomView:self.returnBtn];
self.navigationItem.leftBarButtonItem= btn;
