从一个界面push到下一界面左上角返回按钮文字设置（常用功能）

//在父viewController中如下设置：

    UIBarButtonItem *backbutton = [[UIBarButtonItem alloc]init];

    backbutton.title = @"返回列表";

    self.navigationItem.backBarButtonItem = backbutton;

    [backbutton release];
//navigationbar的back键触发其他事件

UIButton *back =[[UIButton alloc] initWithFrame:CGRectMake(200, 25, 63, 30)]; 

[back addTarget:self action:@selector(reloadRowData:) forControlEvents:UIControlEventTouchUpInside];

[back setImage:[UIImage imageNamed:@"返回按钮.png"] forState:UIControlStateNormal];

UIBarButtonItem *backButtonItem = [[UIBarButtonItem alloc] initWithCustomView:back];

self.navigationItem.leftBarButtonItem = loginButtonItem

[back release];

[backButtonItem release];