A very good framwork for showing message on the status bar.
[WYStatusBarHUD showSuccess:@"登录成功!"];
[WYStatusBarHUD showError:@"登录失败!"];
[WYStatusBarHUD showText:@"我是自定义文字"];
[WYStatusBarHUD showText:@"自定义文字" imageName:@"test"];
[WYStatusBarHUD showLoading:@"正在登录中..."];
[WYStatusBarHUD hide];