為UIAlertView添加block支持
這里推薦一個開源的實現: https://github.com/jivadevoe/UIAlertView-Blocks
[[[UIAlertView alloc]initWithTitle:@"溫馨提示" message:@"請?zhí)顚懶畔? cancelButtonItem:[RIButtonItem itemWithLabel:@"取消" action:^{
}] otherButtonItems:[RIButtonItem itemWithLabel:@"確定" action:^{
}], nil] show];
