iphone开发 UIAlertView+ UIPickerView

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"请选择城市"
message:@"\n\n\n\n\n\n\n\n"
delegate:self
cancelButtonTitle:@"取消"
otherButtonTitles:@"确定",nil];

UIPickerView *m_pPickerView=[[UIPickerView alloc] init];
m_pPickerView.showsSelectionIndicator = YES;
m_pPickerView.frame=CGRectMake(20, 45, 240, 150);
m_pPickerView.delegate=self;
[alert addSubview:m_pPickerView];
[alert show];
[alert release];