iOS8 UIAlertController弹出框中添加视图（例如日期选择器等等）
UIDatePicker *datePicker = [[UIDatePicker alloc] init]; datePicker.datePickerMode = UIDatePickerModeDate;
UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"\n\n\n\n\n\n\n\n\n\n\n\n" message:nil preferredStyle:UIAlertControllerStyleActionSheet];
[alert.view addSubview:datePicker];
UIAlertAction *ok = [UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
NSDateFormatter* dateFormat = [[NSDateFormatter alloc] init];
//实例化一个NSDateFormatter对象
[dateFormat setDateFormat:@"yyyy-MM-dd"];//设定时间格式
NSString *dateString = [dateFormat stringFromDate:datePicker.date];
//求出当天的时间字符串
NSLog(@"%@",dateString);
}];
UIAlertAction *cancel = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
}];
[alert addAction:ok];
[alert addAction:cancel];
[self presentViewController:alert animated:YES completion:^{ }];
