问从特定日期启用日期选择器

EN

-(void)findextenddate
{
    NSLog(@"count:%@",adddatetime);
    addatimeclass = adddatetime;
    endnsdate = [addatimeclass objectAtIndex:[addatimeclass count]-1];
    endnsdate1 = (NSDate*) endnsdate; 
    NSLog(@"formatdate:%@",endnsdate1);
}

-(IBAction)clicktoextend:(id)sender
{
    actionsheet = [[UIActionSheet alloc]init];
    actionsheet = [[UIActionSheet alloc] initWithTitle:@"Select Date" delegate:self
                                      cancelButtonTitle:@"Cancel" destructiveButtonTitle:nil otherButtonTitles:@"Select", nil];
    [actionsheet showInView:[self.view superview]];
    [actionsheet setFrame:CGRectMake(0, 117, 320, 383)];
    pickerView = [[UIDatePicker alloc] initWithFrame:CGRectMake(0, 40, 320, 216)];
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss Z"];

    pickerView.minimumDate = endnsdate1 ;
    pickerView.datePickerMode = UIDatePickerModeDate;
    //Add picker to action sheet
    [actionsheet addSubview:pickerView];
    subviews = [actionsheet subviews];


    [[subviews objectAtIndex:SelectButtonIndex] setFrame:CGRectMake(20, 266, 280, 46)]; 
    [[subviews objectAtIndex:CancelButtonIndex] setFrame:CGRectMake(20, 317, 280, 46)];
    [pickerView release];
    [actionsheet release];
}