TableView和Detail视图单元格显示

Question

I'm learning how to make a contact using TableView and navigation controller. I have done the first view page with some cells, but I have some problem with showing the cells on the detail view page of each cell from first view. when tap the Group A, Group B, Group C on first view page, it goes to the detail view of each cell, it should show cells named A1 A2 A3, B1 B2 B3 or C1 C2 C3 according to my code on detail view page. but it display nothing. Hope someone can give me some advises, thank you so much!

FirstViewController.m

@implementation FirstViewController
-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{
    return 1;
}

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSections(NSInteger)section{

    return [self.contactArray count];
}

-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
    static NSString *Celldentifier = @"cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:Celldentifier];

if (cell == NULL) {
    cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:Celldentifier];

}
cell.textLabel.text = [self.contactArray objectAtIndex:indexPath.row];
return cell;

}

-(void)tableView: (UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

    self.myTableView = [self.contactArray objectAtIndex:indexPath.row];
    [self performSegueWithIdentifier:@"To Second View Segue" sender:self];     
}


-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
    if([segue.identifier isEqualToString:@"To the second view"]){
        NSIndexPath *indexpath = [self.myTableView indexPathForSelectedRow];
        self.contactArray = [self.contactArray objectAtIndex:indexpath.row];
        SecondViewController *vc = segue.destinationViewController;
        vc.memberName = [self.contactArray objectAtIndex:indexpath.row];
        vc.title = vc.memberName;

    }
}

- (void)viewDidLoad {
    [super viewDidLoad];
    self.contactArray = [[NSMutableArray alloc]initWithObjects:@"Group A",@"Group B",@"Group C", nil];

}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
 }

@end

SecondViewController.m

@implementation SecondViewController{

NSArray *groupA;
NSArray *groupB;
NSArray *groupC;

}

-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{
    return 1;
}

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{

    if([self.memberName isEqualToString:@"groupA"]){
        return [groupA count];
    }
    else if([self.memberName isEqualToString:@"groupB"]){
        return [groupB count];
    }
    else if([self.memberName isEqualToString:@"groupC"]){
        return [groupC count];
    }
    return 0;
}

-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
    static NSString *Celldentifier = @"cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:Celldentifier];

    if (cell == NULL) {
        cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:Celldentifier];

    }
    if([self.memberName isEqualToString:@"groupA"]){
        cell.textLabel.text = [groupA objectAtIndex:indexPath.row];
    }
    if([self.memberName isEqualToString:@"groupB"]){
        cell.textLabel.text = [groupB objectAtIndex:indexPath.row];
    }
    if([self.memberName isEqualToString:@"groupC"]){
        cell.textLabel.text = [groupC objectAtIndex:indexPath.row];
    }

    return cell;

}

- (void)viewDidLoad {
    [super viewDidLoad];
    groupA = [NSArray arrayWithObjects:@"A1",@"A2",@"A3",nil];
    groupB = [NSArray arrayWithObjects:@"B1",@"B2",@"B3",nil];
    groupC = [NSArray arrayWithObjects:@"C1",@"C2",@"C3",nil];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
}

@end

first view

detail view but nothing displayed

Answer 1

Have you set the delegate and datasource of tableview?

If Yes, check if the datasource methods (numberOfRowsInSection:) are called after you do

groupA = [NSArray arrayWithObjects:@"A1",@"A2",@"A3",nil]; in viewDidLoad method.