Question

I am currently writing my first iPhone app, but have encountered an issue. I have a view which contains a UITableView. This is the first time that I have attempted this, and this is the behaviour that I am trying to achieve:

When the user selects one of the rows, I would like this to call a new view, taking the user to a different page displaying info in reference to what they have selected.

I have it currently, so when the user selects a row it displays a UIAlert in the same view, but this doesn;t suit my needs. I have set the UITableView up through interface builder, and inputted the following code into my .m file to set it up.

- (NSInteger)tableView:(UITableView *)tableView 
 numberOfRowsInSection:(NSInteger)section {
    //return the value
    return 10;
}

//now we define the cells.
- (UITableViewCell *)tableView:(UITableView *)tableView 
         cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    // Identifier for retrieving reusable cells.
    static NSString *cellIdentifier = @"MyCellIdentifier";

    // Attempt to request the reusable cell.
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];

    // No cell available - create one
    if(cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault 
                                      reuseIdentifier:cellIdentifier];
    }

    // Set the text of the cell to the row index.
    cell.textLabel.text = [NSString stringWithFormat:@"iPad %d", indexPath.row];

    return cell;
}

This creates a list of ten rows. The following codes gives me my UIAlert when tapped, however, I want to remove this and make it call a new view of my choice;

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

    // Show an alert with the index selected.
    UIAlertView *alert = [[UIAlertView alloc] 
                          initWithTitle:@"iPad Selected"                         
                          message:[NSString stringWithFormat:@"iPad %d", indexPath.row]                     
                          delegate:self       
                          cancelButtonTitle:@"OK"           
                          otherButtonTitles:nil];
    [alert show];
    [alert release];   

}

Can anyone help with this last piece of code? the view I want it to call is called ‘ProteinView’.

Answer 1

Alrighty, what we need to do is use one of the UITableView methods that are already readily available to us. We’ll do the following.

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

ProteinView *detailViewController = [[ProteinView alloc] initWithNibName:@"ProteinView" bundle:nil];

        // It is here we'd pass information from the currently selected UITableViewCell to the ProteinView.
        // An example of this is the following.

        // I would do it like this, but others would differ slightly.
        NSString *titleString = [[[NSString alloc] initWithFormat:@"iPad %d",indexPath.row] autorelease];

        // title is an object of detailViewController (ProteinView). In my own instances, I have always made a NSString which in viewDiDLoad is made the self.navigationBar.title string. Look below for what my ProteinView.m and .h would look like.
        detailViewController.stringTitle = titleString;
        // ...
        // Pass the selected object to the new view controller.
        [self.navigationController pushViewController:detailViewController animated:YES];
        [detailViewController release];
}

EDIT

// -------- ProteinView.m -------- //

- (void)viewDidLoad {

[super viewDidLoad];
// Do any additional setup after loading the view from its nib.

// Here we set the navigationItem.title to the stringTitle. stringTitle is declared in the .h. Think of it as a global scope variable. It is also propertised in the .h and then synthesized in the .m of ProteinView. 
self.navigationItem.title = stringTitle;
}

I haven’t compiled this, so I don’t know if it’ll fully work. But that is definitely the fastest and most easiest way to do it!