Question

I want to use two tableviews under the segmentedcontrol. one is plain styled and the other is groupstyled. How can i controll the delegate and datasource for the two table views?

—
Regards,
Syed yusuf

Answer 1

Since you can’t change the UITableViewStyle of a UITableView once created (it can only be set at construction time), you have to have two different instances. You can do this in very different ways, but I’ve done it this way: add a UISegmentedControl to your interface, and set its target to the RootViewController class instance in your application. The RootViewController class could look like this:

@class DataSource;

@interface RootViewController : UITableViewController 
{
@private
    UITableView *_originalTableView;
    UITableView *_secondaryTableView;
    DataSource *_dataSource;
    BOOL _showingSecondaryTableView;
}

- (IBAction)swap:(id)sender;

@end

And this might be the implementation:

#import "RootViewController.h"
#import "DataSource.h"

@implementation RootViewController

- (void)dealloc 
{
    [_dataSource release];
    [_originalTableView release];
    [_secondaryTableView release];
    [super dealloc];
}

- (void)viewDidLoad 
{
    [super viewDidLoad];

    _dataSource = [[DataSource alloc] init];

    _secondaryTableView = [[UITableView alloc] initWithFrame:self.tableView.frame 
                                                       style:UITableViewStyleGrouped];
    _secondaryTableView.delegate = _dataSource;
    _secondaryTableView.dataSource = _dataSource;

    _originalTableView = [self.tableView retain];

    _showingSecondaryTableView = NO;
}

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

#pragma mark -
#pragma mark IBAction method

- (IBAction)swap:(id)sender
{
    if (_showingSecondaryTableView)
    {
        self.tableView = _originalTableView;
        _showingSecondaryTableView = NO;
    }
    else
    {
        self.tableView = _secondaryTableView;
        _showingSecondaryTableView = YES;
    }
}

#pragma mark -
#pragma mark Table view methods

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

- (NSInteger)tableView:(UITableView *)tableView 
 numberOfRowsInSection:(NSInteger)section 
{
    return 5;
}

- (UITableViewCell *)tableView:(UITableView *)tableView 
         cellForRowAtIndexPath:(NSIndexPath *)indexPath 
{

    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) 
    {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault 
                                       reuseIdentifier:CellIdentifier] autorelease];
    }

    cell.textLabel.text = [NSString stringWithFormat:@"RootViewController cell %d", indexPath.row];
    return cell;
}

@end

This is the interface of the DataSource class:

#import <UIKit/UIKit.h>

@interface DataSource : NSObject <UITableViewDelegate, 
                                  UITableViewDataSource>
{
}

@end

And the implementation:

#import "DataSource.h"

@implementation DataSource

#pragma mark -
#pragma mark Table view methods

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView 
{
    return 2;
}

- (NSInteger)tableView:(UITableView *)tableView 
 numberOfRowsInSection:(NSInteger)section 
{
    return 3;
}

- (UITableViewCell *)tableView:(UITableView *)tableView 
         cellForRowAtIndexPath:(NSIndexPath *)indexPath 
{

    static NSString *CellIdentifier = @"DataSourceCell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) 
    {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault 
                                       reuseIdentifier:CellIdentifier] autorelease];
    }

    cell.textLabel.text = [NSString stringWithFormat:@"DataSource cell %d", indexPath.row];
    return cell;
}

@end

You can change the datasource and delegate of the UITableView instances to anything you want, at any time during runtime, which might help you encapsulate different data sources with separate controllers.

Hope this helps!