How call a method when a UICollectionViewCell is pressed? - xcode

I'm trying to call another UIViewController when a UICollectionViewCell is pressed, but I just can't. Which one of the following method i should use?
-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
}
-(void) collectionView:(UICollectionView *)collectionView performAction:(SEL)action forItemAtIndexPath:(NSIndexPath *)indexPath withSender:(id)sender
{
}

Just link the UICollectionViewCell to a new view controller in storyboard!
You don't need those methods.

In a simple case you may want to use a storyboard and establish a segue from your cell to another viewcontroller. That would work if you want to link every cell to the same view controller class.
If you need to instantiate view controllers of different classes or if you are not using a storyboard then you will use first function you mentioned
-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath

Related

UITableView custom cell not displaying data

Here is the story. I have a simple app in which I use 2 tabs, both of them with UITableView. The first tab/view is called "Favorites" and the second one is called "My Profile." In addition I have a custom UITable cell named "CustomViewCell.xib" with an identifier of the same name. FavoritesViewController is a subclass of UITableViewController and that one is running perfectly. But for the ProfileViewController I am using normal ViewController because I don't want the whole view to be UitableView. To make that possible, I the following to ProfileViewController.h:
#interface ProfileViewController : UIViewController <UITableViewDelegate, UITableViewDataSource>
#property (nonatomic, strong) IBOutlet UITableView *tableView;
then in the viewDidLoad of ProfleViewController.m file I have:
[self.tableView registerNib:[UINib nibWithNibName:#"CustomViewCell" bundle:nil]
forCellReuseIdentifier:#"CustomViewCell"];
The following methods are implemented just as in the other tab that's working:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
return [self.myArray count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
// Here I am customizing the cell and returning it.
}
When i run the app, the cells are the right height, but are empty.
To debug I put a break point right before cellForRowAtIndexPath, and the app runs without an error which it shouldn't. So, the program is not even getting to this method. So, I think that's the reason the cells are empty. Do you guys have any idea what might be causing it to skip this particular method? can you also explain it in simpler terms because I'm newbie, you know?
In you ViewDidLoad method, add this code:
[self.tableView setDelegate:self];
[self.tableView setDataSource:self];
Then check again if the breakpoint works
Have you implemented a UITableViewDataSource? A UITableViewController is the delegate and datasource for the Table View it manages so you can define all those methods in the View Controller itself.
For a UITableView that is a subview of a UIViewController, you need to define the Table View's delegate and datasource.
See here: http://www.aboveground.com/tutorials/adding-a-uitableview-to-a-custom-uiview

Added a tableview in a viewcontroller. How do I load tableview cells

I have a view controller
In storyboard, added tableview to view controller.
Created an IBOutlet for tableview to View controller's header file.
The view controller's header file includes an resultsarray
Changed the #interface to include delegates UITableViewDelegate, UITableViewDataSource
View controller implementation file has mandatory tableview protocols
(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
The view controller has search button in storyboard and IBAction in view controller header file. On click of search button, results are obtained. How do I load the array and redisplay tableview with results in search method. After I loaded the results in array, I tried [self viewdidload];, hoping the cells will be loaded. But didn't. I thought of calling
[self.detailView cellForRowAtIndexPath:?indexpath], but dontknow what the value of index path is. Appreciate help from guru's to load the UItableviewcell
Thanks
You should use reloadData or reloadSections methods of tableView in order to reload your tableView from data source.
// you fill your array with results here...
// and then call
[tableView reloadData];
This will call cellForRowAtIndexPath: methods for every cell to update its data.
Here is the reference.

view-based NSTableView's views from XIB?

Is it possible to have a separate XIB file for the NSTableCellView of a view-based NSTableView? Maybe with the help of a NSViewController?
Yes, it seems to be possible.
From Apple's documentation:
In order to function, a programmatically implemented view-based table must implement the following:
...
The - (NSView *)tableView:viewForTableColumn:row: method that is defined by the NSTableViewDelegate Protocol. This method both provides the table with the view to display as the cell for the specific column and row, as well as populates that cell with the appropriate data.
This way you can have an object of the class NSView (or any subclass) and give it back, after you properly filled it with data. Where you get this object from, is not of interest. As far as I know, it would be possible to do the following, for example:
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
// Assume you have a XIB called View.xib
[NSBundle loadNibNamed:#"View" owner:self];
// And you have an IBOutlet to your NSTableView (that's view based) called tView
[tView reloadData];
}
- (NSInteger)numberOfRowsInTableView:(NSTableView *)tableView {
return 20;
}
- (NSView *)tableView:(NSTableView *)tableView
viewForTableColumn:(NSTableColumn *)tableColumn
row:(NSInteger)row {
// Assume your class has an IBOutlet called contentOfTableView,
// your class is File's Owner of the View.xib and you connected the outlet.
return contentOfTableView;
}
Hope it works. I just threw it together having a rough idea in mind. Good luck!

Must a custom table view cell be prototype cell instead of static cell?

I have been googling and only seemed to be able to find examples of how to create custom cell as prototype cell.
My question is: Can I create custom table view cell as static cell?
Thanks in advance!
Eve
No, in Storyboard you can edit your cell like you want by dragging objects into your cell.
You just have to make a new class of UITableViewCell and use that one in Storyboard, connect everything up if needed and use the following methods:
#import "YourTableViewCell.h"
- (YourTableViewCell *)tableView:(YourTableViewCell *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
....
[self configureCell:cell atIndexPath:indexPath];
}
- (void)configureCell:(YourTableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath

Xcode 4.2 iOS 5 : Multiple segues from a UITableView

I'm starting now with Xcode on 4.2 for iOS5 and there are a few changes and I'm now crossing a problem that I can't figure out a way to solve it.
I'm doing an example with a UITablwView that is populated programmatically with 2 Sections, 1st section with only 1 Row, and 2nd Section with 3 Rows.
My aim is to select a row from the table, and based on that row, the user will be redirected to different Views.
For example:
selecting section 0 row 0, app pushes to view 1 - name setting //
selecting section 1 row 0, app pushes to view 3 - address setting
The old fashion way, this is quite simple, just needed to init a UIViewController with initWithNibName and then push the view.
Now with the storyBoard everything changes, or at least I think it changes because I can't see how to get the same result since I can't set multiple segue's from the tableView to different UIViewControllers...and to do the old fashion way I can't see where I can get the NIB names from the views on the storyBoard to init an UIViewController to push.
Does any one knows how to get to this result??
Define two "generic" segues (identified as "segue1" and "segue2", for example) in the storyboard from your source view controller, one to each destination view controller. These segues won't be associated with any action.
Then, conditionally perform the segues in your UITableViewDelegate:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// Conditionally perform segues, here is an example:
if (indexPath.row == 0)
{
[self performSegueWithIdentifier:#"segue1" sender:self];
}
else
{
[self performSegueWithIdentifier:#"segue2" sender:self];
}
}
I have the same problem as you do. The problem is that you can't link your tableViewCell to multiple view controllers. However you can link your source view itself to multiple view controllers.
Control-drag the master view controller (instead of table view cell) from the scene viewer to whatever view controller you want to link. You can do this as much as you want. Notice that the segue shown in source view controller scene should be something like "Push Segue from Root View Controller ..." instead of "Push Segue from NavCell to ...".
Identify each segue link a unique name like "toDetailView1"
Finally, custom the selection in your source view controllers:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if (indexPath.row % 2 == 1) {
[self performSegueWithIdentifier:#"toDetailView1" sender:self];
} else {
[self performSegueWithIdentifier:#"toDetailView2" sender:self];
}
}
Like #陳仁乾 and #Marco explained was completely correct. To make everything a little bit easier I would recommend you to use a single NSArray which will be initialized when viewDidLoad. Just name the segues the same as your UIViewControllers, this way you can Display a correct description of what UIViewControllers you can choose from and you can also perform the segues from this NSArray:
(Actually I'm not sure if it can cause any problems calling the segue the same as the UIViewController you want to call. Please let me know if this is BadPractise)
viewDidLoad
- (void)viewDidLoad
{
[super viewDidLoad];
_arraySessions = [[NSArray alloc] initWithObjects:
#"MyViewControllerName", nil];
}
cellForRowAtIndexPath
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath{
UITableViewCell *cell =
[tableView dequeueReusableCellWithIdentifier:#"overviewCell"
forIndexPath:indexPath];
[cell.textLabel setText:_arraySessions[indexPath.row]];
return cell;
}
didSelectRowAtIndexPath
- (void)tableView:(UITableView *)tableView
didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
[self performSegueWithIdentifier:_arraySessions[indexPath.row]
sender:self];
}

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