I am programmatically creating a tableview in objective c. How can I make the cells static programmatically?
Thanks
Making cells static programmatically doesn't really make sense. Static cells are basically only for Interface Builder and requires the entire TableView to be static. They allow you to drag UILables, UITextFields, UIImageViews, etc. right into cells and have it show up just how it looks in Xcode when the app is run.
However, your cells can be "static" programmatically by not using an outside data source and hardcoding everything, which is usually going to be kind of messy and generally a poor idea.
I suggest making a new UITableViewController with a .xib and customizing it from there if you want "static" cells. Otherwise, just hardcode all your values and it's basically the same thing, but is probably poor design if it can be avoided.
By using a distinct cell identifier for each one you will get it. You could use something like this:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *cellIdentifier = [NSString stringWithFormat:#"s%i-r%i", indexPath.section, indexPath.row];
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell == nil)
{
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier] autorelease];
//you can customize your cell here because it will be used just for one row.
}
return cell;
}
You could also do it the old fashioned and just create the cell the way you want depending on the NSIndexPath, this works with Static Cell TVC's and regular table views (don't forget to return the proper number of sections and rows in their datasource methods):
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
switch indexPath.row {
case 0:
// First cell, setup the way you want
case 1:
// Second cell, setup the way you want
}
// return the customized cell
return cell;
}
I you want to create cells structure for example for a settings screen or something like that and you maybe need just to modify some cells content but not their number or sections structure you can overload method of your UITableViewController subclass like this:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *aCell = [super tableView:tableView cellForRowAtIndexPath:indexPath];
// Configure the cell...
if ([aCell.reuseIdentifier isEqualToString:#"someIdentifier"]){
//some configuration block
}
else if ([aCell.reuseIdentifier isEqualToString:#"someOtherIdentifier"]) {
//other configuration block
}
return aCell;
}
But you can make it in a better way with a little bit more code;
1) In the begining of your .m file add typedef:
typedef void(^IDPCellConfigurationBlock)(UITableViewCell *aCell);
2) add cellConfigurations property to your TablviewControllerSubclass extention:
#interface IPDSettingsTableViewController ()
#property (nonatomic, strong) NSDictionary *cellConfigurations;
#property (nonatomic) id dataModel;
#end
3) Modify your static cells of TableviewController subclass in storyboard or xib
and add unique cellReuseIdentifier for each cell you want to modify programmatically
4) In your viewDidLoad method setup cellsConfiguration blocks:
- (void)viewDidLoad
{
[super viewDidLoad];
[self SetupCellsConfigurationBlocks];
}
- (void)SetupCellsConfigurationBlocks
{
//Store configurations code for each cell reuse identifier
NSMutableDictionary *cellsConfigurationBlocks = [NSMutableDictionary new];
//store cells configurations for a different cells identifiers
cellsConfigurationBlocks[#"someCellIdentifier"] = ^(UITableViewCell *aCell){
aCell.backgroundColor = [UIColor orangeColor];
};
cellsConfigurationBlocks[#"otherCellIdentifier"] = ^(UITableViewCell *aCell){
aCell.imageView.image = [UIImage imageNamed:#"some image name"];
};
//use waek reference to self to avoid memory leaks
__weak typeof (self) weakSelf = self;
cellsConfigurationBlocks[#"nextCellIdentifier"] = ^(UITableViewCell *aCell){
//You can even use your data model to configure cell
aCell.textLabel.textColor = [[weakSelf.dataModel someProperty] isEqual:#YES] ? [UIColor purpleColor] : [UIColor yellowColor];
aCell.textLabel.text = [weakSelf.dataModel someOtherProperty];
};
weakSelf.cellConfigurations = [cellsConfigurationBlocks copy];
}
5) overload tableView:cellForRowAtIndexPath method like this:
#pragma mark - Table view data source
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *aCell = [super tableView:tableView cellForRowAtIndexPath:indexPath];
// configure cell
[self configureCell:aCell withConfigurationBlock:self.cellConfigurations[aCell.reuseIdentifier]];
return aCell;
}
- (void)configureCell:(UITableViewCell *)aCell withConfigurationBlock:(IDPCellConfigurationBlock)configureCellBlock
{
if (configureCellBlock){
configureCellBlock(aCell);
}
}
It is pretty common to want to build a simple table to use as a menu or form, but using the built in API with the datasource and delegate callbacks don't make it easy to write or maintain. You may need to dynamically add/remove/update some cells, so using Storyboards by itself won't work.
I put together MEDeclarativeTable to programmatically build small tables. It provides the datasource and delegate for UITableView. We end up with an API where we provide instances of sections and rows instead of implementing datasource and delegate methods.
Related
Help me to get rid of with this dilemma that occurred yet when I tried to dequeued the cell (Custom Cell).Below are some steps and Indents that I did with my Project.
The very first is I drag and drop a UITableView in my ViewController and add the ViewController.h doing after this
#interface ViewController : UIViewController <UITableViewDataSource,UITableViewDelegate>
Then I made a Custom Cell with 3 UILabels and change the height of the Cell to 65.
After that I made a property in ViewController.m
#property (nonatomic,strong) NSMutableArray *myTodoTitles;
Then in method(ViewDidLoad) I did.
myTodoTitles = [NSMutableArray arrayWithCapacity:10];
[myTodoTitles addObject:#"Go for ride"];
[myTodoTitles addObject:#"Do University Assignments"];
[myTodoTitles addObject:#"Watch Show"];
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:[self.myTodoTitles count]-1 inSection:1];
[self tableView:self.myTodoTable cellForRowAtIndexPath:indexPath];
After that I just did these things in my ViewController.m
#pragma mark - Table view data source
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
NSString *myIdentifier = #"TodoCell";
TodoCell *todoCell = (TodoCell*)[tableView dequeueReusableCellWithIdentifier:myIdentifier];
todoCell.todoTitleLabel.text = [self.myTodoTitles objectAtIndex:indexPath.row];
return todoCell;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
return [myTodoTitles count];
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{
return 1;
}
But when I run the project it dequeued nothing.
Please help
Most likely that you have not connected your viewController to be the dataSource of your tableView. This could be done from Interface Builder or from the code. You can easily check it by adding self.myTodoTable.dataSource = self; at the very first of viewDidLoad method.
And also: what did you mean by `
[self tableView:self.myTodoTable cellForRowAtIndexPath:indexPath];`
in viewDidLoad ? Seems like you wanted to do
[self.myTodoTable reloadData];
There are to UITableView methods with similar name:
- (id)dequeueReusableCellWithIdentifier:(NSString *)identifier
and
- (id)dequeueReusableCellWithIdentifier:(NSString *)identifier
forIndexPath:(NSIndexPath *)indexPath
The first one will try to dequeue a reusable cell. If it returns nil you are responsible to create appropriate cell.
The latter one will always return a valid cell: you will have to register a certain class or NIB with that tableview beforehand though. Docs.
EDIT:
As ReDetection pointed out: first method will also return a valid cell as long as you had registered a proper class (or nib) with that tableview.
In your case that means that you should register TodoCell in viewDidLoad with your tableView.
If TodoCell is made without .xib:
[self.tableView registerClass:[ToDoCell class]
forCellReuseIdentifier:#"TodoCell"];
Or if it is made with .xib.
[self.tableView registerNib:[UINib nibWithNibName:#"TodoCell"
bundle:nil]
forCellReuseIdentifier:#"TodoCell"];
EDIT2:
Your code also seems to be missing the dataSource setting. Something like:
self.tableView.dataSource = self;
This will trigger initial reload.
You'd probably want to set a delegate (since your controller claims to adopt that protocol) in the same manner.
I am fairly new to this Native App dev - I have built an app which contains a UITableViewController to display messages - all works fine - but for styling reasons I need to change it from a TableViewController to a tableview embedded within a viewcontroller.
I have made a view controller containing a table view and relevant linked custom cells / fields and altered the associated header file to -
#interface NotificationsListTVController : UIViewController
but my table methods no longer fire and I'm not sure how to instantiate them?
(code below)
#pragma mark - Table view data source
- (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.GPTNotifications.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
static NSString *CellIdentifierRead = #"CellRead";
UITableViewCell *cell;
notifications *n = [self.GPTNotifications objectAtIndex:indexPath.row];
if (n.read == false) {
cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
CustomCellRead *cellReadB = (CustomCellRead *)cell;
cellReadB.notifTitle.text = n.notifTitleD;
cellReadB.notifDate.text = n.notifDateD;
cellReadB.notifMsg.text = n.notifMessage;
return cellReadB;
}
else {
cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifierRead forIndexPath:indexPath];
CustomCell *cellReadB = (CustomCell *)cell;
cellReadB.notifTitle.text = n.notifTitleD;
cellReadB.notifDate.text = n.notifDateD;
cellReadB.notifMsg.text = n.notifMessage;
return cellReadB;
}
}
Are you setting the delegate and datasource of your tableview to your class?
Something like:
self.myTableView.delegate = self;
self.myTableView.dataSource = self;
When you create a UITableViewController this is done for you, but if you add the table yourself you need to set them.
Also:
#interface NotificationsListTVController : UIViewController <UITableViewDelegate, UITableViewDataSource>
I do it this way in Interface Builder:
Make your TableViewController
Make your ViewController and add a ContainerView to it
Delete the segued embedded ViewController that comes with it
Select the ContainerView and draw a connection from viewDidLoad to your TableViewController
you'll get only once option: embed
Done. Your TableViewController will now get displayed within your ViewController.
Pass whatever Data you need forward from the ViewController to the TableViewController with the embedded Segue.
Make the following changes in NotificationsListTVController.h:
#interface NotificationsListTVController : UIViewController<UITableViewDataSource,UITableViewDelegate>
Also in NotificationsListTVController.m, dont forget to provide these two statements as well.
tableView.delegate=self ;
tableView.dataSource=self;
These are required to set the delegate methods.These two statements need to be provided after initializing your tableView. Like for instance :
tblView = [[UITableView alloc] initWithFrame:CGRectMake(100,200,320,420) style: UITableViewStyleGrouped];
tblView.delegate = self;
tblView.dataSource = self;
[self.view addSubview:tblView];
These methods you are referring to are the delegate methods which cannot be fired directly unlike other ordinary methods.
Hope it Helps!!!
So I'm trying to add a UITableView on the lower half of my ipad app which will be used to display a search result. This is how I did it.
I added a UIView
I added a UItableView onto the UIView
I then dragged the UITableView to the ViewController so it can connect to it for delegate and datasource.
This is what it currently looks like:
(It's at that middle top row)
So I added the following onto the viewcontroller class to generate the data
# pragma mark TableView properties
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 2;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"SearchResultCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if(cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
cell.textLabel.text = #"test";
}
The debugger would go through all these but would get stuck after the "cellForRowAtIndexPath" method:
It would just go through that and would not end until I stop the whole debugging. Not really sure what's going on.
Thoughts? Maybe you guys can point me to the right direction as to how I should generate my search results.
Thanks!
I usually find it much more faster and easier to use the free Sensible TableView framework to do automatic table view searches, instead of using the regular datasource/delegate system which I could never get right.
So I've been given an assignment in my Mobile apps class: make a color game app for the iphone.(The description of how to game works is at the top of the pasted viewcontroller.h file below.)
I'm very new to Objective-C and cocoa, but have managed to troubleshoot and fix a lot of things in this app. The problem I have right now is that I don't know how to properly initialize and send UITableViewCells to the view. I'm confused because all of the tutorials I've found online use datasource methods to change different attributes of the UITableView and the cells as well. I'm not sure how these methods will interact with the controls I've already placed. I'm confused because I added them by the storyboard file, not by defining tableview attributes with datasource code.
My immediate issue is that my program won't display the proper text to the cells textlabel and detailtextlabel.
I've looked everywhere online for UITableView and UITableViewCell tutorials, but they are all from years ago and I'm not sure if the advent of the storyboard has changed the way I would treat these controls.
All of the code I've written is either in the viewcontroller.m or viewcontroller.h files.
The method within ViewController.m file, that should call the cell and display text and detail text:
-(IBAction)enterClicked
{
//On enter- send instance colors to the colorTable row[i], perform comparisons and append the resulting symbols to the instanceResults String. Send instanceResults string to the resultTable row[i]. When game counter reaches 6, gameOver. If on comparisons check, the instanceColors are the same as the gameColors, then the player wins.
[self checkForLoss];
if(!self.gameOver)
{
resultOfGuess = [self comparePlayerInputToGameColors:guessColors];
[listOfGuesses addObject:guessColors];
[listOfOutcomes addObject:resultOfGuess];
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:_numberOfTurnsPlayed inSection:0];
UITableViewCell *thisCell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier];
thisCell.textLabel.text = [self.listOfGuesses lastObject];
thisCell.detailTextLabel.text = [self.listOfOutcomes lastObject];
[guessColors setString:#""];
if([self checkForWin:resultOfGuess])
[UpdateLabel setText:#"You have won!"];
else
[UpdateLabel setText:#""];
self.colorCounter = 0;
self.isStepOne = YES;
_numberOfTurnsPlayed++;
}
else
{
if([self checkForLoss])
[UpdateLabel setText:#"You have lost!"];
}
}
The UITableView DataSource Methods I've called at the bottom of the viewcontroller.m file:
#pragma mark - UITableViewDataSource protocol
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
if(section == 0)
return #"Guesses: Results:";
return 0;
}
-(NSInteger) numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
-(NSInteger) tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 6;
}
-(UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if(cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier];
}
return cell;
}
So my questions are: Can I change a control's properties with datasource methods, if I created the controls through the storyboard? How do I properly display the text in a uitableview's cells?
Edit/update: Thank you, I've used your advice jrturton, but now I've found something peculiar that may be the source of my problems. in my viewController.h file I've changed my header from
ViewController: UIViewController to ViewController: UITableViewController
Thinking that the datasource methods I call within the viewcontroller files have to be able to call the same methods and properties of the class that I call in the header-- Also, I see this done in other UITableView tutorial files.
The problem is that when I change the header to read-- ViewController: UITableViewController -- and I try to compile, I get this error:
Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '-[UITableViewController loadView] loaded the "2-view-3" nib but didn't get a UITableView.'
It compiles fine if I use just :UIViewController in the header file though.
Any ideas?
Further update: I''ve noticed within my storyboard that the only available ViewController object is a UIViewController object, while in the other tutorial files I've seen, this ViewController object is a UITableViewController object. I imagine this is my problem, but I can't seem to switch my UIViewController object to a UITableViewController. All I can do is create a new one, which isn't what I want, I imagine.
Your action method should update the data model (which I think it does, since it changes your listOfGuesses array). You then need to let your table view know that you have added or updated rows so that it can re-load them for you - check the UITableView documentation for reloading data or specific rows.
Creating a cell outside of the datasource methods isn't going to let that cell appear in your table.
At the moment I'm guessing you have 6 empty cells in your table view? You need to populate the text and detail labels in your cellForRowAtIndexPath method. The difference now there are storyboards is that you don't need to do the if (cell == nil) bit, as long as you have set the re-use identifier in your storyboard prototype cell then it will do all that for you. So your cellForRowAtIndexPath method can be reduced to:
-(UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath*)indexPath
{
// This will dequeue or create a new cell based on the prototype in your storyboard
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"Cell"];
// Put your actual configuration here based on your model array
cell.textLabel.text = #"Hello";
return cell;
}
Further hints (this is homework so I'm not giving full samples)
'indexPath.row` in the above method will give you the index from your model array that the cell refers to
You have defined the table as having 6 rows, but you are adding items to your model arrays as you go - so when the table asks for row 5, and your model only has 3 entries, you need to deal with this. Consider changing the number of rows in the table dynamically and using table view methods to indicate that new rows have been added. Again, see the UITableView documentation for this.
Typically the text is set in each cell by accessing the setText property:
[[cell textLabel] setText:#"static string"];
or
[[cell textLabel] setText:someNSString];
or with .dot notation
cell.textLabel.text = someNSString;
return cell;
BTW this is done in the method:
-(UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:
I am using a UISearchDisplayController to be able to display a table with custom cells based on some data I am retrieving from a server.
First I set the UISearchDisplayController inside my UIViewController.
self.searchController = [[UISearchDisplayController alloc]
initWithSearchBar:self.mySearchBar contentsController:self];
self.searchController.delegate = self;
self.searchController.searchResultsDataSource = self;
self.searchController.searchResultsDelegate = self;
My UIViewController also implements the UISearchBarDelegate, so I can determine when a search starts. I set up a block so when my api call returns it gets called and a dictionary of results is saved in the self.searchResults property:
- (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar
{
// here we make the api call
[api getSomeInfo:searchBar.text complete:^(NSDictionary *json) {
self.searchResults = json;
[self.searchController.searchResultsTableView reloadData];
}];
}
Now, the problem I have is that in my UITableViewDataSource method, where I return the custom cell. My cell is instantiated, but it's IBOutlets never get initialized, so I cannot set their content (text, images, etc) properly:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
if (tableView == self.searchController.searchResultsTableView) {
cell = [tableView dequeueReusableCellWithIdentifier:#"SearchResultsCellIndentifier"];
if (cell == nil) {
cell = [[SearchResultsCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
}
cell.customLabel.text = [self.searchResults objectForKey:#"customText"]; // cell exists but cell.customLabel is nil!!
}
}
Why is the content nil? Is there somewhere in my Custom Cell class where I should be setting the content up?
Thanks!
I think your problem is that you used the variable cellIdentifier when creating the cell, but a string constant when dequeuing.
Simply always recreating a cell will work, but is not efficient at all and leads to major memory leaks.
You should first set the cellIdentifier according to which table view you are in, and which kind of cell you need, then dequeue with that cellIdentifier, and then create a new one if needed.