I'm brand new to Xcode and Objective-C, and fairly new to programming in general so please correct me if I have a severe misunderstanding.
Here's what I'd like to accomplish:
Create a Table View (empty upon startup)
Have user add and name cells via a Bar Button (pushes to a different view with a name Text Field and "Create" button I'm assuming)
Each created cell pushes to a new Table View with similar add/naming functionality
Then each of those cells push to a Text View
It seems to me that the best way to accomplish the first part is by populating a string array, then assigning those elements to the corresponding cells. That's where I get stuck.
How do I populate a Table View with an array?
Should I create a new secondary Table View for every cell, or just populate the same one differently depending on which parent cell is selected?
And same question as previous for the Text Views at the end of the chain...multiple Text Views or just different text passed each time?
If you got this far, I sincerely thank you and please let me know if I need to clarify anything.
I hope you know how to create a table view.
Now you should create a NSMutableArray to save your strings.
#property (retain) NSMutableArray *stringsArray = _stringsArray;
so your viewDidLoad will look like this.
- (void)viewDidLoad
{
[super viewDidLoad];
UITableView *myTableView = [[UITableView alloc] initWithFrame:self.view.bounds style:UITableViewStyleGrouped];
myTableView.dataSource = self;
myTableView.delegate = self;
[self.view addSubview:myTableView];
[myTableView release];
self.stringsArray = [NSMutableArray array];
}
Now the table view delegates
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
return [self.stringsArray count];
}
- (UITableViewCell *)tableView:(UITableView *)tmpTableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"MainCell";
UITableViewCell *cell = [tmpTableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (nil == cell) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
cell.textLabel.text = [self.stringsArray objectAtIndex:indexPath.row];
return cell;
}
Now when you click on your barbutton to add new user, you must add it to strings array and just call [tableview reloadData];
I didn't understand why you want a text view.
Hope this helps!
Read from here for complete reference of uitableview UITableView Tutorial : Introduction to iPhone TableView
Related
I'm working on an application that has multiple views, taking data from one view and storing it in a table in another. I have labels that are updated with data when a calculate button and a button that is hopefully going to store the data from those labels on their own cell in the UITable in another cell. I'm currently lost on how I would set up my UITable to create a new cell and pass the data to that cell every time the validate button is pressed.
This is basic MVC behavior. Table cells are loaded at display time in the UITableView datasource delegate methods. The data should be loaded from some type of store, in your case most likely an array.
When you want to update the data (from anywhere), simply update the data store (array).
Reload the UITableView at will with the reloadData method (or whenever the view appears).
So the idea is that you want to store your UILabels' text values in UITableViewCells on the press of a button?
If this is the case, I would store each text value as an element in an NSArray after every time your button is clicked, like so:
// Given:
// 1.) Your labels are IBOutlets
// 2.) Your labels follow the naming convention label1, label2, label3, etc
// 3.) You have an initialized class variable NSMutableArray *labels
// 4.) NUM_OF_LABELS_IN_VIEW is the number of UILabels in your view
// 5.) myTableView is an outlet to your UITableView, and its delegate and datasource are set to your view controller
-(IBAction)buttonPressed:(id)sender{
self.labels = [[NSMutableArray alloc] init];
for (int i=0; i < NUM_OF_LABELS_IN_VIEW; i++){
[labels addObject:[self valueForKey:[NSString stringWithFormat:#"label%i", i]].text ];
}
[self.myTableView reloadData];
}
And your data source methods should look something like this:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [self.labels count];
}
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *cellIdentifier = #"MyCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if(!cell) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:Cellidentifier];
}
cell.textLabel.text = self.labels[indexPath.row];
return cell;
}
If the UITableView is in a separate view controller, just assign the NSArray *labels to a #property on the presenting view controller.
Basically I'm making a list view that you can add things to the top of. The best way I can think of doing this is to store the UITableViewCells themselves in a NSMutableArray — Because I can simply pull them from the array them with all their data inside the object, and this list view will never be over 10 cells long.
Also note that I'm using Storyboards, hence the initWithCoder use.
The following code is what I'm trying, and it doesn't work:
// This is where my NSMutableArray is initialized:
- (id)initWithCoder:(NSCoder *)aDecoder
{
if (self = [super initWithCoder:aDecoder]) {
if (!_CellsArray) {
UITableViewCell *cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"TestCell"];
_CellsArray = [NSMutableArray arrayWithObject:cell];
}
}
return self;
}
//UITableView Delegate & DataSource Methods
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"TestCell"];
[_CellsArray insertObject:cell atIndex:0];
return [_CellsArray objectAtIndex:indexPath.row];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 10;
}
I realize I may be approaching this in the wrong way, that's why I'm here though :)
Thank you.
edit: fixed a type in the code (TimerCell -> UITableViewCell)
Let's look at the order things get called in and what happens.
Your view controller is unarchived, so your initWithCoder: method is called. This method creates a mutable array and puts one instance of TimerCell into it. Said instance is not further configured (unless you've overridden initWithStyle:reuseIdentifier: to do some configuration).
Your data source method tableView:numberOfRowsInSection: is called, and it tells the table view there are ten rows.
Thus, your tableView:cellForRowAtIndexPath: is called ten times. Each time, it creates a new instance of UITableViewCell and inserts it into your mutable array. (After ten calls, your mutable array contains one TimerCell at index 10 and ten UITableViewCells at indices 0-9.) It does nothing to configure the cell's contents or appearance, then it returns the cell at the specified row index. On the first call, you're asked for row 0, so the cell you just created and inserted at index 0 is returned. On the second call, you're asked for row 1, so the cell at index 1 in your array is returned -- since you just inserted a new cell at index 0, the cell you created on the last call has shifted to index 1, and you return it again. This continues with each call: you return the same unconfigured UITableViewCell ten times.
It looks like you're trying to out-think UIKit. This is almost never a good thing. (It's been said that premature optimization is the root of all evil.)
UITableView already has a mechanism for cell reuse; it's best to just keep track of your own cell content and let that mechanism do its thing. I took so long to type this that other answers have been written describing how to do that. Look to them, or to Apple's documentation or any third-party UITableView tutorial.
Why don't you just store the cell information in an array. Then in the -cellForRowAtIndexPath: method, just extract the data needed to change each cell.
Here is a simple example:
//Lets say you have an init like this that inits some cell information
- (id)initWithCoder:(NSCoder *)aDecoder
{
if (self = [super initWithCoder:aDecoder]) {
cellArray = [NSArray alloc] initWithObjects:#"firstCell",#"secondCell",#"thirdCell",nil];
}
return self;
}
//then for each cell, just extract the information using the indexPath and change the cell that way
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
// Configure the cell...
cell.textLabel.text = [cellArray objectAtIndex:indexPath.row];
return cell;
}
Table views don't store things. Rather, they just ask for the data they want to display, and you typically get that data from elsewhere (like an NSArray, or an NSFetchedResultsController). Just store the things you want into some data container, and let the table display them for you.
// Probably your data model is actually a member of your class, but for purposes of demonstration...
static NSArray* _myArray = [[NSArray alloc] initWithObjects:#"Bob", #"Sally", #"Joe", nil];
- (NSInteger) tableView:(UITableView*)tableView numberOfRowsInSection:(NSInteger)section
{
return [_myArray count];
}
- (UITableViewCell*) tableView:(UITableView*)tableView cellForRowAtIndexPath:(NSIndexPath*)indexPath
{
static NSString* CellIdentifier = #"TestCell";
// Make a cell.
UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if( cell == nil ) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
// Setup the cell with the right content.
NSString* aString = [_myArray objectAtIndex:[indexPath row]];
cell.textLabel = aString;
return cell;
}
Now if you want more stuff in the list, add it to your array, and you're done.
Edit: On another note, initWithCoder: isn't generally the best place to do initialization for a view controller. Reason being, at the point that it's called, there's a good chance that stuff isn't loaded yet (IBOutlets, for example). I tend to prefer viewDidLoad (don't forget to cleanup in viewDidUnload in that case), or awakeFromNib.
When I scroll down and up again my text in tableView will disappear.
And my code is:
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [screenDefBuild.elementsToTableView count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *MyIdentifier = #"MyIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MyIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:MyIdentifier];
}
ScreenListElements *currentScreenElement = [screenDefBuild.elementsToTableView objectAtIndex:indexPath.row];
cell.textLabel.text = currentScreenElement.objectName;
currentRow++;
return cell;
}
- (void)viewDidLoad
{
[super viewDidLoad];
tableView = [[UITableView alloc] initWithFrame:self.view.bounds];
[tableView setDataSource:self];
[self.view addSubview:tableView];
}
I also want to fill my table view to entire screen. (grey strap on the top).
I don't know what you're doing with this variable
currentRow++;
But whatever you use that for, i'd wager its breaking your code.
the UITableView will call cellForRowAtIndexPath every time a cell is about to appear on screen regardless of whether it has been on screen before or not. When you scroll down and then scroll back up this variable will have increased beyond the bounds of your data, hence you get empty cells.
You need to design this method in such a way that it can create any cell in the table view at any time. You can't rely on the order that the cells will be made and with scrolling you will have to make the same cell over and over again. Only use indexPath to figure out which cell you are currently supposed to be making.
http://developer.apple.com/library/ios/#documentation/UIKit/Reference/UITableView_Class/Reference/Reference.html
Answer for the second part of the question- grey strap. You are adding the table view to current view, so you should use the size property of self.view.frame but not the origin. You want this to be set to 0,0.
Change
tableView = [[UITableView alloc] initWithFrame:self.view.bounds];
to
CGRect viewFrame=self.view.frame;
viewFrame.origin=CGPointZero;
tableView = [[UITableView alloc] initWithFrame:viewFrame];
As for the first part of your question- it's strange, as you seem to do everything properly. One thing i may suggest is to add [tableView reloadData]; in the end of viewDidLoad.
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'.
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!
You could present the view modally like this
YourViewController2 *viewController2 = [[YourViewController2 alloc]initWithNibName:#"YourViewController2" bundle:nil];
[self presentModalViewController:viewController2 animated:YES];
Do you have more than one view to present? If so you will need to create an array with the names, pass it into the tableview and then present the correct view for the row selected based on the indexPath.row.
you'll have to open your MainWindow.xib and add a navigation controller to it. Then add a navigation controller outlet to your app delegate and connect them. Then you'll need to set the navigation controller's view as your main window's view.
You can add a table view to any iPhone app fairly easily, just by creating a new UITableViewController subclass from the File -> New command.
Even if you go this route, I would suggest creating a new navigation-based project to use as a template/cheat-sheet.
I have scoured the internet looking for a good tutorial or posting about having a UITableView populated with a UITextField in each cell for data entry.
I want to keep track of each UITextField and the text written within it while scrolling. The tableView will be sectioned. I have been using a custom UITableViewCell but I'm open to any method.
Also, is it possible to use the textFields as ivars?
If any of you could point me in the right direction, it would be greatly appreciated.
Thank you in advance!
To solve your problem you have to maintain an array, with some number (number of textFields you added to all cells) of objects.
While creating that array you need add empty NSString objects to that array. And each time while loading the cell you have to replace the respected object to respected textField.
Check the following code.
- (void)viewDidLoad{
textFieldValuesArray = [[NSMutableArray alloc]init];
for(int i=0; i<numberofRows*numberofSections; i++){
[textFieldValuesArray addObject:#""];
}
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
// Return the number of sections.
return numberofSections;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return numberofRows;
}
- (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:identifier];
CustomTextField *tf = [[CustomTextField alloc] initWithFrame:CGRectMake(5,5,290,34)];
tf.tag = 1;
[cell.contentView addSubView:tf];
[tf release];
}
CustomTextField *tf = (CustomTextField*)[cell viewWithTag:1];
tf.index = numberofSections*indexPath.section+indexPath.row;
tf.text = [textFieldValuesArray objectAtIndex:tf.index];
return cell;
}
- (void)textFieldDidEndEditing:(UITextField *)textField{
int index = textField.index;
[textFieldValuesArray replaceObjectAtIndex:index withObject:textField.text];
}
First of all, you must understand that UITableViewCell and UITextField are just views, they are not supposed to hold data, they are just supposed to display them and allow the user to interact with them: The data should remain stored in the controller of the table view.
You have to remember that UITableView allows you to reuse UITableViewCell instances for performance purpose: what's displayed on the screen are actually the only subviews UITableView keep there. It means that you'll reuse one cell that already has a text field in it and set the text on that field directly. When the user will tap on the field it will edit it and you'll have to get the value back from it when the user will have finished.
The fastest way, would be to use what Satya proposes, that is building normal UITableViewCell and insert into a UITextField (there's no need for a CustomTextField class...). The tag will allow you to get back to the text field easily... But you'll have to setup your text field so it behaves properly when the table view resizes or if a label in the same cell changes.
The cleanest way to do that is to subclass UITableViewCell and setup the layout of your label and text field, and you can provide the text field as a property of the custom subclass.
I have used Textfields in tableview for data entry.
I have customised the UITextField class in a separate class called Utility :
In Utility.h
#interface CustomUITextField:UITextField{
NSInteger rowNumber;
}
In Utility.m
#implementation CustomUITextField
#synthesize rowNumber;
#end
My tableView cellForRowAtIndexPath method is
- (UITableViewCell *)tableView:(UITableView *)theTableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *Identifier = #"Cell";
UITableViewCell *cell = [theTableView dequeueReusableCellWithIdentifier:Identifier];
if(cell == nil)
cell = [self reuseTableViewCellWithIdentifier:Identifier withIndexPath:indexPath];
CustomUITextField *itemNameTextField = (CustomUITextField *)[cell.contentView viewWithTag:TEXTFIELD_TAG];//this is the tag I have set in reuseTableViewCellWithIdentifier method for textfield
itemNameTextField.rowNumber = indexPath.row;
itemNameTextField.text = #"";//you can set it for the value you want
if(itemListTable.editing)
itemNameTextField.borderStyle = UITextBorderStyleRoundedRect;
else
itemNameTextField.borderStyle = UITextBorderStyleNone;
return cell;
}
You can customise the delegate methods of UITextField for CustomUITextField & can save the text entered in a particular row's textfield by accessing the CustomTextField's row number.
Just try with this.
I had the same problem here is some code i found that treats this problem . it puts the data enterd in a Array Look at the Debugger console to see the results of the text being typed here's the link TextFieldCell. . Happy Codeing