I am using a custom UITableViewCell class. My cell has multiple buttons (4 to be precise) on it and the button clicks are handled in the UIViewController which uses this cell class.
I was trying to use the button's tag to calculate the row number on which the button was clicked. But doing this causes an issue if a cell was not created and instead uses a free object. In that case the tag and the row number do not match.
Can someone please tell me how I can handle this case? If I give the same tag to all buttons in different rows, how can I identify the row on which the button was clicked?
Thanks a lot.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
MyTableCell *cell = (MyTableCell *) [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
// whatever you have now
}
// Set up the cell...
cell.myListViewController = self;
int tag = indexPath.row;
cell.button1.tag = tag;
cell.button2.tag = tag;
cell.button3.tag = tag;
....
}
This code will have a unique tag for buttons in each row. You are setting the tag not in the new cell creation but for all cases, including reuse.
Related
In my tableview have custom cells that I initialize from a UITableViewCell class. I have sections for first letters of records and have an indexPath that is being created dynamically.
I wanted to add a search display controller to my tableview. So I did, created all methods to filter data. I am sure that my functions are working well because I am printing array count to screen for search results.
My problem is that the first time view loads, the data is on the screen. But when I hit the search input and type a letter, than I get 'UITableView dataSource must return a cell from tableView:cellForRowAtIndexPath:' error. After I used a breakpoint I saw that my custom cell is nil after searching. Data is exist, but cell is not being initialized.
Here is the code I use for custom cell initializing:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"ObjectCell";
SpeakerCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
NSDictionary *myObject = [[sections valueForKey:[[[sections allKeys] sortedArrayUsingSelector:#selector(localizedCaseInsensitiveCompare:)] objectAtIndex:indexPath.section]] objectAtIndex:indexPath.row];
cell.label1.text = [myObject objectForKey:#"myValue"];
return cell;
}
I believe I made a mistake when putting controls in IB. So I added screenshots of objects:
Connections inspector for my table view
Connections inspector for my search display controller
EDIT: Problem is actually solved, I have used a UISearchBar instead of Search Display Controller but I guess this issue remains unsolved. So I'm willing to try any ways to make it work.
As of here search display controller question,
you need to access the self.tableView instead of tableView:
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:#"CellId"];
// do your thing
return cell;
}
For those using iOS 5 and StoryBoards, you would want to use the following method instead of initWithIdentifier:
initWithStyle:(UITableViewCellStyle)stylereuseIdentifier:(NSString *)reuseIdentifier
Example:
NSString *cellIdentifier = #"ListItemCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
}
I'm not sure about how this should work in storeboarding.
But normally you would check if the [tableView dequeueReusableCellWithIdentifier:CellIdentifier] returns a cell.
Because if the cell in not loaded before or there aren't any cells to reuse you will have to create a new cell:
SpeakerCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[SpeakerCell alloc] initWithIdentifier: CellIdentifier];
}
Also when in declaring local variables in Objective-C we tent not to capitalize the first letter.
I had the same issue, with custom cells (built in Storyboard) not being drawn as soon as the first letter was put in the search field. The search was successful however.
Finally I found a good tutorial from Brenna Blackwell suggesting to configure manually the cell drawing in the corresponding subclass of UITableViewCell, adding UILabels and other items.
I've used Xcode 4.2 to create a storyboard-based iOS application.
One of my screens contains a UITableViewController, using dynamic custom cells.
So far - so good.
Now, I wanted to add a UISearchDisplayController to allow filtering my list.
For some reason, the UISearchDisplayController won't display my custom cells, and I can't find a way to force it...
This is what my cellForRowAtIndexPath method looks:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"QueueListCell";
QueueListTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[QueueListTableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle
reuseIdentifier:CellIdentifier];
}
assert(cell);
if ([tableView isEqual:self.searchDisplayController.searchResultsTableView]) {
indexPath = [_indexPathsForSearchResults objectAtIndex:indexPath.row];
}
// Set up the cell...
NSDictionary* itemDict = [_ListItems objectAtIndex:indexPath.row];
cell.labelQueueName.text = [itemDict objectForKey:kQueueName];
cell.labelQueueNumItems.text = [[itemDict objectForKey:kQueueNumItems] stringValue];
return cell;
}
Any thoughts on how to get this working? I mean, my UISearchDisplayController table DOES show the correct number of results (I know that since I can click on them, and I added an NSLog to let me know what I'm clicking on...)
This is my table view
This is how the search display table looks like...
My problem/question is how to make the UISearchDisplayController table view show my custom cells?
Any help appreciated...
Reuven
Answer specific to query
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier];
}
For Complete example, have the sample code from apple's site.
Step by step illustration
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
i have a tableview that contains a uiwebview in its first row. i would like to change this tables' webview object with new one when user clicks a button. i am using the code given below but it does not work fine. older object is there and the newer one is over it although i recreate the webview. how can i remove the older one from cell?
thanks...
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
NSLog(#"NİL.......");
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
} else {
NSLog(#"NOT NİL.......");
}
[cell addSubview:webView];
return cell;
}
Since you are using "dequeueReusableCellWithIdentifier", your should reconfigure the cell each time when the cell is displayed.
Please remember that the cells with same identity will be reused. It's better to set the same identity to one particular type of cells, typically cells with same subviews and layout.
This is sample for how to load data and reconfigure a cell: http://code.google.com/p/tweetero/source/browse/trunk/Classes/MessageListController.m
Here is a tutorial to get familiar with UITableView:
http://developer.apple.com/library/ios/#documentation/userexperience/conceptual/TableView_iPhone/CreateConfigureTableView/CreateConfigureTableView.html
I have a UITableView with several datasources. This is because, I need to switch the data with a UISegmentedControl, and if I add them as subviews, I cannot use the statusBar to scroll up, etc.
At first, I show a login screen:
self.tableView.dataSource = loginTableView;
self.tableView.delegate = loginTableView;
[self.tableView reloadData];
Then, once the user has logged in, I do the following to change to index:1 of the segmentedControler, which is their profile:
self.tableView.dataSource = profileTableView;
self.tableView.delegate = profileTableView;
[self.tableView reloadData];
However, the table view updates, but is a bit of a mix between the two dataSources. Some of the text has changed, some is overlapping, while some of it is completely missing.
Is there another way I should be changing the dataSource for a UITableView?
Thx
I had the exact same problem. My solution was to make the tableView hidden, change it's source, reload the data and make the tableView visible again.
Example in C# (MonoTouch):
tableView.Hidden = true;
tableView.Source = newTableViewSource;
tableView.ReloadData();
tableView.Hidden = false;
Not sure why this is happening from the code you have posted.
Instead of changing the delegate and datasource, swap out whatever ivar represents the data being displayed:
- (NSArray*)tableData{
if(showingLogin)
return self.loginData;
return self.profileData;
}
Now you only have 1 UITableViewController instance, but a BOOL to tell you which datasource to use.
The table view is caching the cells internally it uses for displaying your data. So if you change the data source you should also check that your is - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath method is updating all the cells to the correct new values.
From your description it sounds like it is using the cached UITableViewCell instances and is not updating it to the correct new data in all cases. Perhaps code like this:
- (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.frame = CGRectZero;
cell.textLabel.font = //Set font;
cell.selectionStyle = UITableViewCellSelectionStyleNone;
cell.textLabel.text = #"My Text for this cell"; // <==== Not good! Move it out of this if block
}
// Set cell text here
}
The simplest solution I found for this sort of problem is to just make the String you use for the cell creation (CellIdentifier) depending of the data Source. In this case you don't mix the cell of the different content types (and this helps you also if the cells need to have a different look depending on the mode).
I had this problem, turned out it was because my CellIdentifiers were the same...
static NSString *CellIdentifier = #"Cell";
Change one of them and the cells layout properly
static NSString *CellIdentifier2 = #"Cell2";
Wow, that's freaky.
The last time I did something like this, I simply used multiple views, hiding one and showing another when the segmented control was tapped. There are other possible solutions, but this is probably easiest and perhaps most efficient.
I have the same issue and what you have to do is use a different cell identifier within - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath.
if (self.segmentedControl.selectedSegmentIndex == 0) {
self.cellIdentifier = #"segmentOne";
} else {
caseAtIndexPath = [self.awaitingReviewCaseList caseAtIndex:indexPath.row];
self.cellIdentifier = #"segmentTwo";
}
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:self.cellIdentifier forIndexPath:indexPath];