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
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 am using ios5 storyboards with a UITableViewController with a UITableViewCell subclass. I do not want to design the visual elements of the cell in the storyboard designer for the view, because I want to use a reusable subclass of UITableViewCell (specifically TDBadgedCell).
I have set my cell identifier in the storyboard designer, and all of the rows load correctly in the UITableView as long as I'm not setting any of the properties unique to TDBadgedCell. If I set the badgeString property though which is unique to TDBadgedCell, I get an exception. I narrowed down that dequeueReusableCellWithIdentifier: is not returning a cell of type TDBadgedCell.
I'm only running into this with a UITableViewController. I have a UIViewController with an embedded UITableView set up in the same fashion and it's not an issue. Any ideas?
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath*)indexPath
{
static NSString *CellIdentifier = #"PhoneNumberCell";
TDBadgedCell *cell = (TDBadgedCell*)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[TDBadgedCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
if ([cell isKindOfClass:[TDBadgedCell class]])
{
NSLog(#"It is TDBadgedCell");
}
else
NSLog(#"It is NOT TDBadgedCell");
I had a similar issue in that I am subclassing UITableViewCell but not using storyboard. Here is my solution to using different cell classes dependent on if the user had purchase the unlock feature of the app. Hope it helps someone.
In a nutshell, I had the cell with several objects including a UITextView object. I wanted to lock down the copy and paste feature of the UITextView object in the lite version but then release the feature once the user had purchased in in-app product.
I had two UITableViewCell classes, one with UITextView as it is and another with UITextView subclassed with canBecomeFirstresponder returning NO. That way the user could still scroll up and down the UITextview data but not copy and paste the data.
Here is the code and all I had to do was rename the reuse identifiers.
WHY? Because [self.tableview reloadData] would not rebuild the cells with the new class as the cell was still in existence. New cells off the screen would get the new class but existing ones would not. This solution rebuilds all cells once off after the purchase unlocking the added feature.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
if (your test if in-app was purchased is yes)
{
static NSString *MyIdentifier = #"MyCell";
FrontCell *cell = (FrontCell *)[tableView dequeueReusableCellWithIdentifier:MyIdentifier];
if (cell == nil)
{
cell = [[FrontCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:MyIdentifier];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
cell.shouldIndentWhileEditing = NO;
}
//....///
cell.trackDetails.text = [yourObject objectAtIndex:indexPath.row];
cell.trackDetails.delegate = self;
cell.trackDetails.tag = indexPath.row;
return cell;
}
else // inapp not purchased
{
static NSString *MyLockedIdentifier = #"MyLockedCell";
FrontCellLocked *cell = (FrontCellLocked *)[tableView dequeueReusableCellWithIdentifier:MyLockedIdentifier];
if (cell == nil)
{
cell = [[FrontCellLocked alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:MyLockedIdentifier];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
cell.shouldIndentWhileEditing = NO;
}
//....///
cell.trackDetails.text = [yourObject objectAtIndex:indexPath.row];
cell.trackDetails.delegate = self;
cell.trackDetails.tag = indexPath.row;
return cell; }
}
In storyboard,you can set the Custom Class property for a subclass of UITablviewCell.
Then dequeueReusableCellWithIdentifier method will return cell with the type of your subclass.
I think you are using wrong method for dequeuing the cells.
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
UITableViewCell *cell = [self.tblProfileInfo dequeueReusableCellWithIdentifier:#"PostCell" forIndexPath:indexPath];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
return cell;
}
You forgot for indexPath at the end.
I have a tableview that has groups. I would like to add a dummy cell at the top of each group, but not add it to the data. I dont want it saved. So if the top cell is clicked, its data passed will be blank and I can handle the passed view differently. I currently am configuring the cells manually.
So if group one had two entries, the display of those two entries would be prepended with a fake entry at what would be index 0
Below is a preview of what I am trying to do.
PS: Can one cell have a different disclosure icon? Does that break Interface Guidelines?
It would be something like this, you are not really adding anything to your model, you are just modifying your view:
- (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];
}
if ([indexPath row] == 0) {
//And any other default behavior
[[cell textLabel] setText:#""];
}
else{
//Your code for each cell
}
return cell;
}
The HIG doesn't mention anything about having different disclosure icons:
iOS includes some table-view elements that can extend the functionality of table views. Unless noted otherwise, these elements are suitable for use with table views only.
I have a tableview with 5 sections and variable number of rows in each section with a custom cell (for check and uncheck images on a cell). When I select a row in first section, tableview also selects any one of the row in the last section.
And when I scroll up and down, the checked rows are getting shifted randomly with in the sections.
The issue is that it's not there when I remove one section in the tableview. I.e even number of sections.
Can anyone help me?
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *kCustomCellID = #"MyCellID";
CustomCell *cell = (CustomCell *)[tableView dequeueReusableCellWithIdentifier:kCustomCellID];
if (cell == nil)
{
cell = (CustomCell *) [[[CustomCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:kCustomCellID]autorelease];
}
That is the code that I used.
I'm sure somewhere I did a mistake. But, I'm not able to find it.
this is because of reusing of cells in the table, read more about table reusing methodology.
To go in detail the changes made to a cell will be copied to others since the cells are reused to viewable cells.
We will need to see some code to properly diagnose the problem, specifically the implementation of - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {.
Are you correctly reusing the cells as specified in apples docs i.e.
static NSString *cellIdentifier = #"MyAwsomeCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier] autorelease];
}
UITableView not scrolling smoothly...(iPhone SDK) ..!!
I have implemented UITableView DataSource and Delegate methods in an individual separate classes.(one for delegate and one for datasource) in main program i write only:
//assume that all objects are allocated
ObjTableView.dataSource=ObjDataSource;
ObjTableView.delegate = ObjDelegate;
[self.view addSubView: ObjTableView];
when i run this code , UITable view appears but when i try to scroll it, it doesn't scroll smoothly.
I have also checked that UITableViewCell doesn't redraw once the cell is initialized.
can any one tell me why this happens ? How can i solve this problem ??
From comments:
ListDataSource *ObjListDataSource = [[ListDataSource alloc]initWithArray:[[sender object] valueForKey:#"List"]];
ListDelegate *ObjListDelegate = [[ListDelegate alloc]initWithArray:[[sender object] valueForKey:#"List"]];
tblList = [[UITableView alloc]initWithFrame:CGRectMake(0, 0, 320, 460)];
tblList.dataSource = ObjListDataSource; tblList.delegate = ObjListDelegate;
[self.view addSubview:tblList]; [tblShopList release];
More from comments:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSString *CellIdentifier = [NSString stringWithFormat:#"%i",indexPath.row];
UITableViewCell *cell = (UITableViewCell*)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithFrame:CGRectMake(0,0,320,100) reuseIdentifier:CellIdentifier] autorelease];
//custom cell code
}
return cell;
}
More Information:
I have used NSNotification which notifies to current class when parsing is complete, after receiving notification , current class method calls DataSource, Delegate methods (which is defined in a separate class file).
So UItableViewCell customization (which is in ListDataSource) and table view(in current class) both are in different classes.
A problem is
NSString *CellIdentifier = [NSString stringWithFormat:#"%i",indexPath.row];
The id needs to be the same for all cells of the same class, otherwise you never reuse them. As you can see in most examples, it is indeed a constant in most (all?) cases.
Little explaination on the reuseIdentifier: every time a cell gets out of screen, you can reuse it instead of creating a new one. To reuse it, you need a cell in queue with the same identifier as the one you pass to dequeueReusableCellWithIdentifier. The way you did, the cells are never reused, because each id is unique (they may or may not be reused in case a row reappears on screen, depending on queue size, which is not configurable AFAIK). This is why personalization of the cell should happen OUTSIDE the "cell == nil" block. Long story short, you are using the reuseIdentifier not as intendend.
I think Michele is correct, but I would also add that it looks like you are doing your cell customization where the cell gets created. What you should be doing is something more like this:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSString *CellIdentifier = #"CellIdentifier";
UITableViewCell *cell = (UITableViewCell)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithFrame:CGRectMake(0,0,320,100) reuseIdentifier:CellIdentifier] autorelease];
//custom REUSABLE cell code here, e.g. text color, etc.
}
NSString *cellText = [dataArray objectAtIndex:indexPath.row]; //assuming you have a simple array for your data
cell.textLabel.text = cellText;
return cell;
}
I would also add that I'm not sure why you are able to run the app with the code you have here, since UITableViewCell cell = ... is an invalid initializer. It should be UITableViewCell *cell = ....
It would be helpful to see how you are customizing your cell, since without that it's hard to see what's happening.