I have created 5 static cells in UITableViewController scene. Everything working fine but I am not able to set the particular cell selected! If it is prototype cell then its simple but how could I set static cell selected? Following code raises BAD memory access exception! I have done this based on discussion on apple thread but not sure what's wrong! Could someone help please.
- (void)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
[super tableView:tableView cellForRowAtIndexPath:indexPath];
if(indexPath.section == _rating)
[tableView cellForRowAtIndexPath:indexPath].accessoryType =UITableViewCellAccessoryCheckmark;
}
Fixed this. I have to return UITableViewCell return type and have to used this method like below. It was recursive calling the methods and hence was failing.
- (UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [super tableView:tableView cellForRowAtIndexPath:indexPath];
if(indexPath.section == _rating)
cell.accessoryType = UITableViewCellAccessoryCheckmark;
return cell;
}
Related
I have a problem in my storyboard.It is working fine but when i try to change the content property of UITableView it caused following error
Assertion failure in -[UITableView dequeueReusableCellWithIdentifier:forIndexPath:], /SourceCache/UIKit/UIKit-2903.23/UITableView.m
Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'unable to dequeue a cell with identifier Cell - must register a nib or a class for the identifier or connect a prototype cell in a storyboard'
I want to design a grouped tableview with static cell.Thanks in advance
Code
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return 2;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 3;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
return cell;
}
if you use static cell, just comment all the UITableViewDatasourceDelegate method. so comment the following code:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return 2;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 3;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
return cell;
}
Wish this will help you!
Instead of using:
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
//-> This is used when using prototype cells (e.g) Dynamic TableView
Use:
UITableViewCell *cell = [super tableView:tableView
cellForRowAtIndexPath:indexPath];
//-> Since you chose Static TableCells you don't need to reuse instead use the cells you created in nib
I have encountered same issue, and I think I found the way to work this out.
Create a Controller extends from UITableViewController to wrap its controller, it will have default UITableViewDelegate and UITableViewDataSource methods.
Remove UITableView delegate and datasource
Delete default UITableViewDelegate and UITableViewDataSource methods from your controller file, coz it's static cells, so if these exist, will not appear
Hope it helps.
When using storyboard the tableview cell must be registered in the storyboard.That means cell must be added to the table and its identifier must be set.This identifier should be used in the code in cellForRowAtIndexpath
EDIT
In case of static cells the each purticular cells needed to be created in the nib and filled content via code or nib
Read this
Loading Table View Cells from a Storyboard
Excellent starter
You are not allowed to use static cells in a normal UITableView.
Instead you need to use UITableViewController to go with the static cells.
this and this may or might help.
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [YourArr count];
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return 44;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *CellIdentifier = [NSString stringWithFormat:#"cell %d",indexPath.row];
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
cell = nil;
if (cell == nil)
{
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
return cell;
}
Add this code in cellForRowAtIndexPath
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:nil];
}
else
{
UIView *subview;
while ((subview= [[[cell contentView]subviews]lastObject])!=nil)
[subview removeFromSuperview];
}
I am relatively new to using table view in ios. I am trying to edit data using different view and update the values from original view. I set cell identifier and wrote following code.
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return self.items.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath: (NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"NameIdentifier";
Item *currentItem=[self.items objectAtIndex:indexPath.row];
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
// Configure the cell...
cell.textLabel.text=currentItem.itemName;
return cell;
}
But I get the following error:
NSInternalInconsistencyException',
reason: 'UITableView dataSource must return a cell from tableView:cellForRowAtIndexPath:'
You need to check and make sure dequeueReusableCellWithIdentifier was able to dequeue a cell. It's crashing because it doesn't return a cell every time. If you were unable to dequeue a reusable cell you need to create a new one. Your code should look like this:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath: (NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"NameIdentifier";
Item *currentItem=[self.items objectAtIndex:indexPath.row];
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
cell = [[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier];
// Configure the cell...
cell.textLabel.text=currentItem.itemName;
return cell;
}
I am working with grouped tableview with multiple sections.
and I have to implement the functionality of multiple selection on didselectrow at indexpath
method. my code is as follows.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)path
{
UITableViewCell *cell = [tableView cellForRowAtIndexPath:path];
if (cell.accessoryType == UITableViewCellAccessoryCheckmark)
{
cell.accessoryType = UITableViewCellAccessoryNone;
}
else
{
cell.accessoryType = UITableViewCellAccessoryCheckmark;
}
}
which allows me to select multiple cells
but when I scroll my tableview at that time my selection disappears.
Your selection goes off when you scroll because it calls cellForRowAtIndexPath and there you have not handle selection.
To avoid this problem you can do as follows:
In didSelectRowAtIndexPath you can save index path of selected row as follows:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)path
{
UITableViewCell *cell = [tableView cellForRowAtIndexPath:path];
if (cell.accessoryType == UITableViewCellAccessoryCheckmark)
{
cell.accessoryType = UITableViewCellAccessoryNone;
//remove index path
[selectedIndexPathArray removeObject:path];
}
else
{
cell.accessoryType = UITableViewCellAccessoryCheckmark;
[selectedIndexPathArray addObject:path];
}
}
and in cellForRowAtIndexPath you can check whether cell is selected or not.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
//If selectedIndexPathArray contains current index path then display checkmark.
if([selectedIndexPathArray containsObject:indexPath])
cell.accessoryType = UITableViewCellAccessoryCheckmark;
}
Try this
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:nil];
if (self.tableView.isEditing) {
cell.selectionStyle = UITableViewCellSelectionStyleBlue;
} else {
cell.selectionStyle = UITableViewCellSelectionStyleNone;
}
return cell;
}
-(UITableViewCellEditingStyle) tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath {
return UITableViewCellEditingStyleMultiSelect;
}
-(IBAction) switchEditing {
[self.tableView setEditing:![self.tableView isEditing]];
[self.tableView reloadData]; // force reload to reset selection style
}
Hope this helps solving your problem.(ref)
Your selection disapear cause the method CellForRowAtIndexPath will be called at scroll.
You need to set the accessory again.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
...
// here
...
}
You are getting this issue because you are not tracking your row selections.When the callback method cellForRowAtIndexPath gets called for the rows that had disappeared/(scrolled up/down) the cell object no longer remembers whether it was selected or not. (reason those selections are disappearing)
I would suggest you to use a collection like NSMutableArray/NSArray to track the selected rows.
You can use either of these approaches.
This would be a quick working fix:
Add/Remove the index path object in didSelectRowAtIndexPath based on the users selection
and then based on the contents of that array u can toggle the value of cell.accessoryType for the corresponding cell.
Ideally,you can use a data bean/model with some boolean member called selected and u can update its value based on the selection made.Then instead of simply adding those index path u can add those meaningful data bean objects onto your array and get the selections back from the selected property of the bean.This approach would help u in getting back the row selections even if the user kills and restarts the app provided u persist the bean objects in database/archive..(But it all depends on ur use case and requirements!)
Hope this helped!
Apologies if this is a simple question but googling hasn't been able to help me.
I am planning to display 3 arrays of data in a Table View that has each array in a different section in the Table View.
Can any one provide me with a link to a good tutorial or sample code that could help me with this?
Once again I apologize if this is a simple question and answer but I am a newbie to Xcode and working on my first serious project for it.
Thanks!
In your TableViewController implement:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 3;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [[self getDataArray:section]count];//implement getDataArray
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
NSObject *data = [[self getDataArray:indexPath.section]objectAt:indexPath.row];//implement getDataArray
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];
//add Code to populate cell with data
}
return cell;
}
Other methods to probably implement:
- (UIView *)tableView: (UITableView *)tableView viewForHeaderInSection: (NSInteger)section
- (CGFloat)tableView:(UITableView *)aTableView heightForHeaderInSection:(NSInteger)section
I need help in using checkbox cell. I currently added the object to tableview. It looks ok until i tried building and running the program where I cannot check the checkbox. I am currently using a tableview which displays items runtime with a checkbox for each item so i can have multiple selections.
I am new to xcode and I have been stuck for a week with this problem. i tried google but still no luck.
Any snippets, answers, or explanations is very much appreciated.
First we need to edit this method: - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath. Assuming you generated a Navigation-based application, this method should already be there, only commented out. I don't know the exact details of your implementation, but you somehow have to keep track of the checkbox state for each cell in the tableView. For example, if you had a BOOL array, the following code would work:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if (checkboxArray[indexPath.row])
checkboxArray[indexPath.row] = NO;
else
checkboxArray[indexPath.row] = YES;
[self.tableView reloadData];
}
Now that we know what cells need to have a checkmark next to them, the next step is to modify how the cell is displayed. - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath handles the drawing of each cell. Building off the previous example, this is how you would display the checkbox:
- (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 (checkboxArray[indexPath.row]) {
cell.accessoryType = UITableViewCellAccessoryCheckmark;
}
else
cell.accessoryType = UITableViewCellAccessoryNone;
// Configure the cell.
return cell;
}
If we don't call reloadData, the checkmark will not show up until it goes off-screen and reappears. You need to explicitly set the accessoryType each time because of the way cells are reused. If you set the style only when a cell is checked, other cells that may not necessarily be checked will have a checkmark when you go to scroll. Hopefully this gives you a general idea on how to use checkmarks.