I am using UItableViewController and I add label to the cell programatically , the label reads data from json array , on scrolling the cell reuse and the label data change ,
there is any way to prevent this issue ?
Your question is not clear.!! but according to your problem you might not set proper value(array count) for
-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
and find the exact index in array using "indexPath.row"
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
if you provide your code what you've written may help us to re correct it
use following way :
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *CellId = [NSString stringWithFormat:#"CellId%d%d",indexPath.row,indexPath.section];
if (!cell)
{
cell = [[[CustomCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellId] autorelease];
}
return cell;
}
Dont use this like of code.It is used to reload the data.
cell = [[CustomCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellId];
Related
Sorry guys its me again.
In my project i used UITableview for showing weather.so, I need to show the first row text to UILabel without any button action or watever. I just want cell text to UILabel without any action.
ex:
In the tableview first cell showing text as "Lovely IOS"
I want to show the same text to UILABEL without any action. I took UILabel in the xib.
Thanks in advance
Any sample code please.
you only set action for particular cell
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.row == 1){
//set action for cell
}
}
In the method - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath equate
cell.textLabel.text = [array objectAtIndex:indexPath.row];
LabelName.text= cell.textLabel.text;
You have two options for this either you add add UILable or set the text to he cell.textLabel.text in the following method.
(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
You have the data for your cell so what's a big to UIlabel .You just need to set the same text there.
Updated:-
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
NSString *cellText = cell.textLabel.text;
you will get the text.
I tried the code below, but the output is always 0.000000:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"CellNotification";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
cell.textLabel.text = #"Test Test Test. I am a cell.";
NSLog(#"%f", cell.textLabel.frame.size.width);
return cell;
}
How can I know what the width of a default UITableViewCell is? I need this information because I have to set the height for UITableViewCell in
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
The width of the cell will be the width of the table, unless your table is grouped, in which case it is slightly smaller.
However, you probably want the width of whatever label you are using to display the text rather than the cell itself.
A further warning is that the heightForRow... method is called for every row in the table before any cells are created, so you may have to use a known value instead.
The NSLog you are using above is asking for the width of the textLabel within the cell, not the actual cell.
NSLog(#"%f",cell.frame.size.width);
Additionally, if you aren't using the grouped table style, the cells width should return the same as the width of the table.
EDIT: I'm not really sure if this was the question, but if you're asking how to set the width of your cells, you don't have to. This is handled for you.
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
NSLog(#"%#",NSStringFromCGRect(cell.textLabel.frame));
}
EDIT 2:
Try changing this:
if (cell == nil)
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
cell.textLabel.text = #"Test Test Test. I am a cell.";
To this:
if (cell == nil){
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
cell.textLabel.text = #"Test Test Test. I am a cell.";
I think you should test your textLabel width in:
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
i've a UITableView and I'm reading a data from a web service.
the data from the web service may change at any time, so i have to refresh my data periodically.
i've managed to refresh the data and store it in an NSArray, but the UITableView won't display those data.
i tried
[myTableView reloadData];
but it have no effect.
EDIT:
i've implemented all the methods to load the data from an NSArray to the UiTableView.
this works when the NSArray is initialized in the ViewDidLoad.
but if the NSArray changed while the application is running, the UITableView Will not display those changes.
You need to implement the UITableViewDataSource delegate protocol, specifically - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
Use this method to set up the cell. You can use the row property of indexPath to determine which cell you are setting up and provide it with data from your array.
For example
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
id item = [dataArray objectAtIndex:indexPath.row]; // Whatever data you're storing in your array
cell.textLabel.text = [item description]; // Substitute this for whatever you want to do with your cell.
}
EDIT:
reloadData should call
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView and
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
to see if there are any cells to be drawn. Make sure you implement these methods as well and return non-zero values or your table view won't try to draw any cells and - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath won't be called.
Parse
You may also be interested in this library which claims to make remote data-driven tables a lot simpler.
You have to call the function where you put the content into the table.
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.