The function below starts the creation of cells from zero to n, with content retrieved from the model. I have a few cells in my table at the beginning which has static contents and I want function below ignore them and start from nth place to insert new data. How will I do that? In other words, how can I return an already-existing cell at nth place?
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
The method tableView:cellForRowAtIndexPath is needed for scrolling, as the tableView doesn't load all cells at once.
If you want to reload only a portion of your tableView you can use the method reloadRowsAtIndexPaths:withRowAnimation: or reloadSections:withRowAnimation:. This will reload only the specified cells.
If you have a performance problems, and don't want to load the static cells every time the tableView scrolls to them, you can store them in a property after they are created, and only return them. It would look somewhat like this:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
switch (indexPath.row) {
case 0:
//Static cell
if (self.staticCell == nil) {
self.staticCell = [UITableViewCell new]; //Instantiate properly here
//Customize cell
}
return self.staticCell;
break;
case 1:
// Other cells normally
break;
}
}
In pseudo-code:
if (indexPath.row == 0)
return some static cell;
else if (indexPath.row == 1)
return some other static cell;
else
configure cell N with data[N-2];
Related
I have a tableViewController, and under that i want one static cell and rest of all will be dynamic cells . I have already run for dynamic cells , but within same tableViewController i also need to add one static cell, how can i achieve it?
Please Help
Thanks in advance.
you could do something like the following:
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return self.dynamicContent.count + 1; // +1 for the static cell at the beginning
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.row == 0) {
// static cell
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"StaticCellIdentifier" forIndexPath:indexPath];
// customization
return cell;
}
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"DynamicCellIdentifier" forIndexPath:indexPath];
id contentObject = self.dynamicContent[indexPath.row];
// customization
return cell;
}
You cannot create static and dynamic cell at same time in a UITableViewController.
But you can hard code your static cell's data and load the data each time you reload your tableview.
You can keep all your cells in one section and keep checking for index path.row == 0 or create separate sections for them.
typedef NS_ENUM(NSUInteger, TableViewSectionType) {
TableViewSectionType_Static,
TableViewSectionType_Dynamic
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 2; // One for static cell, and another for dynamic cells
}
- (NSInteger)tableView:(UITableView *)tableView
numberOfRowsInSection:(NSInteger)section
{
switch(section) {
case TableViewSectionType_Static:
return 1; // Always return '1' to show the static cell at all times.
case TableViewSectionType_Dynamic:
return [myDynamicData count];
}
}
With this approach your cells will be split into two sections and it will be easier to manage. And it will always show one cell, as number of rows returned for TableViewSectionType_Static is 1 always. It will show the dynamic cells based on your data count.
I use UITableView with prototype cells and would like the top most cell to be an "adder" cell: when user taps on that cell, the segue is being performed. As the UITableView is being dynamically generated (except the top one) and cells are being reused, I have two question:
1 - is it possible to make one static cell while all the others will remain prototype cells?
2 - If not, how to implement this solution? I think, it has to be implemented in
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
but I have no idea, is this method right place to do it. Am I correct, to implement this custom cell, I need to check, whether indexPath.row = 0 and substitute the needed cell with custom, while programmatically shifting all the cells one row down?
Yiu can do on the Tap of Your cell, you can create two different cell, one your prototype cell and one for your details
in your
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.row == 0) {
AdderCell *cell = (AdderCell*)[tableView dequeueReusableCellWithIdentifier:#"AdderCell" forIndexPath:indexPath];
} else {
CustomCell *cell = (CustomCell*)[tableView dequeueReusableCellWithIdentifier:#"CustomCell" forIndexPath:indexPath];
}
}
on tap of your Adder cell in
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.row == 0) {
// add data to your row array and reload the tableRow
} else {
// do your tap action
}
}
I have a UITableViewController created in storyboard. It has two sections. The first section's rows contain controls laid-out in storyboard. I want to update the rows in the second section using values in an array.
I'm fairly new to iOS development. I understand how to use a UITableViewDataSource to update a table based on the array, but not how to restrict the updates to a specific section. Can anyone outline how to do this?
EDIT This seemed like a simple problem, so I thought I code would just obscure the question. Maybe I was wrong. Heres what I have:
My numberOfRowsInSection function returns 1 in the section number is 0, because the first section (the one I designed in storyboard) has a single row, otherwise it returns the number of elements in the backing data array:
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
if (section == 0)
return 1;
else
return [myData length];
}
My cellForRowAtIndexPath function creates a cell if the section number is 1. But I don't know what to do if the section number is zero. How do I avoid having to recreate the rows I laid-out in storyboard?
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
if(indexPath.section == 1)
{
cell.textLabel.text = [myData objectAtindex:indexPath.row];
}
else
{
// What to do here?
}
}
Well If you only have few static controls in the first section why won't you put these controls in a table header view instead? Thus you'll only have one section to worry about :)
In your method - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPathadd this
Create 2 differents UITableViewCells and reference them like this
if (indexPath.section == 1) {
NSString *CellIdentifier = #"DynamicCell";
VideoCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
//You are drawing your second section so you can use your array as values
cell.property1...
cell.property2...
cell.property3...
return cell;
}else{//If you have only 2 sections then else represent your first section
//You are drawing your first section
NSString *CellIdentifier = #"StaticCell";
VideoCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
return cell;
}
You can change the row value in the delegate method
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
To identify the section, just use:
indexPath.section
You can use reloadRowsAtIndexPaths: with an array of all the indexPaths that are in the wanted section, built with a loop and a NSMutableArray.
- (void)reloadSections:(NSIndexSet *)sections
withRowAnimation:(UITableViewRowAnimation)animation;
The parameter "section" is An index set identifying the sections to reload.
So I'm trying to make two tableviews in one view and I'm having some trouble.
I've read some other response on how to do it but they don't exactly help me.
In my .h file I made two outlets for two views calling them myFirstViewText and mySecondViewTex
So in my m files for - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
I want to be able to print out seperate values in each different controller and I'm not too sure since you only return 1 cell?
So far i've Done this
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *CellIdentifier = #"Rx";
static NSString *CellIdentifier2 = #"allergies";
UITableViewCell *cell = [tableView dequeueReusableHeaderFooterViewWithIdentifier:CellIdentifier];
UITableViewCell *cell2 = [tableView dequeueReusableHeaderFooterViewWithIdentifier:CellIdentifier2];
if(!cell){
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
if (!cell2) {
cell2 = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier2];
}
if (tableView == self.myFirstTextView ) {
cell.textLabel.text = #"HI JAZZY";//[RxDict objectAtIndex:indexPath.row];
}
if (tableView == self.mySecondTextView) {
cell.textLabel.text = #"BYE JAZZY";//[RxDict objectAtIndex:indexPath.row];
}
tableView = self.mySecondTextView;
cell2.textLabel.text = #"I love Jazzy :D";
return cell2;
This prints "I love Jazzy" in my first TableView and nothing gets printed in the second one. Why does this happen and how can I fix it?
Thanks :D
This method gets called by all tableViews that have an instance of your class set as their dataSource.
This means you need to check which tableView was asking for cell number so-and-so.
So, your method should basically look like this:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
if (tableView == rxTableView) {
//prepare and return the appropriate cell for *this* tableView
}
else if (tableView == allergiesTableView) {
//prepare and return the appropriate cell for *this* tableView
}
return nil; //because you don't expect any other tableView to call this method
}
My suggestion would be to set a tag on both of your table views and then in your tableview dataSource methods check for which the tag the table view your are in. So for instance some where in your code you can do:
myFirstTableView.tag = 1;
mySecondTableView.tag = 2;
later when your are in
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
if (tableView.tag == 1)
cell.textLabel.text = #"HI JAZZY";//[RxDict objectAtIndex:indexPath.row];
if (tableView.tag == 2)
cell.textLabel.text = #"BYE JAZZY";
}
Also if you have 2 tableviews with different sizes you can achieve this like this:
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
if (tableView.tag == 1)
return 1;
else if (tableView.tag == 2)
return 2;
}
One approach I don't see implemented too often is actually to use a NSObject subclass to act as the delegate and datasource for each table, not the view controller. It removes the need for the "if (tableView == someTable) ..." code, and might make both your view controller and UITableView code maintainable and readable.
You'd create an NSObject subclass for each table. These subclasses would contain the desired implementation of your UITableView datasource and delegate methods. You'd then instantiate one of each in your view controller and hook each up to its appropriate table.
Problem 1:
tableView = self.mySecondTextView;
cell2.textLabel.text = #"I love Jazzy :D";
return cell2;
What you are doing here is always returning cell2, setting its text "I love jazzy :D" so it will always fill the first table view because you would not have set the tableView=mySecondTextView before entering into the method. The delegate is always targeting firstTableView.
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath;
Problem 2:
if (tableView == self.myFirstTextView ) {
cell.textLabel.text = #"HI JAZZY";
//[RxDict objectAtIndex:indexPath.row];
//for printing in first table view return cell here like
return cell;
}
if (tableView == self.mySecondTextView) {
cell.textLabel.text = #"BYE JAZZY";
//[RxDict objectAtIndex:indexPath.row];
//for printing in second tableview return cell two here
return cell2;
}
Make sure the table you want to target is set before entering into this function. You can set it in numberofsection method, the view didload method or somewhere else from where you want to show or target table view (like clicking on some button). But you can't set it here.
in method
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
usually you use an array to set
[cell.textLabel setTex:#"row"];
but if I want to jump a row?
at example at indexpath.row I don't want to have this cell in my tableview, is possible?
Try this: Incorporate the tableView datasource method for row height.
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.row == NUMBER_TO_AVOID) {
return 0.0f;
}
return 44.0f; //standard cell height
}
I have done this in several similar situations. What you'll do is create a second array "activeItems". Or something like that. Iterate through your main data array and build the active array with the valid items. Than have your data source reference this array instead. This gives you an array that is accurately indexed to your table.
You can put a condition in cellForRowAtIndexPath. Try this:
data = [array objectAtIndex:indexPath.row];
If (data != nil){
[cell.textLabel setText:data];
}
else{
// code that handles data if null
}