I want to add an image using the cell.imageView setImage: method. However, depending on field from an array (in the form of an NSString and called using [dog types]) I need the image at the left-hand side of the cell to change to an image which reflects the type of dog.
How do I go about doing this? Thanks.
As you know for fill the cells contents you have to use the delegate method:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath;
so, you have to put your IF inside this method and use indexPath.row to understand witch row you are drawing.
Here a simple example:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"cell"] autorelease];
}
UIImage *a,*b; //Remeber to init with your images:)
if(indexPath.row == 1)
{
[cell.imageView setImage:a];
}
else
{
[cell.imageView setImage:b];
}
return cell;
}
I hope it's what you was looking for :)
I think you can deffinatly can do wht you want to do.
By chacking condition in cellForRowAtIndexPath method :
if(indexPath.row == 0) // for first cell of tableView
if(indexPath.row == 1) // for second cell of tableView
hope you can understand...
even if any problem leave a comment...and mark as correct if you got resolved...
Related
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!
I have seen other questions on here related to this, but I have their solutions in place, and things still move around when I scroll.
Basically, I have a table of data and I want the first and only the first row to have a UITableViewCellAccessoryDisclosureIndicator. The problem is, when I scroll around, the indicator duplicates, deletes, and moves to other cells. Here is my code..
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = (UITableViewCell *) [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if(cell == nil){
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
if(indexPath.row == 0) {
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
cell.textLabel.text = [tabledata objectAtIndex:indexPath.row];
return cell;
}
The problem is something with the indexPath.row variable.. its somehow returning 0 in other cells that aren't the very first (when it comes to displaying cells). HOWEVER... the data is always right from my array(which implies the value HAS to be correct) and in my
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
method, i only wish to change screens when row 0 is clicked.. and regardless of where I have scrolled to, no cells trigger except the very first. So it seems THAT check is always correct while the one inside cellForRowAtIndexPath is not...
Most likely, you are re-using cells that already have the accessoryType set. You need to explicitly set it to NOT show on cells where it shouldn't.
if(indexPath.row == 0){
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
} else {
cell.accessoryType = UITableViewCellAccessoryNone;
}
I made a UITableViewCell and I have 20 rows in that table in which 5 at a time on screen.
I have set accessory view checkd mark in didSelect delegate method on which row is being selected. My concern is let suppose first row is selected and its accessory type is checked, now if i scroll the table we see the sixth one is also checked. I know that the cell is reusing itself and not creating itself again.
The model should be able to handle which cell is checked and which is not. To simplify the problem, you can keep an array which will the NSIndexPaths that should be checked. If only one can be checked at the time, an ivar of the type NSIndexPath is more than enough.
- (void)tableView:(UITableView *)aTableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if ([[aTableView cellForRowAtIndexPath:indexPath] accessoryType] == UITableViewCellAccessoryCheckmark)
{
// Ok this one is selected, so we will remove it from the Reference Array.
}
else
{
// Ok this one doesn't has a checkMark
// First add the checkmark
[[aTableView cellForRowAtIndexPath:indexPath] setAccessoryType:UITableViewCellAccessoryCheckmark];
// Add the NSIndexPath to the Array of references
}
}
In the delegate method
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
NSString *cellId = [NSString stringWithFormat:#"cell%d",indexPath.row];
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellId ];
if (cell==nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1
reuseIdentifier:cellId ] autorelease];
}
}
Set different cell ID to different cell row.
I have been trying to figure out how to set the accessoryType to UITableViewCellAccessoryCheckmark when the cell is selected but am having trouble finding a decent example of this.
If you know how to do this or a good tutorial could you please let me know that would be great.
To restrict the user to just one selection, meaning to create an exclusive list of one choice only, you could follow these steps;
Firstly, have a global index path declared in your .h file to keep track of the already selected cell ->
NSIndexPath *oldIndexPath;
When you create the cells, be sure to set the accessory type to none, so that no cell is selected by default when the table is seen;
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"CellIdentifier"];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"CallIdentifier"];
cell.accessoryType = UITableViewCellAccessoryNone;
}
return cell;
}
Finally, in the didSelectRowAtIndexPath delegate method, add the following code which will remove the checkmark from the already selected cell, and add a checkmark to the newly selected one.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
if (oldIndexPath==nil) { // No selection made yet
oldIndexPath=indexPath;
[cell setAccessoryType:UITableViewCellAccessoryCheckmark];
}
else {
UITableViewCell *formerSelectedcell = [tableView cellForRowAtIndexPath:oldIndexPath]; // finding the already selected cell
[formerSelectedcell setAccessoryType:UITableViewCellAccessoryNone];
[cell setAccessoryType:UITableViewCellAccessoryCheckmark]; // 'select' the new cell
oldIndexPath=indexPath;
}
}
Hope this works out! :)
Something like this may work:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [self tableView:myTableView cellForRowAtIndexPath:indexPath];
[cell setAccessoryType:UITableViewCellAccessoryCheckmark];
}
To answer the comment below, just push a viewController in the same method like this:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [self tableView:myTableView cellForRowAtIndexPath:indexPath];
[cell setAccessoryType:UITableViewCellAccessoryCheckmark];
// Then push a new view
iPhoneCustomViewController *myVC = [[iPhoneCustomViewController alloc] initWithNibName:#"iPhoneCustomViewController" bundle:nil];
[self.navigationController pushViewController:myVC animated:YES];
[myVC release];
// And deselect the row (if desired)
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}
Did you know that:
1.) UITableView keeps track of the index paths for the rows that have been selected? It's in an array called indexPathsForSelectedRows
2.) UITableView has a flag you can set to make it either single or multiple selection. You can change it by calling the setter setAllowsMultipleSelection:(BOOL).
So, assuming that the table has been set to single selection, we can do the following in the tableView:CellForRowAtIndexPath method ...
-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *simpleTableIdentifier = #"CellIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];
}
[cell setSelectionStyle:UITableViewCellSelectionStyleNone];
[[cell textLabel] setText:#"Some Text"];
NSArray *selectedIndexPaths = [tableView indexPathsForSelectedRows];
if ([selectedIndexPaths containsObject:indexPath]) {
[cell setAccessoryType:UITableViewCellAccessoryCheckmark];
}else{
[cell setAccessoryType:UITableViewCellAccessoryNone];
}
return cell;}
This implementation of CellForRowAtIndexPath will give you a clean checkmark with no gray background when a cell is selected. You will need to set the checkmark in the didSelectRowAtIndexPath delegate method to make sure a cell gets the checkmark the moment it gets selected.
No need to create separate ivars or anything else to keep track of what was or wasn't selected. It's all neatly contained in the UITableView as Apple intended.
UITableViewCell *newCell = [tableView cellForRowAtIndexPath:indexPath];
newCell.accessoryType=UITableViewCellAccessoryCheckmark;
Implement this in didSelectRowAtIndexPath delegate method
From the docs:
The delegate handles selections in this method. One of the things it
can do is exclusively assign the check-mark image
(UITableViewCellAccessoryCheckmark) to one row in a section
(radio-list style). This method isn’t called when the editing property
of the table is set to YES (that is, the table view is in editing
mode). See "Managing Selections" in Table View Programming Guide for
iOS for further information (and code examples) related to this
method.
Here is an example:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath]
cell.UITableViewAccessoryType = UITableViewCellAccessoryCheckmark;
}
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.