I want to get multiple custom texts on cell of UITableView. I want these texts after clicking on a dynamically added button on the cell. I can't use didRowSelectedAtIndex method. I have my own selector which I am executing but I don't know how can I get texts on each cell. Anybody can help me?
Thank
You add a UILabel to the cell's view. Just like you did it with your custom Button.
You can add a UILabel to all cells in advance. If the UIButton on a cell is cklicked, you have to save that state information somewhere (NSArray). When it comes to rendering the cell, you ask the array if the cell at current index should show some text and set it up if so...
If you want immediate rendering call [self.tableView reloadData]
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
if (array at index indicates clicked) {
myCustomCell.label1 = #"foo";
} else {
myCustomCell.label1 = #"bar";
}
}
If you don't like customs cells. You can apply a tag to the label, add the label to the cell and get it from cell by querying it afterwards by that tag.
Make your labels as global variables
Create yur cell as default style cell.
Add your labels to contentView of cell without text.
Add your button.
In the method that button invokes after click set texts to your labels.
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
customLabel1 = [[UILabel alloc] initWithFrame:CGRectMake(5, 5, 50, 20)];
customLabel2 = [[UILabel alloc] initWithFrame:CGRectMake(55, 5, 50, 20)];
[cell.contentView addSubview:customLabel1];
[cell.contentView addSubview:customLabel2];
}
and
- (IBAction) click
{
customLabel1.text = #"YAYA";
customLabel2.text = #"GAGA";
}
You could maybe try creating a custom button class by extending UIButton and add properties to contain references to the NSString objects (or index of the original array where the strings are stored etc).
Then on button click you can cast the sender to your custom button type and simply retrieve the property values.
Related
I have a problem, setting a button to a UITableviewCell.
After viewDidLoad, the button is on the right place. But when I am scrolling down, the button is anyplace else.
Here is my code, I hope you can help me.
Thanks In Advance.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
if (indexPath.section == 0 && indexPath.row == 0 && _isAddImageViewLoad == NO) {
// Add Image Button
UIButton *addImage = [UIButton buttonWithType:UIButtonTypeCustom];
UIImage* image = [UIImage imageNamed:#"AddImage#2x"];
addImage.frame = CGRectMake(110.0f, 10.0f, 110.0f, 110.0f);
[addImage setImage:image forState:UIControlStateNormal];
[cell.contentView addSubview:addImage];
_isAddImageViewLoad = YES;
} else {
NSDictionary *dictionary = [_items objectAtIndex:indexPath.section];
NSArray *array = [dictionary objectForKey:#"data"];
NSString *cellValue = [array objectAtIndex:indexPath.row];
cell.textLabel.text = cellValue;
}
return cell;
}
It is because you are reusing the cells, and the button is getting placed when it shouldn't an easy solution in your else section. Write addImage.hidden = YES; and in your if statement put addImage.hidden = NO;
Just a couple things. If you use "AddImage" it will use the "AddImage#2x" automatically if it's a retina display. I don't think that will solve your issue but it could be causing weirdness.
When a table view cell is scrolled off the view it is "recycled" in a sense. It appears like you are using a bool to exclude the original cell from being loaded again with a button. You may want to use a header to hold your button if you always want it at the "top". You may also want to verify that the button is being removed when the cell is reused. if its not it will show up in the next row that reuses that cell.
On a side note... Buttons don't usually work very well in table view cells because they handle touches in very different ways. It's quite a bit of modification to get them to feel natural but that's another matter.
Hope that helps!
The problem is because of cell reuse. You need to put some code in the else clause to delete the button if it exits. One way to do this, would be to give your button a tag, like:
addImage.tag = 10;
Then in your else clause:
}else{
if (cell viewWithTag:10) [[cell viewWithTag: 10] removeFromSuperview];
...
The problem is because of the dequeue for the cells. The first time the tableview creates the cells, all the cells run through the
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
code. But when the section 0 row 0 is moved off the screen, that cell is pushed into the cell reusable queue.
Now when your tableview needs to display section 0 row 0, it will get a cell from the reuse queue. you will not get the same cell as the first time. So now you might have 2 cells with the button.
What you should do is have different CellIdentifier for section 0 row 0 , and all other sections and rows. Also create the button when creating the cell. So after the first time the tableView creates the cell, you will not be creating the the button everything.
Look at this line of code:
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
This line of code means the UITableViewCells are not created every time. They are re-used as you scroll up and down. Using the code you have above, the UIButton will be created in the correct spot, but then as the cells are re-used, it will create the button in random spots.
One quick way to solve the problem, change the above line of code to simply
UITableViewCell *cell;
I have a UINavigationController full of UITableViews and I use custom cells in a specific one of these.
In tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath I add a UILabel with [cell addSubview:label];
This works great, however if I then go into the detail view, then return back, it duplicates the label. How can I stop this?
Thanks.
The problem is that you are adding a new label every time the cell gets reused and displayed again.
Since you're using a custom cell already, the easiest solution would be to give the cell a UILabel property, and use that instead of adding a new label each time. Specifically, you should only add a new label if you're creating a cell instead of getting a recycled one. Or, you could add a new UILabel only if the property is nil.
Or as an alternative to adding the label in the custom class, just make sure to add the label inside the conditional cell creation. e.g.
UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:ident];
if(cell == nil){
cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:ident] autorelease];
[cell.contentView addSubview:[[[UILabel alloc] init] autorelease]]; // <-------
}
Add a tag to the label, then check if it exists
UILabel *label;
if ([cell viewWithTag:2]){
label = [cell viewWithTag:2];}
else{
label = [[UILabel alloc]init];label.tag = 2;}
I have created a grouped table view like in the image below. but data in the table row , appears and disappears when we scroll up (or) scroll down the page , when we scroll up first 2 rows will go up (beyond the view) then if we scroll down both rows will take same value,, y its so? can any one help me
Thanks in advance.
like following code i am designing the table cell where CustomCellStudentData is class there i am creating like lable frames, text field frames
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
CustomCellStudentData *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[CustomCellStudentData alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];
}
switch(indexPath.section)
{
case 0:
switch (indexPath.row)
{
case 0:
{
tfText[0] = [[UITextField alloc] initWithFrame:CGRectMake(100,10, 200, 40)];
cell.accessoryView = tfText[0];
tfText[0].delegate=self;
tfText[0].placeholder =#"<Student Name>";
cell.primaryLabel.text =#"Student Name: ";
}
break;
case 1:
{
tfText[1] = [[UITextField alloc] initWithFrame:CGRectMake(100,10, 200, 40)];
cell.accessoryView = tfText[1];
tfText[1].delegate=self;
tfText[1].placeholder =#"<Student Age>";
cell.primaryLabel.text =#"Student Age: ";
}
}
}
UITableView reuses the cells so as to not bog down the memory. As soon as the two cells go up, they enter the pool of reusable cells. If the pool is not empty, dequeueReusableCellWithIdentifier: returns a cell from that pool (there is a dependency on the identifier here). As the table view needs cells for the new rows being scrolled in, it gets the cells from the pool and provides it to you for reconfiguration. So, the text field that you attached to the cell when configuring it for row 0 and 1 still remain unless you explicitly remove. Since we don't which cells we are going to get, we should reset all customizations that we do and configure it as a new cell. In this case, irrespective of the cell coming in, you should remove the text field as the accessory view first.
cell = [[[CustomCellStudentData alloc] initWithFrame:CGRectZero reuseIdentifier:nil] autorelease];
What Deepak said is correct.
Adding to his answer, in future, if you add any subView to cell view. Remove from the cell before you add anything on it. Use
for(UIView * view in cell.contentView.subviews){
[view removeFromSuperview]; view = nil;
}
before customizing the cell.
And yes, please increase your acceptance rate. Going back to the questions you asked before and accepting some answers should help.
I want my UITableViewCell to look like the image below where there seems to be two labels. Is this possible without subclassing UITableViewCell?
alt text http://img31.imageshack.us/img31/2764/photoobp.jpg
There are different styles of UITableVieWCell. See here:
https://developer.apple.com/documentation/uikit/uitableviewcell/cellstyle
I think you want to use UITableViewCellStyleValue1.
You can initialise your UITableViewCell with the relevant style:
https://developer.apple.com/documentation/uikit/uitableviewcell/1623276-init
When you use a style that has two labels, you can use the textLabel and detailTextLabel properties to set them, respectively.
You do not need to subclass a UITableViewCell in order to add content to it. Here could be a sample cell generation method with an extra label:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *identifier = #"Identifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:identifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identifier] autorelease];
UILabel *secondLabel = [[UILabel alloc] initWithFrame:cell.textLabel.frame];
secondLabel.textAlignment = UITextAlignmentRight;
secondLabel.tag = 12345;
[cell.contentView addSubview:secondLabel];
}
UILabel *second = [cell viewWithTag:12345];
second.text = #"Second!";
return cell;
}
Let me know if you have any questions. I can clarify some things if needed.
Not sure where u think you see 2 labels...you can set the UILabels number of lines property if you want more lines UILabel ref....Also there is a UITableViewCell type UITableViewCellStyleSubtitle
which contains a detailTextLabel on top of the regular text labels in UITableCell, so you already have a built in cell with 2 text fields, here is a ref ref to UITableViewCell
Its not 2 labels but 2 buttons, you need to add 2 buttons in contentView view of the cell. Or you can create a footer or header View and add these 2 buttons.
We couldn't find a way to animate UIViews inside a UITableCell as an action from a callback.
Suppose in a scenario where you click on a button on the UITableViewCell and it fires off an asynchronous action to download a picture. Suppose further that when the picture is downloaded we want a UIView in the cell to animate the picture to give user a visual feedback that something new is about to be presented.
We couldn't find a way to track down the UIVIew to invoke beginAnimation on because the original cell that the user clicked on might now be used for another row due to the nature of cells being reused when you scroll up and down in the table. In other words we can't keep a pointer to that UITableViewCell. We need to find another way to target the cell and animate it if that row is visible and don't animate if the row is scrolled out of range.
Keep the cell object different from the object being animated so the cell holds a UIView. When the animation callback occurs check to make sure that the UIView still exists and, if it does, animate the changes.
When the cell object gets bumped off the screen and recycled, release the UIView that would have been animated and create a new one. When the animation callback occurs it will have nothing to do because the UIView no longer exists.
A modification of the above is to keep some sort of object in the UIView that your callback can check to see if the animation is still appropriate. This could be some sort of unique identifier for the picture being downloaded. If the identifier changes, no animation is needed. If it matches, do the animation.
EDIT:
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *MyIdentifier = #"MyTableCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MyIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle
reuseIdentifier:MyIdentifier] autorelease];
} else {
UIView *oldViewToAnimate = [cell.contentView viewWithTag:1];
[oldViewToAnimate removeFromSuperview];
}
UIView *viewToAnimate = [[UIView alloc] initWithFrame:CGRectZero]; //replace with appropriate frame
viewToAnimate.tag = 1;
[cell.contentView addSubview:viewToAnimate];
return cell;
}
When you spawn your download process you pass in [cell.contentView viewWithTag:1]. When the download is done, it will update the appropriate view. If the table cell was reused the view will no longer have a superview and will not update the wrong cell.
There are things you can do to make this more efficient but this is the basic idea. If you have a custom UITableViewCell than this will probably look a bit different.
EDIT 2:
To reuse the viewToAnimate objects to make sure that they get updated if their parent cells were recycled, do something like the following:
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *MyIdentifier = #"MyTableCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MyIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle
reuseIdentifier:MyIdentifier] autorelease];
} else {
UIView *oldViewToAnimate = [cell.contentView viewWithTag:1];
[oldViewToAnimate removeFromSuperview];
}
UIView *viewToAnimate = [self viewToAnimateForIndexPath:indexPath];
viewToAnimate.tag = 1;
[cell.contentView addSubview:viewToAnimate];
return cell;
}
viewToAnimateForIndexPath will need to:
Check to see if a viewToAnimate has been created for this indexPath
Create a viewToAnimate if there isn't one
Save a reference to the view that can be looked up by indexPath
Return the viewToAnimate so the table cell can use it
I don't know enough about your data structure to do this for you. Once the download process completes it can call this same method to get the view and animate it.