I am a newbie to iPhone programming. I am stuck in a situation. I need to change the UITableViewCell image (on the left side) through calling an action from UIBarButtonItem fromt he UIToolBar. I have searched through internet, but can't find any appropriate solution.
Any Help regarding this would be appreciated.
Here is a sample code for customizing cell imageView.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *CellIdentifier = #"MyTableViewCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle
reuseIdentifier:CellIdentifier];
[cell.imageView setBounds:CGRectMake(0, 0, 30, 30)];
[cell.imageView setClipsToBounds:YES];
[cell.imageView setFrame:CGRectMake(0, 0, 30, 30)];
[cell.imageView setContentMode:UIViewContentModeScaleAspectFit];
}
// customize cell
[cell.imageView setImage:**your_image**];
return cell;
}
With the [tableview cellForRowAtIndexPath:] method you can access a cell at a specific row. When you have accessed that you can reach the image by cell.imageView. Have a look at this:
- (IBAction)barbuttonPressed
{
UITableViewCell *cell = [self.tableView [NSIndexPath indexPathForRow:row inSection:section];
cell.imageView = .....
}
Replace row and section with appropriate.
Related
I have a UITableView with heavy data. And I create UITableViewCell every time just like:
UITableViewCell *cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:strCellIdentifier];
And after that I add many UIView's as a subView to UITableViewCell for e.g
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button addTarget:self action:#selector(onDocumentLogoTapped:) forControlEvents:UIControlEventTouchUpInside];
button.frame = imageRect;
button.tag = indexPath.row;
[cell addSubview:button];
And like that I also add UIImageView. Problem is that my UITableView becomes very slow and application crashes sometime because of memory issue.
Could anyone suggest me proper way of using UITableViewCell when adding subView to it?
Use this in cellForRowAtIndexPath method :
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
}
Do like as following:
Before adding subview, First remove previous subviews
for(UIView *sv in [cell.contentView subViews])
{
[sv removefromsuperview];
}
[cell.contentView addSubview:button];
Hope this Help!
I think it will be better if you go for custom cell then you can use this method as
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
NSArray *nib;
static NSString *cellIdentifier= #"cell";
UITableViewCell *theCell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if(theCell== nil)
{
{
nib = [[NSBundle mainBundle] loadNibNamed:#"<your custom cell xib name>" owner:self options:nil];
}
theCell = [nib objectAtIndex:0];
theCell.selectionStyle = UITableViewCellSelectionStyleBlue;
}
UIImageView *imageView=(UIImageView*)[[theCell contentView] viewWithTag:101];
//assuming it has a image view with tag 101 you can use any thing
}
I am creating custom cell contain UILabel , UIImageView ,using constant tag for UILabel , UIImageView using dynamic tag, the table have 11 cells, the first 7 cells loading correctly, the 8, 9, 10, 11 cell image view change when I am changing the 1, 2, 3, 4, cell respectively in the table, also the tags are same in the cells, I am using the images to check box in table,UITapGestureRecognizer used to change imageview in the table,
I am using this code.....
- (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] ;
cell.selectionStyle=UITableViewCellSelectionStyleGray;
cell.accessoryType=UITableViewCellAccessoryDisclosureIndicator;
UIImageView *imageview=[[UIImageView alloc]initWithFrame:CGRectMake(5, 12, 20, 20)];
imageview.tag=n;
[cell.contentView addSubview:imageview];
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tabimage:)];
imageview.userInteractionEnabled=YES;
[imageview addGestureRecognizer:tap];
imageview.image=[UIImage imageNamed:#"img1.jpeg"];
UILabel *titleLabel=[[UILabel alloc]initWithFrame:CGRectMake(30, 2, 260,26)];
titleLabel.tag=222;
titleLabel.backgroundColor=[UIColor clearColor];
[cell.contentView addSubview:titleLabel];
UILabel *dateLabel=[[UILabel alloc]initWithFrame:CGRectMake(30, 31, 260, 13)];
dateLabel.tag=333;
dateLabel.font=[UIFont systemFontOfSize:10];
dateLabel.backgroundColor=[UIColor clearColor];
[cell.contentView addSubview:dateLabel];
}
UIImageView *imageview1=(UIImageView*)[cell.contentView viewWithTag:n];
if([array containsObject:[NSNumber numberWithInt:imageview1.tag]]) {
imageview1.image=[UIImage imageNamed:#"img2.jpeg"];
} else {
imageview1.image=[UIImage imageNamed:#"img1.jpeg"];
}
UILabel *titlelable=(UILabel*)[cell.contentView viewWithTag:222];
titlelable.text=[task objectAtIndex:indexPath.section];
NSLog(#"%i",indexPath.section);
UILabel *dateLabel=(UILabel*)[cell.contentView viewWithTag:333];
dateLabel.text=[date objectAtIndex:indexPath.section];
n++;
return cell;
}
- (void)tabimage:(id)sender {
UIImageView *iv=(UIImageView *)[sender view];
int i=iv.tag;
NSLog(#"------------%i",i);
if (iv.image==[UIImage imageNamed:#"img1.jpeg"]) {
iv.image= [UIImage imageNamed:#"img2.jpeg"];
[array addObject:[NSNumber numberWithInt:i]];
} else {
iv.image= [UIImage imageNamed:#"img1.jpeg"];
[array removeObject:[NSNumber numberWithInt:i]];
}
}
You should change your cell identifier from static to dynamic that will solve your problem.
You should replace this
static NSString *CellIdentifier =#"Cell";
UITableViewCell *cell = [tableview dequeueReusableCellWithIdentifier:CellIdentifier];
with this
UITableViewCell *cell = [tableview dequeueReusableCellWithIdentifier:[NSString stringWithFormat:#"%d %d"], indexPath.row, indexPath.section];
Whatever problem you see, use of that "n" is most probably the problem. There is no good reason to use a shared variable to tag (and retrieve) views on table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath is called many times, it may be called several times for the same cell, and sometimes it finds a cell to reuse, and sometimes not.
I have of course no idea what n is, and how you use it elsewhere in your code, but you change it with every call here, and you cannot make assumptions when this method is called, so it's worthless.
You know for sure that every cell has one image with that tag, but if it will ever be accessible after the first run through this method or not is totally undefined, so with every reuse you basically get random behavior (either a fresh new cell or a reused one with a tag you don't know).
Ask yourself (or maybe at SO in another question): What are you trying to accomplish here?
i am getting solution for my app,
to using dynamic cell identifier in my code
NSString *CellIdentifier =[NSString stringWithFormat:#"%i-%i", indexPath.section,indexPath.row];
I suggest subclass the UITableViewCell add there all your custom elements, create setters for it. And in cellForRowAtIndexPath just call your setters.
As you are setting tag to imageview in if(cell == nil) block means tag will be set when cell is getting created. In your case 7 cells are getting created after that cells are reused by dequeuing. Hence for 8 onwards previously created cells will be used. This is why your tags are same as 1,2,3...for 8,9,10...cells.
Well, Alex suggested standard way to do it. But if you have not used custom cells yet, you can try this-
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier =#"Cell";
UITableViewCell *cell = [tableview dequeueReusableCellWithIdentifier:CellIdentifier];
UIImageView *imageview = nil;
if(cell){
for (UIView *view in cell.contentView.subviews){
if([view isKindOfClass:[UIImageView class]]){
imageview = (UIImageView*)view;
break;
}
}
}
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] ;
cell.selectionStyle=UITableViewCellSelectionStyleGray;
cell.accessoryType=UITableViewCellAccessoryDisclosureIndicator;
imageview=[[UIImageView alloc]initWithFrame:CGRectMake(5, 12, 20, 20)];
[cell.contentView addSubview:imageview];
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tabimage:)];
imageview.userInteractionEnabled=YES;
[imageview addGestureRecognizer:tap];
imageview.image=[UIImage imageNamed:#"img1.jpeg"];
UILabel *titleLabel=[[UILabel alloc]initWithFrame:CGRectMake(30, 2, 260,26)];
titleLabel.tag=222;
titleLabel.backgroundColor=[UIColor clearColor];
[cell.contentView addSubview:titleLabel];
UILabel *dateLabel=[[UILabel alloc]initWithFrame:CGRectMake(30, 31, 260, 13)];
dateLabel.tag=333;
dateLabel.font=[UIFont systemFontOfSize:10];
dateLabel.backgroundColor=[UIColor clearColor];
[cell.contentView addSubview:dateLabel];
}
imageview.tag=n;
if([array containsObject:[NSNumber numberWithInt:imageview.tag]]) {
imageview.image=[UIImage imageNamed:#"img2.jpeg"];
} else {
imageview.image=[UIImage imageNamed:#"img1.jpeg"];
}
UILabel *titlelable=(UILabel*)[cell.contentView viewWithTag:222];
titlelable.text=[task objectAtIndex:indexPath.section];
NSLog(#"%i",indexPath.section);
UILabel *dateLabel=(UILabel*)[cell.contentView viewWithTag:333];
dateLabel.text=[date objectAtIndex:indexPath.section];
n++;
return cell;
}
So I had the following code:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSString *CellIdentifier = #"FriendsCell";
FriendData * fd = [self.friendsDataSource_ objectAtIndex:indexPath.row];
UITableViewCell *cell = (UITableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
}
[cell.imageView setImageWithURL:[NSURL URLWithString:fd.imageUrl_]];
[cell.imageView setFrame:CGRectMake(0, 0, 30, 30)];
[cell.textLabel setText:fd.name_];
return cell;
}
However, I am not seeing the imageView in the cell. What am I doing wrong?
I got the same problem with SDImageCache as well. My solution is to put a placeholder image with the frame size you want.
UIImage *placeholder = [UIImage imageNamed:#"some_image.png"];
[cell.imageView setImage:placeholder];
[cell.imageView setImageWithURL:[NSURL URLWithString:fd.imageUrl_]];
1) Set Image with URL is not an iOS method. It's something custom and that may be the problem. But until you publish it can't help there.
2) I think cell.imageView will ignore "setFrame". I can't get that to work in any of my table cells using an image. It always seems to default to width of the image.
3) Typically you set the image using cell.imageView.image = your_Image. The ImageView is READONLY and probably the ImageView frame is private.
4) I think you are going to need to create a custom cell of your own.
Usage of a method with placeholder will fix it.
[cell.imageView setImageWithURL:[NSURL URLWithString:fd.imageUrl_]placeholderImage:[UIImage imageNamed:#"placeholder"]];
you need to return cell at the end of the method
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSString *CellIdentifier = #"FriendsCell";
FriendData * fd = [self.friendsDataSource_ objectAtIndex:indexPath.row];
UITableViewCell *cell = (UITableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
}
[cell.imageView setImageWithURL:[NSURL URLWithString:fd.imageUrl_]];
[cell.imageView setFrame:CGRectMake(0, 0, 30, 30)];
[cell.textLabel setText:fd.name_];
return cell;
}
my app has a bug, and i believe its because I'm not reseting the cells content. The apple docs say
The table view’s data source implementation of tableView:cellForRowAtIndexPath: should always reset all content when reusing a cell.
Could someone please explain how to do this, or point me to a tutorial? Thank you in advance!
My cellForRow
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath: (NSIndexPath *)indexPath
{
static NSString *identifier = #"Cell";
cell = [tableView dequeueReusableCellWithIdentifier:identifier];
if (cell == nil)
{
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identifier] autorelease];
addBtn = [[UIButton alloc]init];
addBtn =[UIButton buttonWithType:UIButtonTypeRoundedRect];
[addBtn setFrame:CGRectMake(220,10,25,55)];
[addBtn addTarget:self action:#selector(addLabelText:) forControlEvents:UIControlEventTouchUpInside];
[addBtn setTitle:#"+" forState:UIControlStateNormal];
[addBtn setEnabled:YES];
[cell addSubview:addBtn];
subBtn = [[UIButton alloc]init];
subBtn=[UIButton buttonWithType:UIButtonTypeRoundedRect];
[subBtn setFrame:CGRectMake(260,10,25,55)];
[subBtn addTarget:self action:#selector(subtractLabelText:) forControlEvents:UIControlEventTouchUpInside];
[subBtn setTitle:#"-" forState:UIControlStateNormal];
[subBtn setEnabled:YES];
[cell addSubview:subBtn];
}
//cellText.hidden=!self.editing;
cell.textLabel.textColor = [UIColor orangeColor];
[cell setSelectionStyle:UITableViewCellSelectionStyleNone];
cell.imageView.image = [imageArray objectAtIndex:indexPath.row];
cell.textLabel.text = [number objectAtIndex:indexPath.row];// <------ Is this line in the right place?
cell.textLabel.text = #"1"; // <---- Is this line in the right place?
return cell;
}
It's pretty simple. You provide the call cellForRowAtIndexPath in your code. In it, you either provide a brand new cell, or you reuse a cell that the OS has chucked into memory. Basically, you code looks like this:
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
// Configure the cell...
[[cell textLabel] setText:[pickerData objectAtIndex:indexPath.row]];
cell.accessoryType = (indexPath.row == currentValueOfIndex ) ?
UITableViewCellAccessoryCheckmark : UITableViewCellAccessoryNone;
return cell;
The part under the comment // Configure the cell is where you have to reset your cells content. Since it can either be a new cell, or a recycled cell, it will either have no information, or the information from another cell where it was recycled from. In both cases, you provide the cell's text and accessories and anything else you want to use each time the cell is called. Basically, it's a callback to you to provide a cell, either a brand new one, or a recycled one, and you have to stuff the right info for the cell it's going to be (based on the index path). Hope I made this clear enough.
If you're adding views programmatically to the cell, you should do the following for cleaning them:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"CellID";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
for (UIView * v in cell.contentView.subviews) {
[v removeFromSuperview]
}
//Configure your cell
return cell;
}
See the comments in the code below...
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"CellID";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
// this is where you want to configure your generic cell
// for example, if EVERY cell needs to have a disclosure indicator, you could do
cell.accessoryType = UITableViewAccessoryTypeDisclosurseIndicator;
}
// this is where you want to put code that would or could be unique to a cell
// for example, if you wanted to put the row number you could do:
cell.textLabel.text = [NSString stringWithFormat:#"%d", indexPath.row];
// you would put this here and not in the above if statement because the value of the textLabel changes for different cells
return cell;
}
I am having a problem setting a UIImageView or UIView on the cell of the Grouped table on the iPhone.
For this I am using this code
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *SimpleTableIdentifier = #"SimpleTableIdentifier";
NSArray *listData =[self.tableContents objectForKey:[self.sotreKeys objectAtIndex:[indexPath section]]];
UITableViewCell * cell = [tableView
dequeueReusableCellWithIdentifier:SimpleTableIdentifier];
if(cell == nil) {
cell = [[[UITableViewCell alloc]
initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:SimpleTableIdentifier] autorelease];
}
if(indexPath.section == 1 && indexPath.row ==1)
{
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(240, 14, 40, 40)];
imageView.image = [UIImage imageNamed:[NSString stringWithFormat:#"Back.png",nil]];
[cell.contentView addSubview:imageView];
[imageView release];
}
NSUInteger row = [indexPath row];
cell.textLabel.text = [listData objectAtIndex:row];
return cell;
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}
But it is not placed on the cell . When ever I select the row it will display for that time only, what is the problem?
Does anyone have any idea what the problem is. I think the image is getting overwritten by the cell .
Thanks in advance
try making
cell.accessoryType = UITableViewCellAccessoryNone;
It seems that you are adding image on accessory view.
If yes, you can add cell.accessoryView = imageView;
I do have some ideas of what might be happening.
You are adding an image view to the contentView then you are setting the text of the textLabel which is a part of the contentView and is probably sitting on top of the image. Try this and see if you can at least see your image on the left side.
cell.imageView.image = [UIImage imageNamed:#"Back.png"];
Now when you dequeue cells you need to remember that all the views you added last time you created the cell are still there, so as you scroll you will just be stacking back buttons on top of each other.
Also the following line [tableView deselectRowAtIndexPath:indexPath animated:YES]; is dead code because it occurs after a return statement. You might want to place that in the delegate call – tableView:willDisplayCell:forRowAtIndexPath:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *SimpleTableIdentifier = #"SimpleTableIdentifier";
NSArray *listData =[self.tableContents objectForKey:[self.sotreKeys objectAtIndex:[indexPath section]]];
UITableViewCell * cell = [tableView dequeueReusableCellWithIdentifier:SimpleTableIdentifier];
if(cell == nil) {
cell = [[[UITableViewCell alloc]
initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:SimpleTableIdentifier] autorelease];
}
if(indexPath.section == 1 && indexPath.row ==1)
{
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(240, 14, 40, 40)];
imageView.image = [UIImage imageNamed:#"Back.png"];
[cell.contentView addSubview:imageView];
[imageView release];
}
cell.textLabel.text = [listData objectAtIndex:indexPath.row];
return cell;
}
Make sure that your image is named "Back.png" not "back.png" because the iOS on the phone is key sensitive.