I am trying to add a customCell which simply will allow me to left align one string, and right align the other. In a previous question someone had suggested the following, but I am having problems getting it to work with my code. Xcode says: RootviewController may not respond to --contentView, and that call [[self contentView] addSubView:item] or [[self contentView] addSubView:rank] will crash my app at runtime
// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];
UILabel *rank = [[UILabel alloc] initWithFrame:CGRectMake(5, 5, 100, 20];
//Mess around with the rects, I am just merely guessing.
[rank setTag:5];
[[self contentView] addSubView:rank];
[rank release];
UILabel *item = [[UILabel alloc] initWithFrame:CGRectMake(110, 5, 220, 20];
//Important
[item setTextAlignment:UITextAlignmentRight];
[item setTag:6];
[[self contentView] addSubView:item];
[item release];
}
UILabel *rank = (UILabel *)[cell viewWithTag:5];
UILabel *item = (UILabel *)[cell viewWithTag:6];
rank = #"leftside";
item = #"rightside";
}
Thanks for any ideas
You should be looking at
[cell.contentView addSubview:item];
[cell.contentView addSubview:rank];
rank.text = #"leftside";
item.text = #"rightside";
One more thing to note here. If your UITableView is scrollEnabled, you will have problems with cellReusability and your labels will get messed up with subsequent scrolls. I would suggest that you subclass UITableViewCells and add those in the layout, and then use the CustomUITableViewCells.
self here is the controller. Instead of making self the receiver, you should be sending contentView to the cell you just created.
Related
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;
}
I have a UITableView with method cellForRowAtIndexPath shown below, the problem is that cellImage only appears after having scrolled completely up (so no rows are visible) and then releasing. The strange thing is that I have identical code in another class for a separate table view and the image appears fine. Any ideas?
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"CellIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
cell.accessoryType = UITableViewCellAccessoryNone;
}
[cell.textLabel setText:[items objectAtIndex:indexPath.row]];
[cell.textLabel setFont:[UIFont fontWithName:#"Helvetica" size:15.0f]];
[cell.textLabel setTextColor:[UIColor whiteColor]];
[cell setBackgroundColor:[[UIColor alloc] initWithRed:117.0/255.0 green:118.0/255.0 blue:121.0/255.0 alpha:1.0]];
[self.tableView setBackgroundView:nil];
[self.tableView setBackgroundView:[[UIView alloc] init]];
[self.view setBackgroundColor:[[UIColor alloc] initWithRed:167.0/255.0 green:169.0/255.0 blue:172.0/255.0 alpha:1.0]];
UIImageView *cellImage = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"next#2x.png"]];
[cell addSubview:cellImage];
[cellImage setFrame:CGRectMake(0, 0, 26, 24)];
[cellImage setCenter:CGPointMake(cell.frame.size.width - 30, cell.frame.size.height/2)];
return cell;
}
[self.tableView setBackgroundView:nil];
[self.tableView setBackgroundView:[[UIView alloc] init]];
The lines dont belong to the method. You call the methods every time you scroll for every cell. Put them in your viewDidLoad method, after you have created your table view.
UIImageView *cellImage = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"next#2x.png"]];
[cell addSubview:cellImage];
These lines are really very BAD and may cause a memory leak.
Everytime you scroll the table view you add a imageview to the cell. Table view reuses the cells. It means when cell is reused, you add a new imageview to the cell. After you scroll more times you have x times imageview on every cell, unless you remove them somewhere in you code.
Other point is, if you want to add some subview to a cell (eg. in init method of the cell) then add it to contenview of the cell like this
[cell.contentView addSubview:someView];
Otherwise your subview may overlap accessory views. And you can have problems when your cell is resized.
I advise you read the guide from the following link:
http://developer.apple.com/library/ios/#documentation/userexperience/conceptual/tableview_iphone/TableViewCells/TableViewCells.html#//apple_ref/doc/uid/TP40007451-CH7-SW1
As captured in many of the comments, there are a number of issues:
Set your view and tableView background in your viewDidLoad method (or via your XIB), not in cellForRowAtIndexPath
Use the cell.imageView property to set a left icon, OR, alternatively, to build a custom cell you would use [cell.contentView addSubview:cellImage]. If you do the latter, you should also add your textLabel in the same manner as a UILabel.
To set the background of a tableview cell, use this delegate method:
-(void) tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell*)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
[cell setBackgroundColor:[[UIColor alloc] initWithRed:117.0/255.0 green:118.0/255.0 blue:121.0/255.0 alpha:1.0]];
}
though for efficiency you should instantiate this UIColor once in your viewcontroller and set it as [cell setBackgroundColor:self.cellBackground];
The problem you are facing is due to reuseIdentifier for cell.
Also you are creating Imageview everytime cellForRowAtIndexPath is executed.
i will suggest two solution here for you.
1st Option :- just replace this code :
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:nil];
cell.accessoryType = UITableViewCellAccessoryNone;
}
this is not proper way when you are dealing with dynamic images, means you are downloading thumbnail from server and data content is more, if it's small and static data then it's fine for you.
2nd Option :- just use this formatted code this will not create imageview everytime just use object from current cell with tag.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"CellIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
cell.accessoryType = UITableViewCellAccessoryNone;
UIImageView *cellImage = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 26, 24)];
cellImage.tag = 88;
[cell addSubview:cellImage];
[cellImage setCenter:CGPointMake(cell.frame.size.width - 30, cell.frame.size.height/2)];
}
[cell.textLabel setText:[items objectAtIndex:indexPath.row]];
[cell.textLabel setFont:[UIFont fontWithName:#"Helvetica" size:15.0f]];
[cell.textLabel setTextColor:[UIColor whiteColor]];
[cell setBackgroundColor:[[UIColor alloc] initWithRed:117.0/255.0 green:118.0/255.0 blue:121.0/255.0 alpha:1.0]];
[self.tableView setBackgroundView:nil];
[self.tableView setBackgroundView:[[UIView alloc] init]];
[self.view setBackgroundColor:[[UIColor alloc] initWithRed:167.0/255.0 green:169.0/255.0 blue:172.0/255.0 alpha:1.0]];
UIImageView *cellImage = (UIImageView *)[cell viewWithtag:88];
cellImage.image = [UIImage imageNamed:#"next#2x.png"];
}
Fixed using the following code:
UIImageView *cellImage = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"next#2x.png"]];
[cell setAccessoryView:cellImage];
i am new programmer of iphone App... i have 7 labels and 1 imageView in first cell of table view......
i write this code for that..... this work satisfactory...(may be it take times when scroll)
please tell me ...this is the right way to do this task or not....?
if not please...tell me ..the right way...
thanks in advance
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:[NSString stringWithFormat:#"Cell %i",indexPath.section]];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:[NSString stringWithFormat:#"Cell %i",indexPath.section]] autorelease];
}
if(indexPath.row==0)
{
CGRect frame=CGRectMake(120,10, 80, 40);
UILabel *label1=[[UILabel alloc]init];
label1.frame=frame;
label1.text=#"first label";
[cell.contentView addSubview:label1];
[label1 release];
CGRect frame2=CGRectMake(200,10, 80, 40);
UILabel *label2=[[UILabel alloc]init];
label2.frame=frame2;
label2.text=#"second label";
[cell.contentView addSubview:label2];
[label2 release];
and so on.......
}
else if(indexPath.row==1)
{
//add four labels for this cell here......
}
return cell;
}
When you are reusing cell you don't need to create labels second time:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:[NSString stringWithFormat:#"Cell %i",indexPath.section]];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:[NSString stringWithFormat:#"Cell %i",indexPath.section]] autorelease];
if(indexPath.row==0)
{
CGRect frame=CGRectMake(120,10, 80, 40);
UILabel *label1=[[UILabel alloc]init];
label1.frame=frame;
label1.text=#"first label";
label1.tag = 1001;
[cell.contentView addSubview:label1];
[label1 release];
CGRect frame2=CGRectMake(200,10, 80, 40);
UILabel *label2=[[UILabel alloc]init];
label2.frame=frame2;
label2.text=#"second label";
label2.tag = 1002;
[cell.contentView addSubview:label2];
[label2 release];
and so on.......
}
}
if(indexPath.row==0)
{
UILabel *label1=[cell viewWithTag:1001];
label1.text=#"first label";
UILabel *label2=[cell viewWithTag:1002];
label2.text=#"second label";
and so on.......
}
return cell;
}
I'm accessing previously created labels using there tag value.
I think, it will be much easier to design such a complicated cell in InterfaceBuilder. If you're using Storyboards, you can design custom cells right away in your table view. If you're using xibs, you can create a nib that will have a custom UITableViewCell instead of the table view, UIViewController as owner and declare subclass of UITableViewCell in your project. That should make your sufferings much easier =)
I am using a table view in one of myapplications. In that number of sections are one and number of rows are 20. And i want to place the image and two lables in that every row. So to fill up the rows,i written the below code in CellForrowIndexpath method
- (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];
}
int i=indexPath.row;
if (indexPath.row==i)
{
cell = [self getCellContentView:CellIdentifier];
UILabel *lblTemp1 = (UILabel *)[cell viewWithTag:1];
UILabel *lblTemp2 = (UILabel *)[cell viewWithTag:2];
//UILabel *lblTemp3 = (UILabel *)[tableCell viewWithTag:3];
lblTemp1.text = [ctrycodearray objectAtIndex:indexPath.row];
lblTemp2.text = #"Alert";
UIImageView *img=[[UIImageView alloc]initWithFrame:CGRectMake(0,0, 100, 30)];
img.image=[UIImage imageNamed:#"thumb_mdpi.png"];
//NSString *cellValue1 = [default1 stringForKey:#"keyToRepeatString"];
//repeatlbl.text=cellValue1;
//[img release];
[cell.contentView addSubview:img];
return cell;
}
In the getCellContentView method i declared the two lables.After executing this one i got the error.This cellForRowAtIndexPath method executed 6 or 7 times and print the 6 or 7 rows>but if move to top the below errowill occured.So please tell me how to solve this.
It is always better to use custom UITableViewCell for these kind of things.
Ref: Apple doc.
Try as per this doc & if u hav any problem, pl. post that here.
Edit: Don't need to read the whole doc. Just have a look at Listing 5-3 Adding subviews to a cell’s content view in that link.
I put multiple UILabels inside every cell in a UITableView instead of a single cell.textLabel.text. I then use reloaddata to put new uilabels. How do i get rid of the old labels ?
edit: If i put 5 labels in a cell then reload the cell using only 2 labels, there are 3 more labels left over from the last time i called cellForRowAtIndexPath.
If i use viewWithTag like Goldeen said, i can reuse old labels but can i remove labels i dont want from memory ?
edit:
this is my method
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
MyTableCell *cell = (MyTableCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[MyTableCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
UILabel *label = [[[UILabel alloc] initWithFrame:CGRectMake(j*50.0, 0, 49.0,logicTable.rowHeight)] autorelease];
label.tag = 1;
label.text = [NSString stringWithFormat:#"ABC"];
label.textAlignment = UITextAlignmentCenter;
label.autoresizingMask = UIViewAutoresizingFlexibleRightMargin |
UIViewAutoresizingFlexibleHeight;
[cell.contentView addSubview:label];
return cell;
}
What it sounds like you are doing is, in your cellForRowAtIndexPath method, you are setting up your UITableViewCells with some labels in them and each time, you are making the labels from scratch. What you should be doing is, setting up the labels if you are making a new cell, and then setting the values on the labels outside of this to fully utilize the ability to reuse table view cells to improve performance of scrolling the table view.
The key method is -viewWithTag: which, along with the tag property on UIView you can use to find a specific subview.
A little sample code:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"MyCellIdentifier";
UITableViewCell *cell = (WHArticleTableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
UILabel *firstLabel = nil;
UILabel *secondLabel = nil;
UILabel *thirdLabel = nil;
if (cell == nil)
{
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
firstLabel = [[[UILabel alloc] initWithFrame: CGRectMake(0.0, 0.0, 20.0, 20.0)] autorelease];
firstLabel.tag = 1;
[cell addSubview:firstLabel];
secondLabel = [[[UILabel alloc] initWithFrame: CGRectMake(20.0, 0.0, 20.0, 20.0)] autorelease];
secondLabel.tag = 2;
[cell addSubview:secondLabel];
thirdLabel = [[[UILabel alloc] initWithFrame: CGRectMake(40.0, 0.0, 20.0, 20.0)] autorelease];
thirdLabel.tag = 3;
[cell addSubview:thirdLabel];
}
else
{
firstLabel = (UILabel *)[cell viewWithTag:1];
secondLabel = (UILabel *)[cell viewWithTag:2];
thirdLabel = (UILabel *)[cell viewWithTag:3];
}
firstLabel.text = #"First Label's Text Here";
secondLabel.text = #"Second Label's Text Here";
thirdLabel.text = #"Third Label's Text Here";
return cell;
}