Edit----- i done the same code on english record scrolling speed remain fast as usual and its working fine, but when i am fetching Arabic data scrolling is slow again. is this a problem with arabic data???
I have records of about 100 and my tableview scrolling is very slow. can anyone tell me what is wrong with this code, and why iam getting slow scrolling?
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
GreetingAppDelegate *appdelegate = (GreetingAppDelegate *)[[UIApplication sharedApplication]delegate];
DBSetter *product = (DBSetter *)[appdelegate.myrecords objectAtIndex:indexPath.row];
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
cell.textLabel.font=[UIFont fontWithName:#"Arial" size:16.0];
}
CGRect a=CGRectMake(8, 0, 307, 59);
UIImageView *aImg=[[UIImageView alloc] initWithFrame:a];
UIImageView *bImg=[[UIImageView alloc] initWithFrame:a];
//if(indexPath.row%2==0)
aImg.image=[UIImage imageNamed:#"cell-arrow.png"];
//else {
// aImg.image=[UIImage imageNamed:#"CellHighlight.png"];
//}
bImg.image=[UIImage imageNamed:#"cell-arrow-h.png"];
[aImg setContentMode:UIViewContentModeScaleToFill];
[bImg setContentMode:UIViewContentModeScaleToFill];
cell.backgroundView=aImg;
cell.selectedBackgroundView=bImg;
[aImg release];
[bImg release];
NSString *tempStr=[NSString stringWithFormat:#"%#",product.tempdesc];
//int stringlength=[tempStr length];
//[[tempStr stringByReplacingOccurrencesOfString:#"<Dear User>" withString:#" "] substringWithRange:NSMakeRange(0, 20)];
//if (stringlength >20) {
//cell.textLabel.text = [NSString stringWithFormat:#"%#...", [[tempStr stringByReplacingOccurrencesOfString:#"<Dear user>" withString:#""] substringWithRange:NSMakeRange(0, 30)]];
//}
//else {
cell.textLabel.text = tempStr;
//}
if(appdelegate.lang==2)
{
[cell setTextAlignment:UITextAlignmentRight];
aImg.transform = CGAffineTransformMakeScale(-1, 1);
bImg.transform = CGAffineTransformMakeScale(-1, 1);
}
return cell;
}
A posible cause could be you're creating the imageView's outside the cell creation block. Try this
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
cell.textLabel.font=[UIFont fontWithName:#"Arial" size:16.0];
CGRect a=CGRectMake(8, 0, 307, 59);
UIImageView *aImg=[[UIImageView alloc] initWithFrame:a];
UIImageView *bImg=[[UIImageView alloc] initWithFrame:a];
aImg.image=[UIImage imageNamed:#"cell-arrow.png"];
bImg.image=[UIImage imageNamed:#"cell-arrow-h.png"];
[aImg setContentMode:UIViewContentModeScaleToFill];
[bImg setContentMode:UIViewContentModeScaleToFill];
cell.backgroundView=aImg;
cell.selectedBackgroundView=bImg;
[aImg release];
[bImg release];
}
First thing I see: you're not taking advantage of the recycling!
Do as much as possible in the if (cell == nil) block. Avoid creating image views and other things like that each time an item scroll.
The only meaningful code for recycled cells I see is the cell.textLabel.text = tempStr; line.
Have you tried making a custom TableViewCell with that image as background? You can change the background upon select in the setSelected function of the custom TableViewCell.
Thanks every one for your replies... i just figure out it my self. i just use length and range to make it works. the code that i used is as follow, for the one who might suffer same problem.
NSString *tempStr=[NSString stringWithFormat:#"%#",product.tempdesc];
int stringlength=[tempStr length];
if (stringlength >20) {
cell.textLabel.text = [NSString stringWithFormat:#"%#...", [[tempStr stringByReplacingOccurrencesOfString:#"<Dear user>" withString:#""] substringWithRange:NSMakeRange(0, 30)]];
}
else {
cell.textLabel.text = tempStr;
}
Related
I have table view that showing hotels and if they favorite or not. If hostel are favorite, in hostels's row accessory view I placed image of favorite. But the image not showed only at target's hostel. I placed randomly in other cells in the tableView. Here is the code:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithFrame:CGRectMake(0, 0, 320, 50) reuseIdentifier:CellIdentifier] autorelease];
}
// Set up the cell...
//First get the dictionary object
NSDictionary *dictionary = [listOfItems objectAtIndex:indexPath.section];
NSArray *array = [dictionary objectForKey:#"Countries"];
NSString *cellValue = [array objectAtIndex:indexPath.row];
cell.textLabel.text = cellValue;
if (![favorites count] == 0) {
if ([favorites containsObject:[array objectAtIndex:indexPath.row]]) {
NSUInteger indexx = [favorites indexOfObject:cellValue];
if ([[favorites objectAtIndex:indexx] isEqual:cellValue]) {
// here is the image view
UIImageView *imageView = [[UIImageView alloc] init];
[imageView setImage:[UIImage imageNamed:#"small_ItsMyFavorite.png"]];
imageView.frame = CGRectMake(276, 0, 50, 50);
[cell addSubview:imageView];
[imageView release];
}
}
}
}
}
return cell;
}
I am searching and searching, what is the problem?
Since UITableView is reusing cells your design has some problems.
Your adding an UIImageView to the cell, even when it is reused, so when for instance you have 50 rows and you scroll all the way down, each time a cell is reused, you are adding an UIImageView to the cell. And so flushing the memory.
Better would be to subclass UITableViewCell in which you add the UIImageView. Do not forget to override the prepareForReuse method where you would set the image of your UIImageView to nil
Since UITableViewCell objects are recycled, you need to add an else branch to clear off the image when the hostel is not favorite. As you currently have it, a cell that has been used to display a favorite once would contain an image forever.
if ([[favorites objectAtIndex:indexx] isEqual:cellValue]) {
// here is the image view
UIImageView *imageView = [[UIImageView alloc] init];
[imageView setImage:[UIImage imageNamed:#"small_ItsMyFavorite.png"]];
imageView.frame = CGRectMake(276, 0, 50, 50);
[cell addSubview:imageView];
[imageView release];
} else {
// Find the UIImageView in the subviews of your cell,
// and remove it from superview.
}
you must do something like this
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithFrame:CGRectMake(0, 0, 320, 50) reuseIdentifier:CellIdentifier] autorelease];
}
else
{
[[cell.contentView viewWithTag:999] removeFromSuperView];
}
// Set up the cell...
//First get the dictionary object
NSDictionary *dictionary = [listOfItems objectAtIndex:indexPath.section];
NSArray *array = [dictionary objectForKey:#"Countries"];
NSString *cellValue = [array objectAtIndex:indexPath.row];
cell.textLabel.text = cellValue;
if (![favorites count] == 0) {
if ([favorites containsObject:[array objectAtIndex:indexPath.row]]) {
NSUInteger indexx = [favorites indexOfObject:cellValue];
if ([[favorites objectAtIndex:indexx] isEqual:cellValue]) {
// here is the image view
UIImageView *imageView = [[UIImageView alloc] init];
[imageView setImage:[UIImage imageNamed:#"small_ItsMyFavorite.png"]];
imageView.frame = CGRectMake(276, 0, 50, 50);
imageView.tag = 999; // for example
[cell addSubview:imageView];
[imageView release];
}
}
}
}
}
return cell;
}
I am trying to implement UITableview based application. In my tableView their is 10 Section and each section having one row.
I want implement each section have Different type of ContentView(1-8 same ContentView 9th section Different ContentView). I did this code For that.
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 10;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 1;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier1 = #"Cell1";
static NSString *CellIdentifier2 = #"Cell2";
UITextField *textField;
UITextView *textView;
NSUInteger section=[indexPath section];
if(section == 9){
UITableViewCell *cell=[self.tableView cellForRowAtIndexPath:indexPath];
//UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier1];
if(cell==nil){
cell=[[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier1]autorelease];
textView=[[UITextView alloc]initWithFrame:CGRectMake(5, 5, 290, 110)];
[textView setBackgroundColor:[UIColor scrollViewTexturedBackgroundColor
]];
[textView setTag:([indexPath section]+100)];
[cell.contentView addSubview:textView];
}else{
textView=(UITextView*)[cell.contentView viewWithTag:([indexPath section]+100)];
}
return cell;
}else {
UITableViewCell *cell=[self.tableView cellForRowAtIndexPath:indexPath];
// UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier2];
if(cell==nil){
cell=[[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier2]autorelease];
textField=[[UITextField alloc]initWithFrame:CGRectMake(5, 5, 290, 50)];
[textField setBackgroundColor:[UIColor scrollViewTexturedBackgroundColor]];
[textField setTag:([indexPath section]+100)];
[cell.contentView addSubview:textField];
}else{
textField=(UITextField*)[cell.contentView viewWithTag:([indexPath section]+100)];
}
return cell;
}
return nil;
}
My problem are:
1. After type some thing in the UITextField/UITextView i am scrolling in the UITableView. that time all data in the UITableViewCell(UITextField/UITextView) was lose, except last cell data.
2. If i create cell
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
Instead of
UITableViewCell *cell=[self.tableView cellForRowAtIndexPath:indexPath];
Data will repeating . How can i over come this problem?
This line:
UITableViewCell *cell=[self.tableView cellForRowAtIndexPath:indexPath];
Should never appear in your data source cellForRowAtIndexPath method.
Apart from that, your code is OK, except that you are not setting the text field value anywhere. You need a model (such as an array of strings for the 10 textfield values). This model should be updated when the textfields are edited, and in your method above you copy the value back out of the model and into the textfield's text property:
textfield.text = [self.modelArray objectAtIndex:indexPath.section];
The table pools and reuses cells in an unpredictable fashion, so that subview of a cell that just scrolled off the bottom might reappear next at the top, or might be disposed of.
This is why you saw it partially work. The cell's subviews work okay until their cell gets reused or unloaded, then things move to the wrong place or data disappears.
The solution is that your table's datasource needs to hold onto it's own data. This is usually an array representing your model. Your case is a little unusual because you are using the text controls in your table as inputs, rather than display, which is more typical.
I suggest doing it like this:
// in #interface
#property (nonatomic, retain) NSMutableArray *sections;
// in #implementation
#synthesize sections=_sections;
// at some point before the view appears
self.sections = [NSMutableArray array];
for (int i=0; i<10; i++) {
UIControl *textControl;
if (i<9) {
textControl=[[UITextView alloc]initWithFrame:CGRectMake(5, 5, 290, 110)];
} else {
textControl=[[UITextField alloc]initWithFrame:CGRectMake(5, 5, 290, 50)];
}
[textControl setBackgroundColor:[UIColor scrollViewTexturedBackgroundColor]];
[textControl setTag:i+100];
[sections addObject:textControl];
[textControl release];
}
Now your cellForRowAtIndexPath is a little simpler:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier1 = #"Cell1";
static NSString *CellIdentifier2 = #"Cell2";
NSUInteger section=[indexPath section];
if(section == 9) {
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier1];
if(cell==nil) {
cell=[[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier1]autorelease];
}
} else {
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier2];
if(cell==nil) {
cell = [[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier2]autorelease];
}
}
// who knows what subview this cell has? it might not have one, or it might have the wrong one
// just clean it up to be certain
for (UIView *view in cell.subviews) {
[view removeFromSuperView];
}
// get the textControl we set up for _this_ section/cell
UIControl *textControl = [self.sections objectAtIndex:section];
// now we have a fresh cell and the right textControl. drop it in
[cell addSubview:textControl];
return cell;
}
hey the reason is you are doing this things when cell is nil ? but you are not writing any code when cell is not nil.
look at this example , in this example i am adding image view in tableview cell , hence you can add textviews or any other views like this
UITableViewCell *cell = (UITableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
UIImageView *imgView;
if(cell == nil)
{
cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];
imgView = [[UIImageView alloc] initWithFrame:CGRectMake(100,0,100,62)];
[imgView setImage:[UIImage imageNamed:#"img.png"]];
imgView.tag = 55;
[cell.contentView addSubview:imgView];
[imgView release];
}
else
{
imgView = (id)[cell.contentView viewWithTag:55];
}
so as showin here imgView = (id)[cell.contentView viewWithTag:55]; you have to give tag to you and write code showing above in else..
Let you try to make the cell labels and textviews by using following code. It works for me.
if (tagvalue ==3) {
static NSString *CellIdentifier = #"Cell3";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle
reuseIdentifier:CellIdentifier] autorelease];
}
lbl7 = [[UILabel alloc] init];
[lbl7 setFont:[UIFont boldSystemFontOfSize:20]];
[cell.contentView addSubview:lbl7];
lbl7.backgroundColor = [UIColor clearColor];
lbl7.frame = CGRectMake(120, 5, 0, 40);
lbl7.tag = 70;
[lbl7 release];
lbl8 = [[UILabel alloc] init];
[lbl8 setFont:[UIFont boldSystemFontOfSize:18]];
[cell.contentView addSubview:lbl8];
lbl8.backgroundColor = [UIColor clearColor];
lbl8.textColor = [UIColor grayColor];
lbl8.frame = CGRectMake(120, 50, 0, 40);
lbl8.tag = 80;
[lbl8 release];
lbl7 = (UILabel*)[cell.contentView viewWithTag:70];
lbl8 = (UILabel*)[cell.contentView viewWithTag:80];
lbl7.text = [[rowsarray objectAtIndex:row]objectForKey:#"name"];
lbl8.text = [[rowsarray objectAtIndex:row]objectForKey:#"flavour"];
[lbl7 sizeToFit];
[lbl8 sizeToFit];
return cell;
}
if (tagvalue ==4) {
static NSString *CellIdentifier = #"Cell4";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
}
lbl9 = [[UILabel alloc] init];
[lbl9 setFont:[UIFont boldSystemFontOfSize:20]];
[cell.contentView addSubview:lbl9];
lbl9.backgroundColor = [UIColor clearColor];
lbl9.frame = CGRectMake(120, 5, 0, 40);
lbl9.tag = 90;
[lbl9 release];
lbl10 = [[UILabel alloc] init];
[lbl10 setFont:[UIFont boldSystemFontOfSize:18]];
[cell.contentView addSubview:lbl10];
lbl10.backgroundColor = [UIColor clearColor];
lbl10.textColor = [UIColor grayColor];
lbl10.frame = CGRectMake(120, 50, 0, 40);
lbl10.tag = 100;
[lbl10 release];
lbl9 = (UILabel*)[cell.contentView viewWithTag:90];
lbl10 = (UILabel*)[cell.contentView viewWithTag:100];
lbl9.text = [[rowsarray objectAtIndex:row]objectForKey:#"name"];
lbl10.text = [[rowsarray objectAtIndex:row]objectForKey:#"flavour"];
[lbl9 sizeToFit];
[lbl10 sizeToFit];
return cell;
}
I had same issue. Its not the problem with table class. The issue is at the place where you are calling this tableviewcontroller. First make the object of this call in .h and then allocate in .m, thats it..
When I was declaring in viewdidload like tbl *t = [self.storyboard...];, I was also facing the same problem. But when I put tbl *t; in .h problem solved.
I am using MGTwitterEngine and have almost EVERYTHING figured out, but for some reason I cannot figure out how to return more tweets in my timeline! It receives around 20 tweets by the method I am using and if I add a integer for example: return count = 100;, I can tell I now have 100 cells when it loads and by the scroll indicator but when I scroll to that 18- 19 cell I get this error:
SIGABRT
-[NSMutableArray objectAtIndex:]: index 20 beyond bounds [0 .. 19]'
* Call stack at first throw:
I know what it means: theres no more information to receive at cell 20. I'm baffled and went in and out of MGTwitterEngine looking for a default tweet count but I can't find it. I am using the dump to create my NSStrings and the dump only seems to give around 20 tweets per login. Please help, any suggestions are good in my book! Thank you!
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
int count = [tweets count];
// Return just enough cells to fill the screen during loading ....
if (count == 0)
count = MyCustomRowCount;
else {
//Here is where I think I need to add a else return integer but dont know how
}
return count;
return [tweets count];
return [authors count];
return [avatarsURL count];
}
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
NSString *identifier = #"cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:identifier];
if (cell == nil) {
[cell autorelease];
}
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:#"cell"]autorelease];
/*
//Here it adds a nice shadow to the table view but will crash on rotation and send a
wird dump !!!????
tableView.layer.shadowColor = [[UIColor blackColor] CGColor];
tableView.layer.shadowOffset = CGSizeMake(1.0f, 1.0f);
tableView.layer.shadowRadius = 8.0f;
tableView.layer.shadowOpacity = 1.0f;
*/
[cell.textLabel setNumberOfLines:1];
[cell.textLabel setText:[(Tweet*)[authors objectAtIndex:indexPath.row] author]];
[cell.detailTextLabel setText:[(Tweet*)[tweets objectAtIndex:indexPath.row] tweet]];
[cell.detailTextLabel setNumberOfLines:10];
[cell.textLabel setTextColor:[UIColor darkGrayColor]];
[cell.textLabel setShadowColor:[UIColor whiteColor]];
[cell.textLabel setShadowOffset:CGSizeMake(0.5, 0.5)];
[cell.detailTextLabel setTextColor:[UIColor blackColor]];
//[cell.detailTextLabel setText:[(Tweet*)[retweetCount objectAtIndex:indexPath.row]
reTweetCount]];
[cell.textLabel setUserInteractionEnabled:YES];
[cell.contentView setMultipleTouchEnabled:YES];
// cell.text = [[NSString alloc] initWithFormat:#"Cell :%i", indexPath.row];
// Here we use the new provided setImageWithURL: method to load the web image with
SDWebImageManager
[cell.imageView setImageWithURL:[NSURL URLWithString:[(Tweet*)[avatarsURL
objectAtIndex:indexPath.row]avatarURL]]
placeholderImage:[UIImage imageNamed:#"avatar.png"]];
//add gradient to cell
UIImage *gradient = [UIImage imageNamed:#"gradientcell2.png"];
UIImageView *cellimage = [[UIImageView alloc] initWithImage:gradient];
cellimage.contentMode = UIViewContentModeScaleToFill;
cell.backgroundView = cellimage;
[cellimage release];
UIImage *selectedGradient = [UIImage imageNamed:#"selectedcell.png"];
UIImageView *selectedCell = [[UIImageView alloc] initWithImage:selectedGradient];
selectedCell.contentMode = UIViewContentModeScaleToFill;
cell.selectedBackgroundView = selectedCell;
[tableView setBackgroundColor:[UIColor clearColor]];
return cell;
}
//get cell accessory
-(UITableViewCellAccessoryType)tableView:(UITableView *)tableView
accessoryTypeForRowWithIndexPath:(NSIndexPath *)indexPath {
if(indexPath.row < [tweets count]){
}
return UITableViewCellAccessoryDisclosureIndicator;
}
// custom hieght
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath*)indexPath {
return 80;
}
//select tweet bring to detail view ..... Also bring in the Users information who made the tweet!
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath*)indexPath {
//Get the selected tweets
NSString *selectedTweet = [(Tweet*)[tweets objectAtIndex:indexPath.row] tweet];
NSString *selectedUser = [(Tweet*)[tweets objectAtIndex:indexPath.row] author];
NSString *selectedUserInfo = [(Tweet*)[tweets objectAtIndex:indexPath.row] user];
NSString *retweetCount = [(Tweet*)[tweets objectAtIndex:indexPath.row] reTweetCount ];
// NSString *selectedUserFriendsCount = [(Tweet*)[tweets objectAtIndex:indexPath.row] userFriendsCount];------HUH? NO soup for ME!
NSString *selectedUserFollowersCount = [(Tweet*)[tweets objectAtIndex:indexPath.row] userFollowersCount];
//Initialize the detail view controller and display it.
TwitterDetailViewController*dvController = [[TwitterDetailViewController alloc]
initWithNibName:#"TwitterDetailViewController" bundle:[NSBundle mainBundle]];
dvController.selectedTweet = selectedTweet;
dvController.selectedUser = selectedUser;
dvController.selectedUserInfo = selectedUserInfo;
// dvController.selectedUserFriendsCount = selectedUserFriendsCount;------Doesnt reconize the call for some odd reason!
dvController.selectedUserFollowersCount = selectedUserFollowersCount;
dvController.retweetCount = retweetCount;
dvController.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
[self presentModalViewController:dvController animated:YES];
//[self.navigationController pushViewController:webController animated:YES];-------would rather use navagation controller for several obvious reasons
[dvController release];
dvController = nil;
}
UITableView doesn't it like it when you gave it something inconsistant. If you change the model, you need to call [tableView reloadData] or if you want to animate the changes call [tableView beingUpdate][tableView endUpdate] with all the insert/remove cell operations in the middle.
On another note, I'm not sure why you doing here:
NSString *identifier = #"cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:identifier];
if (cell == nil) {
[cell autorelease];
}
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle
reuseIdentifier:#"cell"];
[cell autorelease];
First if (cell == nil), calling auto release on it won't do anything.
The reuse identifier thing is a flyweight pattern. If dequeueReusableCellWithIdentifier: returns nil, it means it doesn't have a cell object in the pool for you to use and you should alloc a new one for it. dequeueReusableCellWithIdentifier also already returns an autorelease object.
Instead try this:
NSString *identifier = #"mytweetcell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:identifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:identifier] autorelease];
}
i am using the code below to implement a volume view into a cell.
[[cell detailTextLabel] setText: #""];
MPVolumeView *systemVolumeSlider = [[MPVolumeView alloc] initWithFrame: CGRectMake(100, 10, 200, 100)];
[cell addSubview: systemVolumeSlider];
[self.view addSubview:cell];
[systemVolumeSlider release];
//[MPVolumeView release];
However I have a problem with it. Whenever i scroll up or down in the tableview the MPVolumeView will be added to some other cells aswell. How could I fix this?
As mentioned in the comments, the cell with the Volume control may get re-used for non-Volume cells so it needs to be removed if it already exists. An example of how this can be done:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier] autorelease];
}
//remove the volume control (which we tagged as 10) if it already exists...
UIView *v = [cell.contentView viewWithTag:10];
[v removeFromSuperview];
cell.textLabel.text = #"some text";
if (indexPath.section == 7)
{
if (indexPath.row == 1)
{
cell.detailTextLabel.text = #"";
MPVolumeView *systemVolumeSlider = [[MPVolumeView alloc] initWithFrame:CGRectMake(100, 10, 200, 100)];
//set a tag so we can easily find it (to remove it)...
systemVolumeSlider.tag = 10;
[cell.contentView addSubview:systemVolumeSlider];
[systemVolumeSlider release];
return cell;
}
}
cell.detailTextLabel.text = #"detail";
return cell;
}
In your comments, it seems the volume control should only be on the 2nd row of the 8th section so the example is written that way. Modify as needed.
I'm not sure if this is the correct way to create a UITableViewCell in code, but it works perfectly, until I need to reload the table as its returning old cells so not loading the new content.
- (UITableViewCell *)tableView:(UITableView *)tableViewData cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableViewData dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
if (indexPath.section == 0) {
if ([marker objectForKey:#"imageUrl"]) {
UIView *transparentBackground = [[UIView alloc] initWithFrame:CGRectZero];
transparentBackground.backgroundColor = [UIColor clearColor];
cell.backgroundView = transparentBackground;
UIImageView *buildingView = [[UIImageView alloc] initWithFrame:CGRectMake(20, 10, 100, 100)];
buildingView.image = [self imageWithImage:[ImageManipulator makeRoundCornerImage:[self loadImage:[NSURL URLWithString:[NSString stringWithFormat:#"http://www.qut.edu.au%#", [marker objectForKey:#"imageUrl"]]]] :9 :9]];
[cell addSubview:buildingView];
} else {
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(10, 10, 200, 15)];
label.text = #"test";
[cell addSubview:label];
[label release];
}
} else {
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(10, 10, 200, 15)];
label.text = #"test";
[cell addSubview:label];
[label release];
}
}
return cell;
}
Basically the cell that gets returned on line 3 is not nil (its the old one), therefore the if statement isn't fired and it returns the old cell. I could load a new cell each time but that will have issues with load and memory usage.
Whats the correct way to do this?
It will be the old one as it's only (hopefully) created once, that's the point of queueing and dequeueing the reusable cell, to save memory. You'll have to just clear out any of the properties you need to.