Memory warrning tableviewcell - ios

Question

I have two tableviewcell in xib file and I use both of them.
When I use one of them the memory is still 7.3MB, but when I use both memory grow very fast.
Please help me. I don't now what is wrong.
My code is below:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
NSUInteger row = [indexPath row];
NSDictionary *rowData = [self.events objectAtIndex:row];
static NSString *CellIdentifierL = #"LeftCell";
static NSString *CellIdentifierR = #"RightCell";
SampleTableCell *cellLeft = [tableView dequeueReusableCellWithIdentifier:CellIdentifierL];
SampleTableCell *cellRight = [tableView dequeueReusableCellWithIdentifier:CellIdentifierR];
if (cellLeft == nil) {
NSArray* topLevelObjects = [[NSBundle mainBundle] loadNibNamed:#"LeftTableCell" owner:self options:nil];
for (id currentObject in topLevelObjects) {
if ([currentObject isKindOfClass:[SampleTableCell class]]) {
cellLeft = (SampleTableCell *)currentObject;
break;
}
}
}
if (cellRight == nil) {
NSArray* topLevelObjects = [[NSBundle mainBundle] loadNibNamed:#"RightTableCell" owner:self options:nil];
for (id currentObject in topLevelObjects) {
if ([currentObject isKindOfClass:[SampleTableCell class]]) {
cellRight = (SampleTableCell *)currentObject;
break;
}
}
}
return (row%2==0)?cellRight:cellLeft;
}

Answer 1

You need to create only the cell you need. Your code should be like this:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
NSUInteger row = [indexPath row];
NSDictionary *rowData = [self.events objectAtIndex:row];
static NSString *CellIdentifierL = #"LeftCell";
static NSString *CellIdentifierR = #"RightCell";
if (cellLeft == nil) {
SampleTableCell *cellLeft = [tableView dequeueReusableCellWithIdentifier:CellIdentifierL];
NSArray* topLevelObjects = [[NSBundle mainBundle] loadNibNamed:#"LeftTableCell" owner:self options:nil];
for (id currentObject in topLevelObjects) {
if ([currentObject isKindOfClass:[SampleTableCell class]]) {
cellLeft = (SampleTableCell *)currentObject;
break;
}
}
return cellLeft;
}
if (cellRight == nil) {
SampleTableCell *cellRight = [tableView dequeueReusableCellWithIdentifier:CellIdentifierR];
NSArray* topLevelObjects = [[NSBundle mainBundle] loadNibNamed:#"RightTableCell" owner:self options:nil];
for (id currentObject in topLevelObjects) {
if ([currentObject isKindOfClass:[SampleTableCell class]]) {
cellRight = (SampleTableCell *)currentObject;
break;
}
}
return cellRight;
}
return nil;
}

Answer 2

I change to this:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
NSUInteger row = [indexPath row];
NSDictionary *rowData = [self.events objectAtIndex:row];
SampleTableCell *cell;
if(row%2==0){
cell = [[[NSBundle mainBundle] loadNibNamed:#"RightTableCell" owner:self options:nil]objectAtIndex:0];
}else{
cell = [[[NSBundle mainBundle] loadNibNamed:#"LeftTableCell" owner:self options:nil]objectAtIndex:0];
}
cell.labelName.text = [rowData objectForKey:#"name"];
return cell;
}
But I don't know that is good idea?

Answer 3

This is not a good way to do this. You are creating both cells for every row, but you only use one of them. You should also use the newer way to use a xib based cell -- that is, use registerNib:forCellWithReuseIdentifier: in viewDidLoad, to register both nibs. Do your check for odd/even rows first, and dequeue the correct cell (no need to check for nil when using the register method). You do it like this:
- (void)viewDidLoad {
[super viewDidLoad];
[self.tableView registerNib:[UINib nibWithNibName:#"SampleCell1" bundle:nil] forCellReuseIdentifier:#"SampleCell1"];
[self.tableView registerNib:[UINib nibWithNibName:#"SampleCell2" bundle:nil] forCellReuseIdentifier:#"SampleCell2"];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.row % 2 == 0) {
SampleCell *cell = [tableView dequeueReusableCellWithIdentifier:#"SampleCell1" forIndexPath:indexPath];
// populate cell with data
return cell;
}else{
SampleCell *cell = [tableView dequeueReusableCellWithIdentifier:#"SampleCell2" forIndexPath:indexPath];
// populate cell with data
return cell;
}
}
This is all you need to do. There's no need to check for a nil cell, because dequeueReusableCellWithIdentifier:forIndexPath: is guaranteed to return a valid cell if you either register a nib, or make the cell in a storyboard (in which case you don't need to register anything).