Updating A Specific Row In UITableView Without Reloading The Whole Table - ios

Question

I would like to update the the text of a label in tableview without reloaddata.
I try ((uilabel *)[self.tableview viewWtihTag:10]).text = Newstring
but its not work.
Is it correct? or have another solution?

Answer 1

Using this method - (void)reloadRowsAtIndexPaths:(NSArray<NSIndexPath *> *)indexPaths withRowAnimation:(UITableViewRowAnimation)animation is correct. However, you should keep track of the value to be loaded in every row in each cell, and then access them every time a row is reloaded when the user scrolls the table.
Here is a sample:
#interface ViewController ()<UITableViewDelegate, UITableViewDataSource>
#property NSMutableArray *labelValueListForSection0;
#property NSMutableArray *labelValueListForSection1;
#property NSMutableArray *labelValueListForSection2;
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
_labelValueListForSection2 = [[NSMutableArray alloc] initWithObjects:#"value1", #"value2", #"value3", nil];
}
- (void)changeAnItem
{
[_labelValueListForSection2 setObject:#"ChangedValue" atIndexedSubscript:1];
[_table reloadRowsAtIndexPaths:#[[NSIndexPath indexPathForRow:1 inSection:2]] withRowAnimation:UITableViewRowAnimationNone];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *identifier = #"SimpleTableItem";
UITableViewCell *tableCell = [tableView dequeueReusableCellWithIdentifier:identifier];
if(tableCell == nil)
{
tableCell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identifier];
}
switch(indexPath.section)
{
case 0:
tableCell.textLabel.text = #"Test";
break;
case 1:
tableCell.textLabel.text = #"Test";
break;
case 2:
tableCell.textLabel.text = [_labelValueListForSection2 objectAtIndex:indexPath.row];
break;
case 3:
tableCell.textLabel.text = #"Test";
break;
case 4:
tableCell.textLabel.text = #"Test";
break;
default:
break;
}
return tableCell;
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 5;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 3;
}
#end
As you can see, I am keeping track of the value of each row and I am storing them inside an array. In my case, I have an array of values for each row for a specific section. So that when this method
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath;
is called, it will fetch the value that should be assigned to that row.
In case you don't know, iOS is reusing each table cell for better performance and better memory management. So, if you encounter cases such as why is a value of one of my rows is duplicated in other rows, it is because that instance of tableCell is reused in other rows.
So, in order to make sure that each time a cell is loaded, and the value should be correct. You have to keep track of the value for each row and reassign it to that cell each time it is reloaded.
Hope this will help you solve your problem.

Answer 2

Try to reload particular cell of table ...
NSIndexPath* rowToReload = [NSIndexPath indexPathForRow:3 inSection:0];
[myUITableView reloadRowsAtIndexPaths:[NSArray arrayWithObjects:rowToReload, nil] withRowAnimation:UITableViewRowAnimationNone];
And add code to change text in cellForRowAtIndexPath:

Answer 3

- (void)reloadRowsAtIndexPaths:(NSArray *)indexPaths withRowAnimation:(UITableViewRowAnimation)animation;
Use this method. This helps you to solve your problem