What is UITableViewCell identifier's role when I create UITableView programmatically? - ios

Question

Previously when I create a UITableView using storyboard, I set the cell identifier in property inspector and paste it into method cellForRowAtIndexPath, then use method dequeueReusableCellWithIdentifier to create a new UITableViewCell. However, when I create a UITableView programmatically, I have nowhere to set up cell identifier. I mean, I can arbitrarily appoint an identifier without having to match that in the property inspector. Am I right? And how should I create a UITableViewCell under this situation?

Answer 1

You can create UITableview and UITableviewCell both programmatically as below.
Create Tableview Programmatically,
#interface ViewController () <UITableViewDataSource>{
//create tableview instance
UITableView *tableViewPro;
}
Alloc it in viewDidLoad
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
// init table view
tableViewPro = [[UITableView alloc] initWithFrame:self.view.bounds style:UITableViewStylePlain];
// must set delegate & dataSource, otherwise the the table will be empty and not responsive
tableViewPro.dataSource = self;
tableViewPro.backgroundColor = [UIColor cyanColor];
// add to canvas
[self.view addSubview:tableViewPro];
}
Assign number of rows and UITableview cell in Tableview datasource methods
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
return 10;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *cellIdentifier = #"Tableviewcell";
// Similar to UITableViewCell, but
TableViewCell *cell = (TableViewCell *)[tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell == nil) {
//initialize uitableviewcell programmatically.
cell = [[TableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
}
// Just want to test, so I hardcode the data
cell.descriptionLabel.text = [NSString stringWithFormat:#"Testing index %ld",(long)indexPath.row];
return cell;
}
Now, create your UITableviewCell programmatically. First Add New->file->Cocoa Touch class->Enter tableviewcellname with subclass-of UITableviewCell and UNCHECK the 'Also create XIB file', because cell will be created programmatically.
Two files will be created .h and .m of UITableviewCell, I've create UITableviewCell with TableViewCell name. below is the code to achieve it programmatically.
#interface TableViewCell : UITableViewCell
#property (nonatomic,retain) UILabel *descriptionLabel;
#end
Synthesize descriptionLabel in #implementation file of TableViewCell
#synthesize descriptionLabel = _descriptionLabel;
Below is the initialization function function of creating a UITableviewCell Programmatically. ADD THIS FUNCTION ON #implementation file of TableViewCell
- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
//it will create UITableiviewCell programmatically and assign that instance on self.
self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
if (self) {
// configure control(s)
self.descriptionLabel = [[UILabel alloc] initWithFrame:CGRectMake(5, 10, 300, 30)];
self.descriptionLabel.textColor = [UIColor blackColor];
self.descriptionLabel.font = [UIFont fontWithName:#"Arial" size:12.0f];
[self addSubview:self.descriptionLabel];
}
return self;
}
Below is the resulted output.