Creating a UITableView Programmatically

问题:

I have an application in Xcode 4.6 which uses storyboards. I added a UITableView to a view controller class, which worked as expected. However, when I tried deleting the UITableView in the storyboard and adding it back into the same class programmatically, I ran into two specific problems:

1) Although I set the UITableViewCell type to be of type subtitle, the detail label no longer appears.

2) The segue that should occur when I select a cell does not occur, and prepare segue is not even being called, indicating that no message is being sent to the table view when a cell is selected.

Here is the relevant code:

@interface StatsTableViewController () <UITableViewDataSource, UITableViewDelegate>
@property (strong, nonatomic) UITableView *tableView;

@end

@implementation StatsTableViewController

-(UITableView *)makeTableView
{
    CGFloat x = 0;
    CGFloat y = 50;
    CGFloat width = self.view.frame.size.width;
    CGFloat height = self.view.frame.size.height - 50;
    CGRect tableFrame = CGRectMake(x, y, width, height);

    UITableView *tableView = [[UITableView alloc]initWithFrame:tableFrame style:UITableViewStylePlain];

    tableView.rowHeight = 45;
    tableView.sectionFooterHeight = 22;
    tableView.sectionHeaderHeight = 22;
    tableView.scrollEnabled = YES;
    tableView.showsVerticalScrollIndicator = YES;
    tableView.userInteractionEnabled = YES;
    tableView.bounces = YES;

    tableView.delegate = self;
    tableView.dataSource = self;

    return tableView;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.tableView = [self makeTableView];
    [self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:@"newFriendCell"];
    [self.view addSubview:self.tableView];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"newFriendCell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];

    if (cell == nil) 
    {
        cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
    }

    Friend *friend = [self.fetchedResultsController objectAtIndexPath:indexPath];

     **//THIS DATA APPEARS**
    cell.textLabel.text = friend.name;
    cell.textLabel.font = [cell.textLabel.font fontWithSize:20];
    cell.imageView.image = [UIImage imageNamed:@"icon57x57"];

    **//THIS DATA DOES NOT APPEAR**
    cell.detailTextLabel.text = [NSString stringWithFormat:@"%i Games", friend.gameCount];
    cell.detailTextLabel.textColor = [UIColor lightGrayColor];

    return cell;
}

 -(void)tableView:(UITableView *)tableView didDeselectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [self performSegueWithIdentifier:@"detailsView" sender:self];
}

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
      //I set the segue identifier in the interface builder
     if ([segue.identifier isEqualToString:@"detailsView"])
     {

         NSLog(@"segue"); //check to see if method is called, it is NOT called upon cell touch

         NSIndexPath *indexPath = [self.tableView indexPathForCell:sender];
         ///more code to prepare next view controller....
     }
}

I am not sure what I am forgetting to do so that I can solve these two issues. Any help is appreciated.

回答1:

When you register a class, and use dequeueReusableCellWithIdentifier:forIndexPath:, the dequeue method is guaranteed to return a cell, so your if (cell == nil) clause is never entered. So, just do it the old way, don't register the class, and use dequeueReusableCellWithIdentifier:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"newFriendCell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil) {
        cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
    }
//etc.
return cell;
}

As for the segue, it can't be called because you can't make a segue to a table that you've created in code, not in IB. Again, go back to the old way and use tableView:didSelectRowAtIndexPath: which will be called when you select a cell. Instantiate your detail controller there and do the trasition in code.

After edit:

I didn't see your added code there. You've implemented didDeselectRowAtIndexPath rather than didSelectRowAtIndexPath. If you change that, your segue should work.

回答2:

You might be do that its works 100% .

- (void)viewDidLoad
{
    [super viewDidLoad];
    // init table view
    tableView = [[UITableView alloc] initWithFrame:self.view.bounds style:UITableViewStylePlain];

    // must set delegate & dataSource, otherwise the the table will be empty and not responsive
    tableView.delegate = self;
    tableView.dataSource = self;

    tableView.backgroundColor = [UIColor cyanColor];

    // add to canvas
    [self.view addSubview:tableView];
}

#pragma mark - UITableViewDataSource
// number of section(s), now I assume there is only 1 section
- (NSInteger)numberOfSectionsInTableView:(UITableView *)theTableView
{
    return 1;
}

// number of row in the section, I assume there is only 1 row
- (NSInteger)tableView:(UITableView *)theTableView numberOfRowsInSection:(NSInteger)section
{
    return 1;
}

// the cell will be returned to the tableView
- (UITableViewCell *)tableView:(UITableView *)theTableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *cellIdentifier = @"HistoryCell";

    // Similar to UITableViewCell, but 
    JSCustomCell *cell = (JSCustomCell *)[theTableView dequeueReusableCellWithIdentifier:cellIdentifier];
    if (cell == nil) {
        cell = [[JSCustomCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
    }
    // Just want to test, so I hardcode the data
    cell.descriptionLabel.text = @"Testing";

    return cell;
}

#pragma mark - UITableViewDelegate
// when user tap the row, what action you want to perform
- (void)tableView:(UITableView *)theTableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSLog(@"selected %d row", indexPath.row);
}

@end

回答3:

- (void)viewDidLoad {
     [super viewDidLoad];
     arr=[[NSArray alloc]initWithObjects:@"ABC",@"XYZ", nil];
     tableview = [[UITableView alloc]initWithFrame:tableFrame style:UITableViewStylePlain];   
     tableview.delegate = self;
     tableview.dataSource = self;
     [self.view addSubview:tableview];
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return arr.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"MyCell"];

    if(cell == nil)
    {
        cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"MyCell"];
    }

    cell.textLabel.text=[arr objectAtIndex:indexPath.row];

    return cell;
}

回答4:

- (void)viewDidLoad
{
    [super viewDidLoad];
    tableView = [[UITableView alloc] initWithFrame:self.view.bounds style:UITableViewStylePlain];
    tableView.delegate = self;
    tableView.dataSource = self;

    tableView.backgroundColor = [UIColor grayColor];

    // add to superview
    [self.view addSubview:tableView];
}

#pragma mark - UITableViewDataSource
- (NSInteger)numberOfSectionsInTableView:(UITableView *)theTableView
{
    return 1;
}

- (NSInteger)tableView:(UITableView *)theTableView numberOfRowsInSection:    (NSInteger)section
{
    return 1;
}

// the cell will be returned to the tableView
- (UITableViewCell *)tableView:(UITableView *)theTableView  cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *cellIdentifier = @"HistoryCell";

    // Similar to UITableViewCell, but 
    UITableViewCell *cell = (UITableViewCell *)[theTableView dequeueReusableCellWithIdentifier:cellIdentifier];
    if (cell == nil)
    {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
    }
    cell.descriptionLabel.text = @"Testing";
    return cell;
}

回答5:

sample table

 #import "StartreserveViewController.h"
 #import "CollectionViewController.h"
 #import "TableViewCell1.h"
@interface StartreserveViewController ()


{
NSArray *name;
NSArray *images;
NSInteger selectindex;

}

@end

@implementation StartreserveViewController

- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.

self.view.backgroundColor = [UIColor blueColor];
_startReservetable.backgroundColor = [UIColor blueColor];


name = [[NSArray alloc]initWithObjects:@"Mobiles",@"Costumes",@"Shoes", 
nil];
images = [[NSArray 
 alloc]initWithObjects:@"mobilestitle.jpg",@"costumetitle.jpeg", 
 @"shoestitle.png",nil];



  }

 - (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

pragma mark - UiTableview Datasource

 -(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
 {
return 1;
 }

 -(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:
 (NSInteger)section
 {
return 3;
 }

 - (UITableViewCell *)tableView:(UITableView *)tableView 
  cellForRowAtIndexPath:(NSIndexPath *)indexPath
 {


static NSString *cellId = @"tableview";

TableViewCell1  *cell =[tableView dequeueReusableCellWithIdentifier:cellId];


cell.cellTxt .text = [name objectAtIndex:indexPath.row];

cell.cellImg.image = [UIImage imageNamed:[images 
objectAtIndex:indexPath.row]];

return cell;



 }


-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:
(NSIndexPath *)indexPath
 {
selectindex = indexPath.row;
[self performSegueWithIdentifier:@"second" sender:self];
}



   #pragma mark - Navigation

 // In a storyboard-based application, you will often want to do a little     
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {

if ([segue.identifier isEqualToString:@"second"])

  {
    CollectionViewController *obj = segue.destinationViewController;
           obj.receivename = [name objectAtIndex:selectindex];

  }



// Get the new view controller using [segue destinationViewController].
// Pass the selected object to the new view controller.
}

 @end

.h

#import <UIKit/UIKit.h>

@interface StartreserveViewController :      
UIViewController<UITableViewDelegate,UITableViewDataSource>    
@property (strong, nonatomic) IBOutlet UITableView *startReservetable;

 @end

回答6:

vc.m

#import "ViewController.h"

import "secondViewController.h"

 @interface ViewController ()
 {

NSArray *cityArray;
NSArray *citySubTitleArray;
NSArray *cityImage;
NSInteger selectindexpath;

}
@end

 @implementation ViewController

 - (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.

cityArray = [[NSArray 
alloc]initWithObjects:@"Coimbatore",@"Salem",@"Chennai",nil];

citySubTitleArray = [[NSArray alloc]initWithObjects:@"1",@"2",@"3", nil];
cityImage = [[NSArray alloc]initWithObjects:@"12-300x272.png"
 , @"380267_70d232fc33b44d4ebe7b42bbe63ee9be.png",@"apple-logo_318
 -40184.png", nil];

 }


 #pragma mark - UITableView Data Source

 - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
 {
return 1;

 }

 - (NSInteger) tableView:(UITableView *)tableView numberOfRowsInSection 
 :(NSInteger)section
  {
return cityImage.count;
 }

- (UITableViewCell *)tableView:(UITableView *)tableView 
cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *cellId = @"city";

UITableViewCell *cell =
 [tableView dequeueReusableCellWithIdentifier:cellId];

if (cell == nil)
{
    cell = [[UITableViewCell 
  alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:cellId];
}

cell.textLabel.text = [cityArray objectAtIndex:indexPath.row];
cell.detailTextLabel.text = [citySubTitleArray objectAtIndex:indexPath.row];
cell.imageView.image = [UIImage imageNamed:
 [cityImage objectAtIndex:indexPath.row]];




 //    NSData *data = [[NSData alloc]initWithContentsOfURL:
 [NSURL URLWithString:@""]];

 //    cell.imageView.image = [UIImage imageWithData:data];

return cell;
}

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath
:  (NSIndexPath *)indexPath
 {
 NSLog(@"---- %@",[cityArray objectAtIndex:indexPath.row]);
 NSLog(@"----- %@",[cityImage objectAtIndex:indexPath.row]);
 selectindexpath=indexPath.row;
 [self performSegueWithIdentifier:@"second" sender:self];
  }

  #pragma mark - Navigation

 // In a storyboard-based application, you will often want to do a little p
 - (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
    {
 // Get the new view controller using [segue destinationViewController].
 // Pass the selected object to the new view controller.
 if ([segue.identifier isEqualToString:@"second"])
 {
    secondViewController *object=segue.destinationViewController;
    object.cityName=[cityArray objectAtIndex:selectindexpath];
    object.cityImage=[cityImage objectAtIndex:selectindexpath];
       }
 }


- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
 }

 @end

vc.m

 #import <UIKit/UIKit.h>

 @interface ViewController : UIViewController<UITableViewDataSource
  , UITableViewDelegate>
 @property (strong, nonatomic) IBOutlet UITableView *cityLabelList;

@end

sv.m

 #import <UIKit/UIKit.h>

@interface secondViewController : UIViewController
@property(strong, nonatomic) NSString *cityName;
 @property(strong,nonatomic)NSString *cityImage;
@end

sv.h

#import "secondViewController.h"

 @interface secondViewController ()

 @property (strong, nonatomic) IBOutlet UILabel *lbl_desc;
 @property (strong, nonatomic) IBOutlet UIImageView *img_city;
    @end

 @implementation secondViewController

 - (void)viewDidLoad {
 [super viewDidLoad];
// Do any additional setup after loading the view.
self.title=self.cityName;


if ([self.cityName isEqualToString:@"Coimbatore"])
{


    self.lbl_desc.text=@"Coimbatore city";
    self.img_city.image=[UIImage imageNamed:
    [NSString stringWithFormat:@"%@",self.cityImage]];
}
 else if ([self.cityName isEqualToString:@"Chennai"])
 {

    self.lbl_desc.text= @"Chennai City Gangstar";
    self.img_city.image=[UIImage imageNamed:
   [NSString stringWithFormat:@"%@",self.cityImage]];

   }
  else
   {


    self.lbl_desc.text= @"selam City";
    self.img_city.image=[UIImage imageNamed:
   [NSString stringWithFormat:@"%@",self.cityImage]];

   }
 }

- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

回答7:

Creating a tableview using tableViewController .

import UIKit

class TableViewController: UITableViewController
{
    let tableViewModel = TableViewModel()
    var product: [String] = []
    var price: [String] = []
    override func viewDidLoad()
    {
        super.viewDidLoad()
        self.tableView.contentInset = UIEdgeInsetsMake( 20, 20 , 0, 0)
        let priceProductDetails = tableViewModel.dataProvider()

        for (key, value) in priceProductDetails
        {
            product.append(key)
            price.append(value)
        }
    }

    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int
    {
        return product.count
    }

    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
    {
        let cell = UITableViewCell(style: .Value1, reuseIdentifier: "UITableViewCell")
        cell.textLabel?.text = product[indexPath.row]
        cell.detailTextLabel?.text = price[indexPath.row]
        return cell
    }

    override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath)
    {
        print("You tapped cell number \(indexPath.row).")
    }
}

回答8:

- (NSInteger)tableView:(UITableView *)theTableView numberOfRowsInSection:(NSInteger)section
{
    return 1;
}

- (UITableViewCell *)tableView:(UITableView *)theTableView  cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *cellIdentifier = @"HistoryCell";

    UITableViewCell *cell = (UITableViewCell *)[theTableView dequeueReusableCellWithIdentifier:cellIdentifier];
    if (cell == nil)
    {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
    }
    cell.descriptionLabel.text = @"Testing";
    return cell;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    //Code for selection.
}

these are UITableView delegate methods.

回答9:

#import "ViewController.h"

@interface ViewController ()

{

    NSMutableArray *name;

}

@end


- (void)viewDidLoad 

{

    [super viewDidLoad];
    name=[[NSMutableArray alloc]init];
    [name addObject:@"ronak"];
    [name addObject:@"vibha"];
    [name addObject:@"shivani"];
    [name addObject:@"nidhi"];
    [name addObject:@"firdosh"];
    [name addObject:@"himani"];

    _tableview_outlet.delegate = self;
    _tableview_outlet.dataSource = self;

}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

{

return [name count];

}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

{

    static NSString *simpleTableIdentifier = @"cell";

    UITableViewCell *cell = [tableView       dequeueReusableCellWithIdentifier:simpleTableIdentifier];

    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];
    }

    cell.textLabel.text = [name objectAtIndex:indexPath.row];
    return cell;
}