indexpath.row显示的行数更少

Question

I have created an tableview with an array. There are 7 items in my array. But in cellForRowAtIndexPath method i'm unable to get indexpath.row == 6 . What could be the reason. Code is below for this.

  -(void)viewDidLoad
    {
      [super viewDidLoad];

      self.menu = [NSArray arrayWithObjects:@"Home",@"ansCategory",@"askQue",@"myQue",@"likedQue", @"topQue", @"topUser",nil];             
    }

    -(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
     {
       // Return the number of sections.
       return 1;
     }

      -(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
     {
        // Return the number of rows in the section.
        // NSLog(@"count::::::%d",self.menu.count);
           return self.menu.count;
     }
       -(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
    {
        NSString *cellIdentifier = @"Cell";    
        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];

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

        NSLog(@"rows:%@",indexPath);
        NSLog(@"row:%@",[self.menu objectAtIndex:indexPath.row]);
    }
    return cell;

 }

I'm getting following out put:

[here] ( https://www.dropbox.com/s/pz6t34xr7l4glxz/menu1.png )

first index is overlaying on last one.

Answer 1

The cell is reused. Put your log statement outside of the if(cell=nil) :

Here is the working example for outputting the contents of the array in a tableview. Item with index 6 which is the seventh in the array ("topUser") is in red.

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

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];

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

    NSLog(@"rows:%@",indexPath);
    NSLog(@"row:%@",[self.menu objectAtIndex:indexPath.row]);

    cell.textLabel.text = self.menu[indexPath.row];

    if (indexPath.row == 6)
        cell.textLabel.textColor = [UIColor redColor];        
    return cell;
}

Answer 2

For N items the last indexpath is (N-1)

Thus, if you have 10 items, then the index path of last item is 9 because the indexpath of 1st item in array is 0.

indexPath of items starts with 0 and not 1.

Try to access the index path in your answer like below in your code

Instead of :

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

        NSLog(@"rows:%@",indexPath);
        NSLog(@"row:%@",[self.menu objectAtIndex:indexPath.row]);
    }

Write

    if (cell == nil) {
            cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle                   reuseIdentifier:cellIdentifier];
 }
    //Access the indexPath outside here... 
    //Because once the cells are created and not nil 
    //then the above scope will be bypassed.
    NSLog(@"rows:%@",indexPath);
    NSLog(@"row:%@",[self.menu objectAtIndex:indexPath.row]);

Answer 3

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

每当需要创建新行并将其添加到tableview时都会执行.tableview会填充行，以便需要在屏幕上支付时通过调用完全相同的方法来创建它，因此如果第7行不可见在屏幕上，该方法不会针对第7行执行，即indexpath.row 6，因此要获取记录第7行的方法，只需向下滚动即可使表格可见该单元格，它将执行该方法，您可以有日志

Answer 4

我将代码更改为以下代码，它可以正常工作。

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:nil];