区段数未确认时如何管理UITableView

Question

我使用的是UITableView，它根据数据动态创建多个部分。从1到12。分区名称是月份的名称。如何将w.r.t检查为节名称。我的代码是

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [sectionArray count];
}

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
return [sectionArray objectAtIndex:section];
}

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

int count = 0;
for(int counter=0; counter<[sectionArray count]; counter++)
{
    NSString *month = [sectionArray objectAtIndex:counter];
    if([month isEqualToString:@"October"])
    {
        count = [octoberArray count];
    }
    else if([month isEqualToString:@"November"])
    {
        count = [novemberArray count];
    }
    else if([month isEqualToString:@"December"])
    {
        count = [decemberArray count];
    }
    else if([month isEqualToString:@"January"])
    {
        count = [januaryArray count];
    }
    else if([month isEqualToString:@"February"])
    {
        count = [febuaryArray count];
    }
    else if([month isEqualToString:@"March"])
    {
        count = [marchArray count];
    }
    else if([month isEqualToString:@"April"])
    {
        count = [aprilArray count];
    }
    else if([month isEqualToString:@"May"])
    {
        count = [mayArray count];
    }
    else if([month isEqualToString:@"June"])
    {
        count = [juneArray count];
    }
    else if([month isEqualToString:@"July"])
    {
        count = [julyArray count];
    }
    else if([month isEqualToString:@"August"])
    {
        count = [augustArray count];
    }
    else
    {
        count = [septemberArray count];
    }
}

return count;

}

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

HistoryCell *cell = (HistoryCell *)[tableView dequeueReusableCellWithIdentifier:@"historyCell"];
if(cell == nil)
{
    cell = [[[NSBundle mainBundle]loadNibNamed:@"HistoryCell" owner:self options:nil] objectAtIndex:0];
}

for(int counter=0; counter<[sectionArray count]; counter++)
{
    NSString *month = [sectionArray objectAtIndex:counter];
    if([month isEqualToString:@"October"])
    {
        cell.glassesLabel.text = [NSString stringWithFormat:@"%@ Glasses",[octoberGlassesArray objectAtIndex:indexPath.row]];
        cell.unitLabel.text    = @"Unit";
        cell.dateLabel.text    = [octoberArray objectAtIndex:indexPath.row];
    }
    else if([month isEqualToString:@"November"])
    {
        cell.glassesLabel.text = [NSString stringWithFormat:@"%@ Glasses",[novemberGlassesArray objectAtIndex:indexPath.row]];
        cell.dateLabel.text    = [novemberArray objectAtIndex:indexPath.row];
    }
    else if([month isEqualToString:@"December"])
    {
        cell.glassesLabel.text = [NSString stringWithFormat:@"%@ Glasses",[decemberGlassesArray objectAtIndex:indexPath.row]];
        cell.dateLabel.text    = [decemberArray objectAtIndex:indexPath.row];
    }
    else if([month isEqualToString:@"January"])
    {
        cell.glassesLabel.text = [NSString stringWithFormat:@"%@ Glasses",[januaryGlassesArray objectAtIndex:indexPath.row]];
        cell.dateLabel.text    = [januaryArray objectAtIndex:indexPath.row];
    }
    else if([month isEqualToString:@"February"])
    {
        cell.glassesLabel.text = [NSString stringWithFormat:@"%@ Glasses",[febuaryGlassesArray objectAtIndex:indexPath.row]];
        cell.dateLabel.text    = [febuaryArray objectAtIndex:indexPath.row];
    }
    else if([month isEqualToString:@"March"])
    {
        cell.glassesLabel.text = [NSString stringWithFormat:@"%@ Glasses",[marchGlassesArray objectAtIndex:indexPath.row]];
        cell.dateLabel.text    = [marchArray objectAtIndex:indexPath.row];
    }
    else if([month isEqualToString:@"April"])
    {
        cell.glassesLabel.text = [NSString stringWithFormat:@"%@ Glasses",[aprilGlassesArray objectAtIndex:indexPath.row]];
        cell.dateLabel.text    = [aprilArray objectAtIndex:indexPath.row];
    }
    else if([month isEqualToString:@"May"])
    {
        cell.glassesLabel.text = [NSString stringWithFormat:@"%@ Glasses",[mayGlassesArray objectAtIndex:indexPath.row]];
        cell.dateLabel.text    = [mayArray objectAtIndex:indexPath.row];
    }
    else if([month isEqualToString:@"June"])
    {
        cell.glassesLabel.text = [NSString stringWithFormat:@"%@ Glasses",[juneGlassesArray objectAtIndex:indexPath.row]];
        cell.dateLabel.text    = [juneArray objectAtIndex:indexPath.row];
    }
    else if([month isEqualToString:@"July"])
    {
        cell.glassesLabel.text = [NSString stringWithFormat:@"%@ Glasses",[julyGlassesArray objectAtIndex:indexPath.row]];
        cell.dateLabel.text    = [julyArray objectAtIndex:indexPath.row];
    }
    else if([month isEqualToString:@"August"])
    {
        cell.glassesLabel.text = [NSString stringWithFormat:@"%@ Glasses",[augustGlassesArray objectAtIndex:indexPath.row]];
        cell.dateLabel.text    = [augustArray objectAtIndex:indexPath.row];
    }
    else
    {
        cell.glassesLabel.text = [NSString stringWithFormat:@"%@ Glasses",[septemberGlassesArray objectAtIndex:indexPath.row]];
        cell.dateLabel.text    = [septemberArray objectAtIndex:indexPath.row];
    }
}

return cell;
}

应用程序崩溃。如何解决此问题？

Answer 1

我相信您并不清楚UITableViewDataSource是如何工作的。但是如果我正确理解了你的想法，下面的代码应该可以解决这个问题：

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return [sectionArray count];
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    NSArray *yourMonthArray = //Here get an array for adequate month
    return [yourMonthArray count];
}

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
    NSArray *arr = @[@"January",@"February",...,@"December"];
    // asserts are optional. Just for sure you initialized your data well.
    NSAssert(arr.count == 12, @"The number of months is not valid");
    NSAssert(arr.count == [sectionArray count], @"Number of months is different than number of sections");
    return arr[section];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    HistoryCell *cell = (HistoryCell *)[tableView dequeueReusableCellWithIdentifier:@"historyCell"];
    if(cell == nil)
    {
        // Please consider using UINib instread.
        cell = [[[NSBundle mainBundle]loadNibNamed:@"HistoryCell" owner:self options:nil] objectAtIndex:0];
    }
    NSString *month = [sectionArray objectAtIndex:indexpath.section];
    cell.glassesLabel.text = [NSString stringWithFormat:@"%@ Glasses",[octoberGlassesArray objectAtIndex:indexPath.section]];
    cell.unitLabel.text    = @"Unit";
    NSArray *yourMonthArray = //Here get an array for adequate month
    cell.dateLabel.text    = yourMonthArray[indexPath.row];
    return cell;
}