Question

我正在尝试使用两个单独的部分创建UITableviewController，其中一个部分包含UIImage个，另一部分包含UIButton个部分。这是代码。第一部分工作正常，但是如果我将返回2设置为部分的数量，则应用程序崩溃并出现错误：

'NSRangeException', reason: '*** -[__NSArrayI objectAtIndex:]: index 1 beyond bounds [0 .. 0]'
*** First throw call stack:

这是代码：

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return 2;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
if (section==0)
{
    return [arrayOfMessages count];
}
else{
    return 1;
}
}

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

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

if (indexPath.section==0)

if (cell == nil) {
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    cell.selectionStyle = UITableViewCellSelectionStyleNone;
    tableView.separatorStyle = UITableViewCellSeparatorStyleNone;

    balloonView = [[UIImageView alloc] initWithFrame:CGRectZero];
    balloonView.tag = 1;

    label = [[UILabel alloc] init];
    label.backgroundColor = [UIColor clearColor];
    label.textColor = [UIColor whiteColor];
    label.tag = 2;
    label.numberOfLines = 0;
    label.lineBreakMode = UILineBreakModeWordWrap;
    label.font = [UIFont fontWithName:@"Chalkduster" size:14];

    UIView *message = [[UIView alloc] initWithFrame:CGRectMake(0.0, 0.0, cell.frame.size.width, cell.frame.size.height)];
    message.tag = 0;
    [message addSubview:balloonView];
    [message addSubview:label];

    message.autoresizingMask = UIViewAutoresizingFlexibleWidth;

    [cell.contentView addSubview:message];


    cell.backgroundColor = [UIColor clearColor];
    cell.backgroundView = [UIView new];
    cell.selectedBackgroundView = [UIView new];

}
else
{
    balloonView = (UIImageView *)[[cell.contentView viewWithTag:0] viewWithTag:1];
    label = (UILabel *)[[cell.contentView viewWithTag:0] viewWithTag:2];
}

NSString *textAll = [arrayOfMessages objectAtIndex:indexPath.row];
NSString *textMessage = [textAll substringFromIndex:2];
NSString *textType = [textAll substringToIndex:2];

CGSize size = [textMessage sizeWithFont:[UIFont fontWithName:@"Chalkduster" size:14] constrainedToSize:CGSizeMake(240.0f, 480.0f) lineBreakMode:UILineBreakModeWordWrap];

if ([textType isEqualToString:@"ME"]) {
    balloonView.frame = CGRectMake(318.0f - (size.width + 28.0f), 2.0f, size.width + 28.0f, size.height + 15.0f);
    balloonView.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin;
    balloon = [[UIImage imageNamed:@"GreenMessage.png"] stretchableImageWithLeftCapWidth:24 topCapHeight:15];
    label.frame = CGRectMake(307.0f - (size.width + 5.0f), 8.0f, size.width + 5.0f, size.height);
    label.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin;

    label.textColor = [UIColor whiteColor];

} else if ([textType isEqualToString:@"HE"]) {

    balloonView.frame = CGRectMake(2.0, 2.0, size.width + 28, size.height + 15);
    balloonView.autoresizingMask = UIViewAutoresizingFlexibleRightMargin;
    balloon = [[UIImage imageNamed:@"GrayMessage.png"] stretchableImageWithLeftCapWidth:24 topCapHeight:15];
    label.frame = CGRectMake(16, 8, size.width + 5, size.height);
    label.autoresizingMask = UIViewAutoresizingFlexibleRightMargin;

    label.textColor = [UIColor blackColor];
}

balloonView.layer.cornerRadius = 5;
balloonView.clipsToBounds = YES;
balloonView.image = balloon;
label.text = textMessage;

}

return cell;
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {

NSString *body = [arrayOfMessages objectAtIndex:indexPath.row];
CGSize size = [body sizeWithFont:[UIFont fontWithName:@"Chalkduster" size:14] constrainedToSize:CGSizeMake(240.0, 480.0) lineBreakMode:UILineBreakModeWordWrap];
return size.height + 20;
}

我该怎么做？

Answer 1

错误与各部分无关。你做的是对的。可能导致崩溃的是NSArray arrayOfMessages 。

在第1部分（第二部分）中，根据您的代码，行数为1：

if (section==0)
{
    return [arrayOfMessages count];
}
else
{
    return 1;
}

但是如果NSArray arrayOfMessages 中没有数据怎么办？

NSString *textAll = [arrayOfMessages objectAtIndex:indexPath.row];

代码将在这里破解。

Answer 2

问题是当tableview开始创建第2节remove if（indexPath.section == 0）时，你没有创建tableviewcell的实例。除此之外，如果你有基于部分的tableview，你需要存储2维数组。第一个数组用于每个部分的部分和项目。对于insance

self.arrayOfMessages = @[ @[ @"Section_Text1" , @"Section1_Text2" ], @[ @"Section2_Text1" , @"Section2_Text2" , @"Section2_Text3" ] ];

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
 return self.arrayOfMessages[indexPath.section].count;
}

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


    NSString *text = self.arrayOfMessages[indexPath.section][indexPath.row];

///TODO
}

Answer 3

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

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:
 cellIdentifier];

    if (cell == nil) 
    {
        cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
        // Your's code here 
    }

    NSString *textAll = nil;

    if (indexPath.section == 0) 
    {
        // fetch array object here
        textAll = [arrayOfMessages objectAtIndex:indexPath.row];

    }
    else if (indexPath.section == 1)
    {
       // Since your array for section 1 returns only one array's object
       // you should fetch it appropriately by specifying the index of the array

       textAll = [arrayOfMessages objectAtIndex:"Specify the index of the array you want to fetch here which should be within the the bound of arrayOfMessages"];
    }

    // configure your cell here

    return cell;
}

UITableViewController有两个部分

3 个答案: