Question

我使用uitableview来显示json解析数据。解析后的数据存储在数组中，数组列表为100，符合uitableview。但它在objectAtIndex崩溃在 {forloop} ，它将崩溃报告显示为

由于未捕获的异常'NSInvalidArgumentException'而终止应用程序，原因：' - [NSMutableArray insertObject：atIndex：]：尝试将nil对象插入0' *

请帮助我

   - (void)viewDidLoad
{
    self.responseData = [NSMutableData data];
    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:openexchangeURl]];
    [[NSURLConnection alloc] initWithRequest:request delegate:self];
    [super viewDidLoad];

}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response 
{
    [responseData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data 
{
    [responseData appendData:data];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
    [connection release];
    self.responseData = nil;
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection 
{
    [connection release];

    NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
    self.responseData = nil;

    values = [responseString JSONValue];
    array = [[NSMutableArray alloc] init];
    NSMutableArray *arrTitle = [[NSMutableArray alloc] init];
    NSMutableArray *arrValues = [[NSMutableArray alloc] init];
    array =[values valueForKey:@"rates"];

    NSLog(@"array values:--> %@",array);
//    NSLog(@"values:--> %@",values);
//    NSLog(@"Particular values:--> %@",[[values valueForKey:@"rates"] valueForKey:@"AED"]);

    tempDict1 = (NSMutableDictionary *)array;            
    NSArray *arr;// =[[NSArray alloc]init];
    arr = [[tempDict1 valueForKey:@"rates"] componentsSeparatedByString:@";"];
    NSLog(@"arr-->%@",arr);
    NSString *subStar = @"=";
    [arrTitle removeAllObjects];
    [arrValues removeAllObjects];

    for (int i=0; i<[arr count]-1; i++)
    {
        [arrTitle addObject:[[arr objectAtIndex:i] substringToIndex:NSMaxRange([[arr objectAtIndex:i] rangeOfString:subStar])-1]];
        [arrValues addObject:[[arr objectAtIndex:i] substringFromIndex:NSMaxRange([[arr objectAtIndex:i] rangeOfString:subStar])]];
        NSLog(@"arrTitle is:--> %@",arrTitle);
    }

    tempDict1 = (NSMutableDictionary*)[array objectAtIndex:0];
    array = [values valueForKey:@"rates"];
    NSLog(@"tempDict--%@",[tempDict1 objectForKey:@"AED"]);

    [array retain];
    [tbl_withData reloadData];

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

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    NSLog(@"array-->%@",array);
    return [array count];

}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    intIndexPath = indexPath.row;
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil)
    {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
        cell.textLabel.adjustsFontSizeToFitWidth = YES; 
        cell.textLabel.font = [UIFont systemFontOfSize:8]; 
        cell.textLabel.numberOfLines = 4; 

    }

//    NSLog(@"data is like:--> %@",array);
//    cell.textLabel.text= [NSString stringWithFormat:@"%@",[array objectAtIndex:intIndexPath]];
    cell.textLabel.text =[array objectAtIndex:intIndexPath];

    return cell;
}

Answer 1

数组中只有一个项目，这里只添加一个对象：

array = [[NSMutableArray alloc] init];
[array addObject:[values valueForKey:@"rates"]];

您应该将从[values valueForKey:@"rates"]获得的值分配给数组变量。还要使数组变量成为保留值的属性。

@property (nonatomic, strong) NSArray *array;

然后将其分配给属性：

self.array  = [values valueForKey:@"rates"];

同时将单元格的所有样式移动到创建新单元格的位置。这样可以加快速度，因为每次都不会改变单元格的样式。

- (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] autorelease];
       cell.textLabel.adjustsFontSizeToFitWidth = YES;  
       cell.textLabel.font = [UIFont systemFontOfSize:8];  
       cell.textLabel.numberOfLines = 4;  

    }
    NSLog(@"data is like:--> %@",array);
    //    NSString *cellValue =[array objectAtIndex:indexPath.row];
    //    cell.textLabel.text = cellValue;

    cell.textLabel.text= [NSString stringWithFormat:@"%@",[array objectAtIndex:indexPath.row]];

    return cell;
}

Answer 2

以正确的格式从服务器获取数据...在您的情况下，您的数据在一个数组中。所以让它在不同的阵列中..

{"reply":["AED = 3.673188","AFN = 48.5725","","","",""]}

或者您可以解析您的响应并将单个数据保存到另一个数组中......

（由于未捕获的异常'NSInvalidArgumentException而终止应用程序）

2 个答案: