在 tableview 中显示来自 web 服务的解析值

Question

我在tableViewcontroller 类的viewDidLoad 方法中调用一个webservice，并在另一个类中解析数据如下

- (void)viewDidLoad {
    [super viewDidLoad];

    dataWebService = [[NSMutableData data] retain];
    NSString *authString = [[[NSString stringWithFormat:@"%@:%@",@"admin", @"admin"] dataUsingEncoding:NSUTF8StringEncoding] base64Encoding];        


    NSMutableURLRequest *request = [[NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://172.16.3.47:8980/opennms/rest/alarms?limit=5"]] retain];
    [request setValue:[NSString stringWithFormat:@"Basic %@",authString] forHTTPHeaderField:@"Authorization"];


    [[NSURLConnection alloc] initWithRequest:request delegate:self];


    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
    // self.navigationItem.rightBarButtonItem = self.editButtonItem;
}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
    [dataWebService setLength:0];
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    [dataWebService appendData:data];
}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
     NSLog(@"Eror during connection: %@", [error description]);
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
    [connection release];

    NSString* responseString = [[NSString alloc] initWithData:dataWebService encoding:NSUTF8StringEncoding];

    AlarmWSParse* alarmParser = [[AlarmWSParse alloc]init];

    severity = [alarmParser xmlParser:responseString];

    NSLog(@"no of elements in array %d",[severity count]);

    NSLog(@"Back to Alarm List View controller and severtiy array is %@",severity);
}

然后将表格单元格中的这个严重性数组值设置为

- (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.
    return [severity count];
}

// Customize the appearance of table view cells.
- (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];
    }

    // Configure the cell...
    NSString* cellValue = [severity objectAtIndex:indexPath.row];
    NSLog(@"cellvalue %@",cellValue);
    cell.textLabel.text = cellValue;

    return cell;
}

表格仍然为空，但NSLog 正确显示所有数据。

此外，在调用和解析 Web 服务后，我的应用程序在模拟器中崩溃，而调试器中没有任何错误消息。

如何将数组中的这些值显示到 tableview？

猜猜看……我在tabelView:cellForRowAtIndexPath 中包含的 cellValue 或任何其他 nslog 消息的 nslog 消息不会在控制台中打印出来……

这是我的控制台视图

[Session started at 2011-12-22 11:12:07 +0530.]
2011-12-22 11:12:09.358 WebServiceTab[11815:207] do while loopalarm
2011-12-22 11:12:09.359 WebServiceTab[11815:207] severity is MAJOR
2011-12-22 11:12:09.359 WebServiceTab[11815:207] do while loopalarm
2011-12-22 11:12:09.359 WebServiceTab[11815:207] severity is MAJOR
2011-12-22 11:12:09.360 WebServiceTab[11815:207] do while loopalarm
2011-12-22 11:12:09.360 WebServiceTab[11815:207] severity is MAJOR
2011-12-22 11:12:09.360 WebServiceTab[11815:207] do while loopalarm
2011-12-22 11:12:09.360 WebServiceTab[11815:207] severity is MINOR
2011-12-22 11:12:09.361 WebServiceTab[11815:207] do while loopalarm
2011-12-22 11:12:09.361 WebServiceTab[11815:207] severity is MAJOR
2011-12-22 11:12:09.361 WebServiceTab[11815:207] no of elements in array 5
2011-12-22 11:12:09.362 WebServiceTab[11815:207] Back to Alarm List View controller and severtiy array is (
    MAJOR,
    MAJOR,
    MAJOR,
    MINOR,
    MAJOR
)

我在这里分享一些源代码文件：https://gist.github.com/fce50a3c4d20cb9c4677 如果您能找到任何错误，请查看。我的应用似乎只崩溃了:(

Answer 1

在完成connectionDidFinishLoading 的解析后尝试[tableView reloadData]。

Answer 2

检查 [severity objectAtIndex:indexPath.row] 是否返回 NSString ，我认为应该是别的东西

 NSString* cellValue = [severity objectAtIndex:indexPath.row];

以及尝试 the.evangelist 提到的 [tableView reloadData]

Answer 3

我多次遇到这个问题，我通过这种方法解决了。

1) 使用临时数组保存解析数据
2) 分配您的表数组
3) 临时数组数据添加到您的数组中，用于表数组
4）重新加载你的表

Answer 4

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[dataWebService appendData:data];
[self.tableview reloadData];
}

试试这个可能会奏效....

编辑：

由于您的崩溃，我认为您没有retain 您的NSMutableArray 严重性。尝试后在 viewDidLoad 中......

[[severity alloc] init];
[severity retain];

Answer 5

我认为在您的代码表重新加载问题。请在收到 webservice 的响应后重新加载表格。