Question

我有2个屏幕，在第一个单击按钮时它应该转到第二个屏幕从服务器获取数据并在第二个屏幕的表格视图中显示。但是使用以下代码我无法在表格视图中显示数据

#import "FirstTableViewController.h"

@interface FirstTableViewController ()<NSXMLParserDelegate>
@property(nonatomic,strong)NSXMLParser*xmlparse;
@property(nonatomic,strong)NSMutableString*tempstr;
@property(nonatomic,strong)NSMutableArray*arr;

@end

@implementation FirstTableViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    NSMutableURLRequest*req=[[NSMutableURLRequest alloc]init];
    NSURL*url=[NSURL URLWithString:@"http://www.thomas-bayer.com/sqlrest/CUSTOMER/"];
    [req  setURL:url];
    [[[NSURLSession sharedSession]dataTaskWithRequest:req completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
        // SMXMLDocument *document = [SMXMLDocument documentWithData:data error:&error];

        NSString*str=[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
        _xmlparse=[[NSXMLParser alloc]initWithData:data];
        _xmlparse.delegate=self;
        [_xmlparse parse];
    }] resume];
    [_table reloadData];
}

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{
    _tempstr=[[NSMutableString alloc]initWithString:string];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(nullable NSString *)namespaceURI qualifiedName:(nullable NSString *)qName attributes:(NSDictionary<NSString *, NSString *> *)attributeDict;{
    if([elementName isEqualToString:@"CUSTOMER"]){
        self.tempstr=[[NSMutableString alloc]init];

    }
    if([elementName isEqualToString:@"CUSTOMERList"]){
        self.arr=[[NSMutableArray alloc]init];

    }

}
- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(nullable NSString *)namespaceURI qualifiedName:(nullable NSString *)qName;{

    if([elementName isEqualToString:@"CUSTOMER"]){
       [_arr addObject:self.tempstr];
        self.tempstr=nil;
    }
   // NSLog(@"arr is %@",self.arr);
}
#pragma mark - Table view data source

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return self.arr.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cel" forIndexPath:indexPath];

    cell.textLabel.text=[self.arr objectAtIndex:indexPath.row];
    return cell;
}

@end

Answer 1

做两件事

<强>第一

- (void)viewDidLoad {
[super viewDidLoad];

arr = [NSMutableArray array]; // initilize the memory of array 

NSMutableURLRequest*req=[[NSMutableURLRequest alloc]init];
NSURL*url=[NSURL URLWithString:@"http://www.thomas-bayer.com/sqlrest/CUSTOMER/"];
[req  setURL:url];
[[[NSURLSession sharedSession]dataTaskWithRequest:req completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
    // SMXMLDocument *document = [SMXMLDocument documentWithData:data error:&error];

    NSString*str=[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
    _xmlparse=[[NSXMLParser alloc]initWithData:data];
    _xmlparse.delegate=self;
    [_xmlparse parse];
}] resume];

}

<强>第二

 - (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(nullable NSString *)namespaceURI qualifiedName:(nullable NSString *)qName;{

if([elementName isEqualToString:@"CUSTOMER"]){
   [_arr addObject:self.tempstr];
    self.tempstr=@"";
}

 if(arr.count >0)
 {
   dispatch_async(dispatch_get_main_queue(), ^{
             [_table reloadData];
        });

  }

 }

来自服务器的数据未显示在tableview中

1 个答案: