Ios 当我返回时，TableView显示相同数据两次或更多次？

当我从第二个tableViewController返回到第一个，从第一个viewController返回到第二个tableViewController时，xml文件数据重新加载到tableView上。当tableViewController中的数据首次出现时，它会显示两次相同的xml文件数据。为什么？我在我的项目中使用本地xml文件

//在第一视图控件中

- (void)viewDidLoad {
    [super viewDidLoad];
        self.eastIndiaArr = [[NSMutableArray alloc]init];
        self.westInadiaArr = [[NSMutableArray alloc]init];
        self.southIndiaArr = [[NSMutableArray alloc]init];
        self.northIndiaArr = [[NSMutableArray alloc]init];
}
- (IBAction)onTapParseData:(UIButton *)sender {

    NSString *xmlFilePath = [[NSBundle mainBundle] pathForResource:@"india" ofType:@"xml"];

    self.xmlParser = [[NSXMLParser alloc]initWithContentsOfURL:[NSURL fileURLWithPath:xmlFilePath]];

    self.xmlParser.delegate = self;

    BOOL success = [self.xmlParser parse];

    if (success) {
        NSLog(@"Parse success");
    } else {
        NSLog(@"Parse not success");
    }

    StatesTableViewController *stvc = [self.storyboard instantiateViewControllerWithIdentifier:@"STVC"];

    stvc.eastIndiaArr1 = self.eastIndiaArr;
    stvc.westIndiaArr1 = self.westInadiaArr;
    stvc.northIndiaArr1 = self.northIndiaArr;
    stvc.southIndiaArr1 = self.southIndiaArr;

    [self.navigationController pushViewController:stvc animated:YES];
}

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string {

    NSString *trimmedString = [string stringByTrimmingCharactersInSet:
                           [NSCharacterSet whitespaceAndNewlineCharacterSet]];

    if (trimmedString.length > 0) {

        if ([self.zoneNodeElement isEqualToString:@"eastIndia"]) {
            [self.eastIndiaArr addObject:string];
        } else if ([self.zoneNodeElement isEqualToString:@"westIndia"]) {
            [self.westInadiaArr addObject:string];
        } else if ([self.zoneNodeElement isEqualToString:@"northIndia"]) {
            [self.northIndiaArr addObject:string];
        } else if ([self.zoneNodeElement isEqualToString:@"southIndia"]) {
            [self.southIndiaArr addObject:string];
        }

    }
}

-(void)viewWillAppear:(BOOL)animated {

    [self.tableView reloadData];
}

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

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"ID" forIndexPath:indexPath];

    if (indexPath.section == 0) {
        cell.textLabel.text = [self.eastIndiaArr1 objectAtIndex:indexPath.row];
    } else if (indexPath.section == 1) {
        cell.textLabel.text = [self.westIndiaArr1 objectAtIndex:indexPath.row];
    } else if (indexPath.section == 2) {
        cell.textLabel.text = [self.northIndiaArr1 objectAtIndex:indexPath.row];
    } else if (indexPath.section == 3) {
        cell.textLabel.text = [self.southIndiaArr1 objectAtIndex:indexPath.row];
    }

    return cell;
}

//在tableViewControl中

- (void)viewDidLoad {
    [super viewDidLoad];
        self.eastIndiaArr = [[NSMutableArray alloc]init];
        self.westInadiaArr = [[NSMutableArray alloc]init];
        self.southIndiaArr = [[NSMutableArray alloc]init];
        self.northIndiaArr = [[NSMutableArray alloc]init];
}
- (IBAction)onTapParseData:(UIButton *)sender {

    NSString *xmlFilePath = [[NSBundle mainBundle] pathForResource:@"india" ofType:@"xml"];

    self.xmlParser = [[NSXMLParser alloc]initWithContentsOfURL:[NSURL fileURLWithPath:xmlFilePath]];

    self.xmlParser.delegate = self;

    BOOL success = [self.xmlParser parse];

    if (success) {
        NSLog(@"Parse success");
    } else {
        NSLog(@"Parse not success");
    }

    StatesTableViewController *stvc = [self.storyboard instantiateViewControllerWithIdentifier:@"STVC"];

    stvc.eastIndiaArr1 = self.eastIndiaArr;
    stvc.westIndiaArr1 = self.westInadiaArr;
    stvc.northIndiaArr1 = self.northIndiaArr;
    stvc.southIndiaArr1 = self.southIndiaArr;

    [self.navigationController pushViewController:stvc animated:YES];
}

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string {

    NSString *trimmedString = [string stringByTrimmingCharactersInSet:
                           [NSCharacterSet whitespaceAndNewlineCharacterSet]];

    if (trimmedString.length > 0) {

        if ([self.zoneNodeElement isEqualToString:@"eastIndia"]) {
            [self.eastIndiaArr addObject:string];
        } else if ([self.zoneNodeElement isEqualToString:@"westIndia"]) {
            [self.westInadiaArr addObject:string];
        } else if ([self.zoneNodeElement isEqualToString:@"northIndia"]) {
            [self.northIndiaArr addObject:string];
        } else if ([self.zoneNodeElement isEqualToString:@"southIndia"]) {
            [self.southIndiaArr addObject:string];
        }

    }
}

-(void)viewWillAppear:(BOOL)animated {

    [self.tableView reloadData];
}

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

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"ID" forIndexPath:indexPath];

    if (indexPath.section == 0) {
        cell.textLabel.text = [self.eastIndiaArr1 objectAtIndex:indexPath.row];
    } else if (indexPath.section == 1) {
        cell.textLabel.text = [self.westIndiaArr1 objectAtIndex:indexPath.row];
    } else if (indexPath.section == 2) {
        cell.textLabel.text = [self.northIndiaArr1 objectAtIndex:indexPath.row];
    } else if (indexPath.section == 3) {
        cell.textLabel.text = [self.southIndiaArr1 objectAtIndex:indexPath.row];
    }

    return cell;
}

---

这是因为每次在同一个旧数组中添加新对象时，请尝试删除数组中的旧对象。（在代码中需要的任何位置）

---

这是因为每次在同一个旧数组中添加新对象时，请尝试删除数组中的旧对象。（在代码中需要的任何位置）

喜欢

- (IBAction)onTapParseData:(UIButton *)sender { 
// before call the request remove the previous value in your array
[self.eastIndiaArr removeAllObjects]; 
[self.westInadiaArr removeAllObjects]; 
[self.northIndiaArr removeAllObjects]; 
[self.southIndiaArr removeAllObjects];
NSString *xmlFilePath = [[NSBundle mainBundle] pathForResource:@"india" ofType:@"xml"]; 

self.xmlParser = [[NSXMLParser alloc]initWithContentsOfURL:[NSURL fileURLWithPath:xmlFilePath]]; 

self.xmlParser.delegate = self; 

[self.xmlParser parse];
}

喜欢

- (IBAction)onTapParseData:(UIButton *)sender { 
// before call the request remove the previous value in your array
[self.eastIndiaArr removeAllObjects]; 
[self.westInadiaArr removeAllObjects]; 
[self.northIndiaArr removeAllObjects]; 
[self.southIndiaArr removeAllObjects];
NSString *xmlFilePath = [[NSBundle mainBundle] pathForResource:@"india" ofType:@"xml"]; 

self.xmlParser = [[NSXMLParser alloc]initWithContentsOfURL:[NSURL fileURLWithPath:xmlFilePath]]; 

self.xmlParser.delegate = self; 

[self.xmlParser parse];
}

---

没有这个

[self.tableView重载数据]

try onceAlready我尝试了这个，但它第二次也显示相同的数据…您期望的输出是什么我想在我再次返回时只在tableView中打印一次数据…好的，在您的页面中，您调用这个

NSString*xmlFilePath=[[NSBundle mainbndle]pathForResource:@“india”of type:@“xml”]不包含此
[self.tableView重载数据]
try onceAlready我尝试了这个，但它第二次也显示相同的数据…您期望的输出是什么我想在我再次返回时只在tableView中打印一次数据…好的，在您的页面中，您调用这个
NSString*xmlFilePath=[[NSBundle mainbndle]pathForResource:@“india”of type:@“xml”]
再次尝试重新加载表视图。@PratikShah-它是委托i
foundCharacters
的每次调用，因此在webservice调用之前删除其中的数据，它不是JSON，而是XMLtry再次加载表视图。@PratikShah-它是委托i
foundCharacters
的每次调用，所以在webservice调用之前删除数据，它不是JSON，而是XML