Question

我正在尝试过滤调用JSON文件的Table View数据并将数据解析到Table View。我收到了一些奇怪的错误。这是我的代码：

#import "FacebookViewController.h"
#import "RNBlurModalView.h"
#import "FacebookPost.h"
#import "TwitterPost.h"

#define CELL_CONTENT_WIDTH 320.0f
#define CELL_CONTENT_MARGIN 10.0f
#define FONT_SIZE 14.0f

@interface FacebookViewController ()
{
    NSInteger refreshIndex;
    NSArray *fbPost;
    NSArray *pic;
}

@end

@implementation FacebookViewController
@synthesize tweets;

- (void)refreshChannels:(id)sender {

    if (tweets.count == 0) return;

    // disable UI
    self.title = @"Updating...";
    self.navigationController.view.userInteractionEnabled = YES;
    refreshIndex = 0;
}

- (void) reloadFB {

}
- (void)viewDidLoad
{
    [super viewDidLoad];


    UIBarButtonItem *button = [[UIBarButtonItem alloc]
                               initWithBarButtonSystemItem:UIBarButtonSystemItemRefresh
                               target:self
                               action:@selector(refreshChannels:)];
    self.navigationItem.rightBarButtonItem = button;

    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Menu" style:UIBarButtonItemStyleBordered target:self action:@selector(showMenu)];

    UIPanGestureRecognizer *gestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(swipeHandler:)];
    [self.view addGestureRecognizer:gestureRecognizer];

    self.myTableView.separatorColor = [UIColor clearColor];

     [self issueLoadRequest];
}

- (void)swipeHandler:(UIPanGestureRecognizer *)sender
{
    [[self sideMenu] showFromPanGesture:sender];
}

#pragma mark -
#pragma mark Button actions

- (void)showMenu
{
    [[self sideMenu] show];
}

#pragma mark - Table view data source

- (void)issueLoadRequest
{
    if (changeData.selectedSegmentIndex == 1) {
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        NSData* data = [NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://my-site-facebookparse.php?person=Person"]];
        [self performSelectorOnMainThread:@selector(receiveData:) withObject:data waitUntilDone:YES];
    });
    } else {
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
            NSData* data = [NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://my-site-twitterparse.php?person=Person"]];
            [self performSelectorOnMainThread:@selector(receiveData:) withObject:data waitUntilDone:YES];
        });
    }
}

- (void)receiveData:(NSData *)data {
    if (changeData.selectedSegmentIndex == 1) {
    self.tweets = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];
    [self.myTableView reloadData];
    } else {
        self.tweets1 = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];
        [self.myTableView reloadData];
    }
}

- (void)receiveTwitter:(NSData *)data {
    // When we have the data, we serialize it into native cocoa objects. (The outermost element from twitter is
    // going to be an array. I JUST KNOW THIS. Reload the tableview once we have the data.
    self.tweets1 = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];
    [self.myTableView reloadData];
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    if (changeData.selectedSegmentIndex == 1) {
        return self.tweets.count;
    } else {
        return self.tweets1.count;
    }
}

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

    // The element in the array is going to be a dictionary. I JUST KNOW THIS. The key for the tweet is "text".
    NSDictionary *tweet = [self.tweets objectAtIndex:indexPath.row];
    NSDictionary *tweet1 = [self.tweets1 objectAtIndex:indexPath.row];

    FacebookPost *cell = (FacebookPost *)[tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
    if (cell == nil)
    {
        NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"FacebookPost" owner:self options:nil];
        cell = [nib objectAtIndex:0];
    }

    if (changeData.selectedSegmentIndex == 1) {
        cell.fbPost.text = [tweet objectForKey:@"message"];
    } else {
        cell.fbPost.text = [tweet1 objectForKey:@"tweet"];
    }
    return cell;
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return 90;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (changeData.selectedSegmentIndex == 1) {
    //Open the link
    int storyIndex = [indexPath indexAtPosition: [indexPath length] - 1];
    NSString * storyLink = [[tweets objectAtIndex: storyIndex] objectForKey:@"message"];
    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:storyLink]];

    RNBlurModalView *modal = [[RNBlurModalView alloc] initWithViewController:self title:@"Message" message:storyLink];
    [modal show];

    NSString *formattedJSON = [[NSString alloc] initWithData:[NSJSONSerialization dataWithJSONObject:[self.tweets objectAtIndex:indexPath.row] options:NSJSONWritingPrettyPrinted error:nil] encoding:NSUTF8StringEncoding];
    NSLog(@"tweet:\n%@", formattedJSON);
    } else {
        //Öppna länken eller liknande
        int storyIndex = [indexPath indexAtPosition: [indexPath length] - 1];
        NSString * storyLink = [[tweets objectAtIndex: storyIndex] objectForKey:@"tweet"];
        [[UIApplication sharedApplication] openURL:[NSURL URLWithString:storyLink]];

        RNBlurModalView *modal = [[RNBlurModalView alloc] initWithViewController:self title:@"Message" message:storyLink];
        [modal show];

        // Spit out some pretty JSON for the tweet that was tapped. Neato.
        NSString *formattedJSON = [[NSString alloc] initWithData:[NSJSONSerialization dataWithJSONObject:[self.tweets objectAtIndex:indexPath.row] options:NSJSONWritingPrettyPrinted error:nil] encoding:NSUTF8StringEncoding];
        NSLog(@"tweet:\n%@", formattedJSON);
    }
}



@end

即使我已将其设置为下载Facebook帖子，表格视图数据也会在发布时下载Twitter帖子。这很奇怪......请帮我解决这个问题！

Answer 1

您需要做几件事。首先，您需要设置选定的段索引。在[self issueLoadRequest]中致电viewDidLoad之前，您应该像这样设置所选索引：

changeData.selectedSegmentIndex = 0;

这会将第一个段设置为选定的段。此外，更改选定的段时，您需要确保加载了正确的数据。为此，您应将以下内容添加到viewDidLoad：

[changeData addTarget:self action:@selector(segmentedControlSelectedIndexChanged:) forControlEvents:UIControlEventValueChanged];

和合作方法segmentedControlSelectedIndexChanged：

- (void)segmentedControlSelectedIndexChanged:(id)sender 
{ 
    [self issueLoadRequest]; 
}

现在，只要您在Facebook细分和Twitter细分之间切换，它就会调用相应的API，下载数据并更新表格视图。根据连接的速度，在选择段和表视图更新之间可能会有一个小但明显的延迟。

UISegmentControl过滤器表查看数据JSON错误

1 个答案: