在 iOS 中获取 JSON 数据并填充 TableView

Question

晚上好！

我需要一些帮助。我从 Google Places API 获取了一些 JSON 格式的数据，但我无法在 iPad（基于 SplitView 的应用程序）中填充 TableView。我是从iOS开发开始的，所以可能有很多错误！我使用了一个项目示例，该示例使用 Twitter API 来检索帖子，只是重命名了 JSON 数据名称。

我在项目中使用了四个文件并实现了该功能：

SimpleSplitController.h
SimpleSplitController.m
SplitSampleAppDelegate.h
SplitSampleAppDelegate.m

我在 SplitSampleDelegate.m 文件中收到错误，因为它在那里进行了检查...

如果有人可以帮助我，我将非常感激！

下面是实现的代码：

SplitSampleAppDelegate.h

#import <UIKit/UIKit.h>

@class APTabBarControllerForSplitController;

@interface SplitSampleAppDelegate : NSObject <UIApplicationDelegate, UITabBarControllerDelegate> {

    NSMutableData *responseData;
    NSMutableArray *tweets;

}

@property (nonatomic, retain) IBOutlet UIWindow *window;

@property (nonatomic, retain) IBOutlet APTabBarControllerForSplitController *tabBarController;

@property (nonatomic, retain) NSMutableArray *tweets;

@end

SplitSampleAppDelegate.m

#import "SplitSampleAppDelegate.h"
#import "APTabBarControllerForSplitController.h"

@implementation SplitSampleAppDelegate

@synthesize window=_window;

@synthesize tabBarController=_tabBarController;

@synthesize tweets;

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    self.tabBarController.delegate = self;

    // Override point for customization after application launch.
    // Add the tab bar controller's current view as a subview of the window
    // Add the view controller's view to the window and display.
    responseData = [[NSMutableData data] retain];
    tweets = [NSMutableArray array];
    NSURLRequest *request = [NSURLRequest requestWithURL:
                             [NSURL URLWithString:@"https://maps.googleapis.com/maps/api/place/search/json?location=-15.815347,-47.9164097&radius=500&types=restaurant&sensor=true&key=AIzaSyBLY-lBALViJ6ybrgtOqQGhsCDQtsdKsnc"]];
    [[NSURLConnection alloc] initWithRequest:request delegate:self];



    self.window.rootViewController = self.tabBarController;
    [self.window makeKeyAndVisible];
    return YES;
}

#pragma mark NSURLConnection delegate methods
- (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 {
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
    [connection release];
    NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
    [responseData release];

    NSDictionary *results = [responseString JSONValue];

    NSMutableArray *allTweets = [results objectForKey:@"results"];

    //This is the part that I get an ERROR
    [viewController setTweets:allTweets];
    [window addSubview:viewController.view];
    [window makeKeyAndVisible];
}

SimpleSplitController.h

#import <UIKit/UIKit.h>
#import "APSplitViewController.h"
#import <MapKit/MapKit.h>

@interface SimpleSplitController : APSplitViewController {
    NSMutableData *responseData;
    NSArray *tweets;
}

@property (nonatomic, retain) UIViewController *left;
@property (nonatomic, retain) UIViewController *right;
@property (nonatomic, retain) NSArray *tweets;

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context;

@end

SimpleSplitController.m

#import "SimpleSplitController.h"
#import <QuartzCore/QuartzCore.h>
#import "JSON/JSON.h"
#import "Tweet.h"

@interface SimpleSplitController()
- (UIColor *) randomColor;
- (UIViewController*) randomViewController1;
- (UIViewController*) randomViewController2;
- (UIViewController*) randomViewController3;
- (void) buttonPushRandomViewController1;
- (void) buttonPushRandomViewController2;

@end

@implementation SimpleSplitController

@synthesize left, right;

@synthesize tweets;

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

    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
    }

    // Configure the cell...

    NSDictionary *aTweet = [tweets objectAtIndex:[indexPath row]];

    cell.textLabel.text = [aTweet objectForKey:@"name"];
    cell.textLabel.adjustsFontSizeToFitWidth = YES;
    cell.textLabel.font = [UIFont systemFontOfSize:12];
    cell.textLabel.minimumFontSize = 10;
    cell.textLabel.numberOfLines = 4;
    cell.textLabel.lineBreakMode = UILineBreakModeWordWrap;

    cell.detailTextLabel.text = [aTweet objectForKey:@"vicinity"];

    NSURL *url = [NSURL URLWithString:[aTweet objectForKey:@"icon"]];
    NSData *data = [NSData dataWithContentsOfURL:url];
    cell.imageView.image = [UIImage imageWithData:data];
    cell.selectionStyle = UITableViewCellSelectionStyleNone;
    return cell;

}

Answer 1

很可能你在这里错了。您正在检查对象，而不是值。

 NSMutableArray *allTweets = [results valueForKey:@"results"];

乔普你的问题已经解决了。