iOS 8 Objective-C搜索栏和表格视图使用Google自动完成功能

Question

我是iOS开发的新手，现在已经被这个问题困扰了两个星期。 我正在尝试从Google搜索结果中创建具有自动完成功能的搜索栏。 我最能做到这一点的方法是按照Hybrid Forge的本教程进行 。 （我发现其他教程没有使用ARC，并且已经过时了。）

我可以看到URL连接可以通过NSLog正常工作，但是问题出在我重新分配我的proposalArray时。 如果我注释掉这部分：

_suggestionArray = [NSArray arrayWithArray:json[@"responseData"][@"results"]];
[_tableView reloadData];

它给出了这个错误：

[__NSCFDictionary isEqualToString:]: unrecognized selector sent to instance 0x7f968be3a060
2015-05-21 17:43:11.277 AutoComplete[865:65704] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFDictionary isEqualToString:]: unrecognized selector sent to instance 0x7f968be3a060'
*** First throw call stack:
(
    0   CoreFoundation                      0x00000001077daa75 __exceptionPreprocess + 165
    1   libobjc.A.dylib                     0x0000000107473bb7 objc_exception_throw + 45
    2   CoreFoundation                      0x00000001077e1d1d -[NSObject(NSObject) doesNotRecognizeSelector:] + 205
    3   CoreFoundation                      0x00000001077399dc ___forwarding___ + 988
    4   CoreFoundation                      0x0000000107739578 _CF_forwarding_prep_0 + 120
    5   UIKit                               0x0000000107f4cdbd -[UITableViewLabel setText:] + 81
    6   AutoComplete                        0x0000000106f40acd -[ViewController tableView:cellForRowAtIndexPath:] + 333
    7   UIKit                               0x0000000107cc1e03 -[UITableView _createPreparedCellForGlobalRow:withIndexPath:willDisplay:] + 508
    8   UIKit                               0x0000000107ca1901 -[UITableView _updateVisibleCellsNow:isRecursive:] + 2846
    9   UIKit                               0x0000000107cb778c -[UITableView layoutSubviews] + 213
    10  UIKit                               0x0000000107c441c3 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 521
    11  QuartzCore                          0x000000010b4d6c58 -[CALayer layoutSublayers] + 150
    12  QuartzCore                          0x000000010b4cb87e _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 380
    13  QuartzCore                          0x000000010b4cb6ee _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 24
    14  QuartzCore                          0x000000010b43936e _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 242
    15  QuartzCore                          0x000000010b43a482 _ZN2CA11Transaction6commitEv + 390
    16  QuartzCore                          0x000000010b43aaed _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 89
    17  CoreFoundation                      0x000000010770f507 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23
    18  CoreFoundation                      0x000000010770f460 __CFRunLoopDoObservers + 368
    19  CoreFoundation                      0x0000000107705293 __CFRunLoopRun + 1123
    20  CoreFoundation                      0x0000000107704bc6 CFRunLoopRunSpecific + 470
    21  GraphicsServices                    0x000000010adcaa58 GSEventRunModal + 161
    22  UIKit                               0x0000000107bca580 UIApplicationMain + 1282
    23  AutoComplete                        0x0000000106f41663 main + 115
    24  libdyld.dylib                       0x0000000109d88145 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)

这是我的以下代码：[ViewController.h]

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController
@property (weak, nonatomic) IBOutlet UITableView *tableView;
@property (weak, nonatomic) IBOutlet UISearchBar *searchBar;
@property (strong, readwrite, nonatomic) NSArray *suggestionArray;

@end

[ViewController.m]

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

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

#pragma mark - UITableViewDataSource Methods

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

- (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];
    }

    cell.textLabel.text = [_suggestionArray objectAtIndex:indexPath.row];

    return cell;
}

#pragma mark - UITableViewDelegate Methods

- (void)tableView:(NSIndexPath *)indexPath {
    _searchBar.text = [_suggestionArray objectAtIndex:indexPath.row];
}

- (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText {
    [searchText stringByReplacingOccurrencesOfString:@" " withString:@"+"];
    [searchText stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

    NSLog(@"%@", searchText);

    NSURLSession *session = [NSURLSession sharedSession];
    NSURLSessionDataTask *dataTask = [session dataTaskWithURL:[NSURL URLWithString:[NSString stringWithFormat:@"http://ajax.googleapis.com/ajax/services/search/web?v=1.0&rsz=large&q=%@",searchText]] completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
        NSDictionary *json = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
        NSLog(@"connection test marker");
        NSLog(@"%@", [NSArray arrayWithArray:json[@"responseData"][@"results"]]);
        //_suggestionArray = [NSArray arrayWithArray:[NSArray arrayWithArray:json[@"responseData"][@"results"]]];
        //[_tableView reloadData];
    }];

    [dataTask resume];
}

@end

我还从搜索显示控制器到表视图进行了Ctrl +拖动，并选择了“ searchResultsDelegate”（以防万一，将其放在此处）。

任何帮助将不胜感激。 谢谢！ :)

Answer 1

NSURLSessionDataTask *dataTask = [session dataTaskWithURL:[NSURL URLWithString:[NSString stringWithFormat:@"http://ajax.googleapis.com/ajax/services/search/web?v=1.0&rsz=large&q=%@",searchText]] completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
    NSDictionary *json = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
   if(!json){ // is a valid json ?
   return; 
 }
  NSDictionary * jsonDict = [json objectForKey:@"responseData"];
  _suggestionArray =  = [jsonDict objectForKey:@"results"]

    [_tableView reloadData];
}];

然后更改密钥（例如：“ titleNoFormatting”）

- (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];
}

cell.textLabel.text = [[_suggestionArray objectAtIndex:indexPath.row] valueForKey:@"titleNoFormatting"];

return cell;

}