使用 Objective-C 到 UITableView 的 JSON 数据
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【中文标题】使用 Objective-C 到 UITableView 的 JSON 数据【英文标题】：JSON data to UITableView using Objective-C 【发布时间】：2015-09-21 10:41:40 【问题描述】：-- 主 JSON 文件的更新问题 --
我正在尝试将名称添加到表格视图中。但桌子总是空的。 （Xcode 7.1b1，ios 9.1b2） 这只是我正在测试我的代码的示例 .json 文件。主 json 文件有更多的数据。
我成功地添加了示例 json 文件中的数据。但是现在使用主json文件后，表又是空的了。
.json 文件
[
"150978":
"jobs":
"D0-C14008-CW":
"05-9032":
"G-05":
"hours_rwk": "False",
"hours_st": "4L",
"hours_ewo_id": "D0-C14008-CWddda",
"hours_ewo": "True",
"hours_dt": "0L",
"hours_ot": "0L",
"comments": ""
,
"05-9031":
"B-02":
"hours_rwk": "False",
"hours_st": "4L",
"hours_ewo_id": "",
"hours_ewo": "False",
"hours_dt": "0L",
"hours_ot": "0L",
"comments": ""
,
"name": "CirilloBetancourt",
"site_id": "D0-C14008-CW",
"trade": "Carpenter",
"note": "",
"signed_in": "True",
"time_in": "08: 30",
"time_out": "16: 30",
"signed_out": "True"
,
"151243":
"jobs": ,
"name": "JasonDiaz",
"site_id": "D0-C14008-CW",
"trade": "Carpenter",
"note": "nowork",
"signed_in": "False",
"time_in": "06: 00",
"time_out": "06: 00",
"signed_out": "False"
,
"151248":
"jobs": ,
"name": "AngelTorresMadrigal",
"site_id": "D0-C14008-CW",
"trade": "Carpenter",
"note": "nowork",
"signed_in": "False",
"time_in": "06: 00",
"time_out": "06: 00",
"signed_out": "False"
,
"151336":
"jobs": ,
"name": "DanielFrey",
"site_id": "D0-C14008-CW",
"trade": "Carpenter",
"note": "nowork",
"signed_in": "False",
"time_in": "06: 00",
"time_out": "06: 00",
"signed_out": "False"
,
"151419":
"jobs":
"D0-C14009-CW1":
"05-9033":
"G-07":
"hours_rwk": "False",
"hours_st": "8L",
"hours_ewo_id": "0",
"hours_ewo": "False",
"hours_dt": "0L",
"hours_ot": "0L",
"comments": ""
,
"D0-C14008-CW":
"05-9031":
"B-02":
"hours_rwk": "False",
"hours_st": "0L",
"hours_ewo_id": "0",
"hours_ewo": "True",
"hours_dt": "0L",
"hours_ot": "2L",
"comments": ""
,
"name": "MikeGullan",
"site_id": "D0-C14008-CW",
"trade": "Carpenter",
"note": "",
"signed_in": "False",
"time_in": "06: 00",
"time_out": "06: 00",
"signed_out": "False"
,
"9990666":
"jobs": ,
"name": "MattStaricha",
"site_id": "D0-C14008-CW",
"trade": "Carpenter",
"note": "nowork",
"signed_in": "False",
"time_in": "06: 00",
"time_out": "06: 00",
"signed_out": "False"
,
"9992610":
"jobs": ,
"name": "MatthewBigelow",
"site_id": "D0-C14008-CW",
"trade": "Carpenter",
"note": "nowork",
"signed_in": "False",
"time_in": "06: 00",
"time_out": "06: 00",
"signed_out": "False"
,
"9992778":
"jobs": ,
"name": "ZhouTan",
"site_id": "D0-C14008-CW",
"trade": "Carpenter",
"note": "nowork",
"signed_in": "False",
"time_in": "06: 00",
"time_out": "06: 00",
"signed_out": "False"
,
"9993273":
"jobs": ,
"name": "RandyFarinelli",
"site_id": "D0-C14008-CW",
"trade": "Carpenter",
"note": "nowork",
"signed_in": "False",
"time_in": "06: 00",
"time_out": "06: 00",
"signed_out": "False"
,
"9996467":
"jobs": ,
"name": "AlvaroSandoval(Guardado)",
"site_id": "D0-C14008-CW",
"trade": "Mason",
"note": "nowork",
"signed_in": "False",
"time_in": "06: 00",
"time_out": "06: 00",
"signed_out": "False"
,
"9996763":
"jobs": ,
"name": "JesusZarate",
"site_id": "D0-C14008-CW",
"trade": "Mason",
"note": "nowork",
"signed_in": "False",
"time_in": "06: 00",
"time_out": "06: 00",
"signed_out": "False"
,
"9996767":
"jobs": ,
"name": "JorgeRomero",
"site_id": "D0-C14008-CW",
"trade": "Mason",
"note": "nowork",
"signed_in": "False",
"time_in": "06: 00",
"time_out": "06: 00",
"signed_out": "False"
,
"9996768":
"jobs":
"D0-C14008-CW":
"05-9032":
"G-05":
"hours_rwk": "False",
"hours_st": "3L",
"hours_ewo_id": "0",
"hours_ewo": "False",
"hours_dt": "0L",
"hours_ot": "0L",
"comments": ""
,
"05-9031":
"B-02":
"hours_rwk": "False",
"hours_st": "5L",
"hours_ewo_id": "0",
"hours_ewo": "False",
"hours_dt": "0L",
"hours_ot": "0L",
"comments": ""
,
"name": "VictorRuiz",
"site_id": "D0-C14008-CW",
"trade": "Mason",
"note": "",
"signed_in": "False",
"time_in": "06: 00",
"time_out": "06: 00",
"signed_out": "False"
,
"9996771":
"jobs": ,
"name": "GabinoMata-Neri",
"site_id": "D0-C14008-CW",
"trade": "Mason",
"note": "nowork",
"signed_in": "False",
"time_in": "06: 00",
"time_out": "06: 00",
"signed_out": "False"
,
"9999247":
"jobs":
"D0-C14008-CW":
"05-9032":
"G-05":
"hours_rwk": "False",
"hours_st": "8L",
"hours_ewo_id": "0",
"hours_ewo": "False",
"hours_dt": "0L",
"hours_ot": "0L",
"comments": ""
,
"05-9031":
"B-02":
"hours_rwk": "True",
"hours_st": "0L",
"hours_ewo_id": "0",
"hours_ewo": "False",
"hours_dt": "0L",
"hours_ot": "1L",
"comments": ""
,
"name": "FranciscoMontez",
"site_id": "D0-C14008-CW",
"trade": "Mason",
"note": "",
"signed_in": "False",
"time_in": "06: 00",
"time_out": "06: 00",
"signed_out": "False"
,
"9999314":
"jobs": ,
"name": "RomanHernandez",
"site_id": "D0-C14008-CW",
"trade": "Mason",
"note": "nowork",
"signed_in": "False",
"time_in": "06: 00",
"time_out": "06: 00",
"signed_out": "False"
]
.h 文件
#import <UIKit/UIKit.h>
@interface TableViewController : UITableViewController
@property (nonatomic, strong) NSArray *nameArray;
@property (nonatomic, strong) NSArray *dict;
@property (nonatomic, strong) NSData *data;
@property (nonatomic, strong) NSString *filePath;
@end
.m 文件
#import "TableViewController.h"
#import "TableViewCell.h"
@interface TableViewController ()
@end
@implementation TableViewController
- (void)viewDidLoad
[super viewDidLoad];
// Uncomment the following line to preserve selection between presentations.
// self.clearsSelectionOnViewWillAppear = NO;
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem;
NSError *error = nil;
_filePath = [[NSBundle mainBundle] pathForResource:@"data" ofType:@"json"];
_data = [NSData dataWithContentsOfFile:_filePath];
_dict = [NSJSONSerialization JSONObjectWithData:_data options:0 error:&error];
- (void)didReceiveMemoryWarning
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
//#warning Incomplete implementation, return the number of sections
return 1;
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
//#warning Incomplete implementation, return the number of rows
return _dict.count;
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
TableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"TableCell" forIndexPath:indexPath];
// Configure the cell...
NSDictionary *dict = _dict[indexPath.row];
NSString *name = dict[@"name"];
cell.titleLabel.text = name;
return cell;
【问题讨论】：
请分享主JSON文件从开始到一些元素 在_nameArray中，你得到了多少计数，你得到了什么结果 【参考方案1】：您的 JSON 实际上格式错误。应该是：
[
"name": "XYZ",
"details": "XYZ"
,
"name": "XYZ",
"details": "XYZ"
]
当您执行_dict = [NSJSONSerialization JSONObjectWithData:_data options:0 error:&error]; 时，您实际得到的是一个字典数组，而不是单个字典。所以调用_nameArray = [_dict objectForKey:@"name"];实际上应该返回nil或者崩溃。
你的实现应该是这样的：
#import "TableViewController.h"
#import "TableViewCell.h"
@interface TableViewController ()
@end
@implementation TableViewController
- (void)viewDidLoad
[super viewDidLoad];
NSError *error = nil;
_filePath = [[NSBundle mainBundle] pathForResource:@"data" ofType:@"json"];
_data = [NSData dataWithContentsOfFile:_filePath];
// Remember here, __dict is an array, I kept the same name as your code but it is NOT a dictionary.
_dict = [NSJSONSerialization JSONObjectWithData:_data options:0 error:&error];
_nameArray = [_dict objectForKey:@"name"];
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
return 1;
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
return _dict.count;
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
TableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"TableCell" forIndexPath:indexPath];
// Remember here, __dict is an array, I kept the same name as your code but it is NOT a dictionary.
NSDictionary *dict = _dict[indexPath.row];
NSString *name = dict[@"name"];
cell.titleLabel.text = name;
return cell;
【讨论】：
我将 .h 文件中的 dict 从 NSDictionary 更改为 NSArray，对我的代码进行了必要的更改，但表仍然是空的！ 你连接控制器作为表视图数据源和委托了吗？ 我用主 json 文件更新了帖子。你能明白为什么数据现在没有显示吗？ @iFlames 问题在于 JSON 的顶部容器是一个数组，其中包含所有值的巨大字典。这意味着您的表视图必须处理作为字典而不是数组的数据源。基本上，顶部的数组容器在某种程度上是无用的，你需要忽略它，只处理它里面的字典。【参考方案2】：key "name" 不会返回一个数组。它将返回 NSString。
【讨论】：
【参考方案3】：您的 JSON 似乎是字典数组。所以这就是你解决问题的方法：
从JSON解析数据时，保存在NSArray：
@property (nonatomic, strong) NSArray *jsonArray;
self.jsonArray = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error];
然后在读取单元格中的数据时，像这样读取它：
NSDictionary *nameDict = self.jsonArray[0];
NSLog(@"Name = %@", nameDict[@"name"]); // This prints Name = XYZ
【讨论】：
【参考方案4】：.json文件的实际格式应该是这样的：
[
"name": "XYZ",
"details": "XYZ"
,
"name": "XYZ",
"details": "XYZ"
]
现在您的 .m 文件应如下所示：
NSError *error = nil;
_filePath = [[NSBundle mainBundle] pathForResource:@"data" ofType:@"json"];
_data = [NSData dataWithContentsOfFile:_filePath];
_dataArray = [NSJSONSerialization JSONObjectWithData:_data options:0 error:&error];
//_nameArray = [_dict objectForKey:@"name"];
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
return _dataArray.count;
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
TableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"TableCell" forIndexPath:indexPath];
NSDictionary *dict = [self.nameArray objectAtIndex:indexPath.row];
cell.titleLabel.text = dict[@“name”];
return cell;
希望这会有所帮助。
【讨论】：
【参考方案5】：- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
TableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"TableCell" forIndexPath:indexPath];
// Configure the cell...
NSString *name = [self.nameArray objectAtIndex:indexPath.row];
cell.titleLabel.text = name;
//NSString *desc = [self.results objectForKey:@""];
return cell;
【讨论】：
嘿@iFlames 检查我的答案，只需替换下面的代码。 :)以上是关于使用 Objective-C 到 UITableView 的 JSON 数据的主要内容，如果未能解决你的问题，请参考以下文章
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