使用 Objective-C 到 UITableView 的 JSON 数据答案

【问题标题】：JSON data to UITableView using Objective-C使用 Objective-C 到 UITableView 的 JSON 数据
【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

标签： ios objective-c json uitableview

【解决方案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。

【解决方案2】：

key "name" 不会返回一个数组。它将返回 NSString。

【讨论】：

【解决方案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】：

【解决方案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】：

【解决方案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。 :)