如何在 iOS 应用程序中使用 MMPickerView 按年份、型号、制作方式获取 Vehicle API 的层次结构

Posted 2023-02-24

【中文标题】如何在 iOS 应用程序中使用 MMPickerView 按年份、型号、制作方式获取 Vehicle API 的层次结构

【英文标题】：How to get the hierarchy of Vehicle API by year, model, make using MMPickerView for an iOS app

【发布时间】：2015-02-10 14:10:58

【问题描述】：

我使用了 ccpickerview，但现在决定更改为 MMPickerView。但我无法根据所选年份传递车辆品牌和型号的 json 数据。我可以从 jsonData 得到年份。当我点击 Make of the Vehicles 的选择器时，应用程序因此错误而崩溃；

加载

2015-02-10 21:51:22.105 VehicleApp[2099:872363] PostData: year=2013&tag=vehMake
2015-02-10 21:51:22.728 VehicleApp[2099:872363] Response code: 200
2015-02-10 21:51:22.731 Vehicle[2099:872363] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[__NSPlaceholderDictionary initWithObjects:forKeys:count:]: attempt to insert nil object from objects[6]'
*** First throw call stack:

网络服务很好，因为当我使用 CCPickerView 时，条件非常简单“从 json 中拉出的车辆。这就是我想要的

在我之前的 CCPickerView 课程中，我遇到了这种情况；

    - (void)pickerView:(CPPickerView *)pickerView didSelectItem:(NSInteger)item

    if (self.yearsPicker == pickerView) 

        [self setVahicleModel:[self.years objectAtIndex:item]];
        Yyear =[self.years objectAtIndex:item];
    

    if (self.modelPicker == pickerView) 
        Mmake =[self.model objectAtIndex:item];
        [self setVahicle:Mmake Varient:Yyear];

    

    if (self.varientPicker == pickerView) 
        Mmodel =[self.varient objectAtIndex:item];
    

    if (self.insurerPicker == pickerView) 
        Iinsurer =[self.insurer objectAtIndex:item];

    

    if (self.financePicker == pickerView) 
        Ffinance =[self.finance objectAtIndex:item];

    

如何使用 MMPickerView 获得相同的结果？ 这是我的 ViewDidLoad

    - (void)viewDidLoad

    [super viewDidLoad];

    [self setVehicleYear];
    // [self setVehicleMake];
    // [self setVehicleModel];

    _selectedYear = [years objectAtIndex:0];
    _selectedMake = [make objectAtIndex:0];
    _selectedModel = [model objectAtIndex:0];

任何想法或建议我在下面的代码中做错了什么；

    - (IBAction)selectYear:(id)sender 
    //PickerView using array of objects, with selectedObject functionality
    [MMPickerView showPickerViewInView:self.view
                           withObjects:years
                           withOptions:@MMbackgroundColor: [UIColor blackColor],
                                         MMtextColor: [UIColor whiteColor],
                                         MMtoolbarColor: [UIColor blackColor],
                                         MMbuttonColor: [UIColor whiteColor],
                                         MMfont: [UIFont systemFontOfSize:18],
                                         MMvalueY: @3,
                                         MMselectedObject:_selectedYear
                                         
               objectToStringConverter:^NSString *(id object) 
                   return [object description];
               
                            completion:^(id selectedObject) 
                                _lblYear.text = [selectedObject description];
                                _selectedYear = selectedObject;
                            ];




    - (IBAction)selectMake:(id)sender 

    [self setVehicleMake];

    //PickerView using array of objects, with selectedObject functionality
    [MMPickerView showPickerViewInView:self.view
                           withObjects:make
                           withOptions:@MMbackgroundColor: [UIColor blackColor],
                                         MMtextColor: [UIColor whiteColor],
                                         MMtoolbarColor: [UIColor blackColor],
                                         MMbuttonColor: [UIColor whiteColor],
                                         MMfont: [UIFont systemFontOfSize:18],
                                         MMvalueY: @3,
                                         MMselectedObject:_selectedMake
                                         
               objectToStringConverter:^NSString *(id object) 
                   return [object description];
               
                            completion:^(id selectedObject) 
                                _lblMake.text = [selectedObject description];
                                _selectedMake = selectedObject;
                            ];



    - (IBAction)selectModel:(id)sender 
    [self setVehicleModel];
    //PickerView using array of objects, with selectedObject functionality
    [MMPickerView showPickerViewInView:self.view
                           withObjects:model
                           withOptions:@MMbackgroundColor: [UIColor blackColor],
                                         MMtextColor: [UIColor whiteColor],
                                         MMtoolbarColor: [UIColor blackColor],
                                         MMbuttonColor: [UIColor whiteColor],
                                         MMfont: [UIFont systemFontOfSize:18],
                                         MMvalueY: @3,
                                         MMselectedObject:_selectedModel
                                         
               objectToStringConverter:^NSString *(id object) 
                   return [object description];
               
                            completion:^(id selectedObject) 
                                _lblModel.text = [selectedObject description];
                                _selectedModel = selectedObject;
                            ];

【参考方案1】：

这就是我所做的，使用 MMPicketView 并且工作正常，希望这个解决方案对其他人有所帮助。

- (void)viewDidLoad

[super viewDidLoad];
    // Do any additional setup after loading the view.

    [self setVehicleYear];

     selectedYear = [years objectAtIndex:0];
    _selectedInsurer = [insurer objectAtIndex:0];
    _selectedFinance = [finance objectAtIndex:0];

- (void)didReceiveMemoryWarning

    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.

- (IBAction)selectYear:(id)sender 

    //PickerView using array of objects, with selectedObject functionality
    [MMPickerView showPickerViewInView:self.view
                           withObjects:years
                           withOptions:@MMbackgroundColor: [UIColor blackColor],
                                         MMtextColor: [UIColor whiteColor],
                                         MMtoolbarColor: [UIColor blackColor],
                                         MMbuttonColor: [UIColor whiteColor],
                                         MMfont: [UIFont systemFontOfSize:18],
                                         MMvalueY: @3,
                                         MMselectedObject:selectedYear
                                         
               objectToStringConverter:^NSString *(id object) 
                   return [object description];
               
                            completion:^(id selectedObject) 
                                _lblYear.text = [selectedObject description];
                                selectedYear = selectedObject;
                                [self setVehicleMake:selectedYear];
                                selectedMake = [make objectAtIndex:0];
                             ];

- (IBAction)selectMake:(id)sender 
    //PickerView using array of objects, with selectedObject functionality
    [MMPickerView showPickerViewInView:self.view
                           withObjects:make
                           withOptions:@MMbackgroundColor: [UIColor blackColor],
                                         MMtextColor: [UIColor whiteColor],
                                         MMtoolbarColor: [UIColor blackColor],
                                         MMbuttonColor: [UIColor whiteColor],
                                         MMfont: [UIFont systemFontOfSize:18],
                                         MMvalueY: @3,
                                         MMselectedObject:selectedMake
                                         
               objectToStringConverter:^NSString *(id object) 
                   return [object description];
               
                            completion:^(id selectedObject) 
                                _lblMake.text = [selectedObject description];
                                selectedMake = selectedObject;
                                [self setVehicleModel:selectedMake Varient:selectedYear];
                                selectedModel = [varient objectAtIndex:0];
                             ];

- (IBAction)selectModel:(id)sender 
    //PickerView using array of objects, with selectedObject functionality
    [MMPickerView showPickerViewInView:self.view
                           withObjects:varient
                           withOptions:@MMbackgroundColor: [UIColor blackColor],
                                         MMtextColor: [UIColor whiteColor],
                                         MMtoolbarColor: [UIColor blackColor],
                                         MMbuttonColor: [UIColor whiteColor],
                                         MMfont: [UIFont systemFontOfSize:18],
                                         MMvalueY: @3,
                                         MMselectedObject:selectedModel
                                         
               objectToStringConverter:^NSString *(id object) 
                   return [object description];
               
                            completion:^(id selectedObject) 
                                _lblModel.text = [selectedObject description];
                                selectedModel = selectedObject;
                            ];

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