Objective C如何根据其他数组项从数组中删除项

Posted 2023-03-10

【中文标题】Objective C如何根据其他数组项从数组中删除项

【英文标题】：Objective C how to remove items from array based on other arrays items

【发布时间】：2020-04-21 09:43:52

【问题描述】：

我有三个 UIPickerviews。我有一个json响应。我有一个三个文本字段。如果用户选择第一个选择器视图，则相关数据将显示在第一个文本字段中。第二个和第三个选择器视图也相同。我的要求是如果用户在第一个选择器视图中选择特定项目，第二个和第三个选择器视图不显示该项目。第二和第三也一样。

-(void)viewDidLoad

    dataArray = [[NSMutableArray alloc]initWithObjects:@"A+",@"A-",@"B+",@"B-",@"O+",@"O-", nil];

    bloodGroup = [[UITextField alloc]initWithFrame:CGRectMake(10, logoImg.frame.origin.y+logoImg.frame.size.height+45, screenWidth-20, 50)];

    bloodGroup.borderStyle = UITextBorderStyleRoundedRect;
    bloodGroup.font = [UIFont systemFontOfSize:15];
    bloodGroup.placeholder = @"Please Select Your Option";
    bloodGroup.delegate = self;

    [self.view addSubview:bloodGroup];

    txtField1 = [[UITextField alloc]initWithFrame:CGRectMake(10, ansField1.frame.origin.y+ansField1.frame.size.height+45, screenWidth-20, 50)];
    txtField1.borderStyle = UITextBorderStyleRoundedRect;
    txtField1.font = [UIFont systemFontOfSize:15];
    txtField1.placeholder = @"Please Select Your Option";
    txtField1.delegate = self;

    [self.view addSubview:txtField1];

    txtField2 = [[UITextField alloc]initWithFrame:CGRectMake(10, ansField2.frame.origin.y+ansField2.frame.size.height+45, screenWidth-20, 50)];
    txtField2.borderStyle = UITextBorderStyleRoundedRect;
    txtField2.font = [UIFont systemFontOfSize:15];
    txtField2.placeholder = @"Please Select Your Option";
    txtField2.delegate = self;

    [self.view addSubview:txtField2];

    myPickerView = [[UIPickerView alloc] init];
    [myPickerView setDataSource: self];
    [myPickerView setDelegate: self];
    myPickerView.showsSelectionIndicator = YES;

    bloodGroup.inputView = myPickerView;
    bloodGroup.inputAccessoryView = toolBar;

    // txtField1

    txtField1.inputView = myPickerView;
    txtField1.inputAccessoryView = toolBar;

    txtField2.inputView = myPickerView;
    txtField2.inputAccessoryView = toolBar;


-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView 

    if (isBloodGroupFieldSelected) 
        return 1;
    
    else if(!isBloodGroupFieldSelected)
        return 1;
    
    else if(!isGenderGroupFieldSelected)
    
        return 1;
    
    return 0;


-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component


    if (isBloodGroupFieldSelected) 
        return [dataArray count];
    
    else if(!isBloodGroupFieldSelected)
    
        return [dataArray count];
    
    else if (!isGenderGroupFieldSelected)
    
        return [dataArray count];
    
    return 0;


-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component 

  if (isBloodGroupFieldSelected)
    
        return dataArray[row];
    
    else if((!isBloodGroupFieldSelected) && (isGenderGroupFieldSelected))
    
        return dataArray[row];
    
    else if(!isGenderGroupFieldSelected)
    
        return dataArray[row];
    
    return 0;


-(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component 

    if (isBloodGroupFieldSelected) 
        bloodGroup.text = dataArray[row];
    
    else if((!isBloodGroupFieldSelected) && (isGenderGroupFieldSelected))
    
        txtField1.text = dataArray[row];
    
    else if(!isGenderGroupFieldSelected)
    
        txtField2.text= dataArray[row];
    


- (void)textFieldDidBeginEditing:(UITextField *)textField 

    if (textField == bloodGroup) 
        isBloodGroupFieldSelected = YES;
    
    else if (textField == txtField1)
        isBloodGroupFieldSelected = NO;
        isGenderGroupFieldSelected = YES;
    
    else if (textField == txtField2) 
        isGenderGroupFieldSelected = NO;
        isBloodGroupFieldSelected = NO;
    
    [myPickerView reloadAllComponents];

【参考方案1】：

您已经拥有了大部分所需的代码。 pickerView:didSelectRow:inComponent: 委托方法将在您的任何选择器已更改时被调用，假设它们每个都将其委托设置为上面的控制器。虽然，我只看到上面代码中定义的一个选择器视图。假设您的选择器视图名为myPickerView、myPickerView2 和myPickerView3。代码大概是：

- (void)pickerView:(UIPickerView *)pickerView
      didSelectRow:(NSInteger)row
       inComponent:(NSInteger)component

    if (pickerView == pickerView1) 
        // the first picker view lseection has changed
        // update myPickerView2 and myPickerView3 to reflect
        // the values you want based on this selection
     else if (pickerView == pickerView2) 
        // update the other views based on this selection
     else ...

    ....

【讨论】：

感谢您的回复。但我正在使用单个选择器视图。请解释完整的代码。