相关function

在NSComboBoxDataSource中包含有如下的function

/* These two methods are required when not using bindings */
- (NSInteger)numberOfItemsInComboBox:(NSComboBox *)comboBox;   // 返回CombBox显示的数量
- (nullable id)comboBox:(NSComboBox *)comboBox objectValueForItemAtIndex:(NSInteger)index;    // 返回ComboBox显示的内容

- (NSUInteger)comboBox:(NSComboBox *)comboBox indexOfItemWithStringValue:(NSString *)string;    // 高亮已选的item
- (nullable NSString *)comboBox:(NSComboBox *)comboBox completedString:(NSString *)string; // 与`Autocompletes`相配合，实现类似自动查找的功能

在NSComboBoxDelegate中包含的function

/* Notifications */
- (void)comboBoxWillPopUp:(NSNotification *)notification;
- (void)comboBoxWillDismiss:(NSNotification *)notification;
- (void)comboBoxSelectionDidChange:(NSNotification *)notification;
- (void)comboBoxSelectionIsChanging:(NSNotification *)notification;

需求：

首先会在UI上创建两个NSComboBox，然后通过获取配置的plist的值分别显示在UI上

• 创建的用户界面如下图，并且将这两个NSComboBox的identifier分别设置为value1和value2，然后再勾选Uses Data Source:

用户界面

设置NSComboBox的identifier

勾选`Uses Data Source`

• 拖拽NSComboBox的dataSource与View Controller进行相关联
  

• 接下来就是代码部分，先要遵循协议NSComboBoxDataSource，具体实现如下代码：

- (void)viewDidLoad {
    [super viewDidLoad];
    self.valueContent = [[NSDictionary alloc] initWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"value" ofType:@"plist"]];
}

#pragma mark -----------ComboBox function part-------------
- (NSInteger)numberOfItemsInComboBox:(NSComboBox *)comboBox {
    NSInteger num = 0;
    if ([comboBox.identifier isEqualToString:@"value1"]) {
        num = [[self.valueContent objectForKey:@"value1"] count];
    }else if ([comboBox.identifier isEqualToString:@"value2"]) {
        num = [[self.valueContent objectForKey:@"value2"] count];
    }

    return num;
}

- (nullable id)comboBox:(NSComboBox *)comboBox objectValueForItemAtIndex:(NSInteger)index {
    NSArray *comboBoxValue = [[NSArray alloc] init];
    if ([comboBox.identifier isEqualToString:@"value1"]) {
        comboBoxValue = [self.valueContent objectForKey:@"value1"];
    }else if ([comboBox.identifier isEqualToString:@"value2"]) {
        comboBoxValue = [self.valueContent objectForKey:@"value2"];
    }
    
    return [comboBoxValue objectAtIndex:index];
}

• 最后效果图：
  效果图

其他

selectItemAtIndex:选择NSComboBox的默认值

- (NSUInteger)comboBox:(NSComboBox *)comboBox indexOfItemWithStringValue:(NSString *)string {
    NSInteger num = 0;
    num = self.valueOfUART.indexOfSelectedItem;
    
    return num;
}