如何在 NSComboBox 上自动完成值答案

【问题标题】：How to autocomplete values on NSComboBox如何在 NSComboBox 上自动完成值
【发布时间】：2014-07-21 22:44:06
【问题描述】：

我正在 Xcode5 中为 MacOS X 开发应用程序

我想在用户键入或删除文本时自动完成在文本字段上键入的选项，例如，如果用户键入“我”，则墨西哥选项会显示在选项列表中，到目前为止，这是我的代码：

@interface ComboNSObject()<NSComboBoxCellDataSource, NSComboBoxDataSource, NSComboBoxDelegate>{
    NSArray *datos;
}

@property (weak) IBOutlet NSComboBox *myCombo;

@end


@implementation ComboNSObject

-(void)awakeFromNib{
    datos = [[NSArray alloc]initWithObjects:@"Mexico",@"Guatemala",@"USA",@"Chile",@"Argentina", nil];

    [_myCombo addItemsWithObjectValues:datos];

}


- (NSString *)comboBox:(NSComboBox *)comboBox completedString:(NSString *)partialString
{
    for (NSString *dataString in datos) {
        NSLog(@"encontrado: %@", [dataString commonPrefixWithString:partialString options:NSCaseInsensitiveSearch]);
    }
    return @"";
}


@end

我已经在我的 NSObjectController 上设置了 _myCombo 及其 NSComboBoxCell 的委托和数据源，但没有任何反应，显示自动完成的正确代码是什么

【问题讨论】：

标签： macos autocomplete nscombobox

【解决方案1】：

分享一个例子，希望对你有帮助：

#import "AppDelegate.h"
@interface AppDelegate() <NSComboBoxDataSource, NSComboBoxDelegate, NSControlTextEditingDelegate>{

    NSMutableArray      *itemsCombo;
    NSMutableArray      *filteredItemsCombo;

}

@property (weak) IBOutlet NSComboBox *myComboBox;

@end


@implementation AppDelegate

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification{

    itemsCombo = [NSMutableArray arrayWithObjects:@"Dog",@"Cat",@"Worm",@"Wolf",@"Werewolf",@"Lion",@"Beast", nil];
    filteredItemsCombo = [[NSMutableArray alloc]initWithArray:itemsCombo];


    _myComboBox.usesDataSource  = YES;
    _myComboBox.completes       = YES;
    _myComboBox.dataSource      = self;
    _myComboBox.delegate        = self;
}


- (NSInteger)numberOfItemsInComboBox:(NSComboBox *)aComboBox{

    return filteredItemsCombo.count;
}


- (id)comboBox:(NSComboBox *)aComboBox objectValueForItemAtIndex:(NSInteger)index{

    return filteredItemsCombo[index];
}


- (NSUInteger)comboBox:(NSComboBox *)aComboBox indexOfItemWithStringValue:(NSString *)string{

    return [filteredItemsCombo indexOfObject:string];
}


-(void)comboBoxWillPopUp:(NSNotification *)notification{
    [self resultsInComboForString:((NSComboBox *)[notification object]).stringValue];
}


-(BOOL)control:(NSControl *)control textView:(NSTextView *)textView doCommandBySelector:(SEL)commandSelector{

    NSComboBox *comboBox = (NSComboBox *) control;

    if (comboBox == _myComboBox && (commandSelector == @selector(insertNewline:) ||
                                    commandSelector == @selector(insertBacktab:) ||
                                    commandSelector == @selector(insertTab:))){
        if ([self resultsInComboForString:comboBox.stringValue].count == 0 ||
             filteredItemsCombo.count == itemsCombo.count) {
            comboBox.stringValue = itemsCombo[0];
        }

    }

    return NO;
}


- (NSString *)comboBox:(NSComboBox *)aComboBox completedString:(NSString *)string {


    NSArray  *currentList = [NSArray arrayWithArray:itemsCombo];

    NSEnumerator *theEnum = [currentList objectEnumerator];
    id eachString;
    NSInteger maxLength = 0;
    NSString *bestMatch = @"";
    while (nil != (eachString = [theEnum nextObject]) )
    {
        NSString *commonPrefix = [eachString
                                  commonPrefixWithString:string options:NSCaseInsensitiveSearch];
        if (commonPrefix.length >= string.length &&
            commonPrefix.length > maxLength)
        {
            maxLength = commonPrefix.length;
            bestMatch = eachString;

            break;
        }
    }

    [self resultsInComboForString:string];

    return bestMatch;
}

-(NSArray *)resultsInComboForString:(NSString *)string{
    [filteredItemsCombo removeAllObjects];

    if (string.length == 0 || [string isEqualToString:@""] || [string isEqualToString:@" "]) {
        [filteredItemsCombo addObjectsFromArray:itemsCombo];
    }
    else{
        for (int i = 0; i < itemsCombo.count; i++) {

            NSRange searchName  = [itemsCombo[i] rangeOfString:string options:NSCaseInsensitiveSearch];
            if (searchName.location != NSNotFound) { [filteredItemsCombo addObject:itemsCombo[i]]; }

        }
    }


    [_myComboBox reloadData];

    return filteredItemsCombo;
}

@end

【讨论】：

我工作得很好，我改进了仅在按键、标签或后退标签上激活验证的代码，谢谢！！！

【解决方案2】：

确保以编程方式将 NSComboBox 的“完成”实例属性设置为 YES，或者您也可以在情节提要编辑器中找到名为“内容自动完成”的复选框。

https://developer.apple.com/documentation/appkit/nscombobox/1436749-completes?language=objc

【讨论】：