objective-c - 处理 NSTokenField 中的重复选择

Question

如何防止从 NSTokenField 中的数组中重复选择。我已经实现了委托(delegate)completionsForSubstring。

Answer 1

我能够用这种方法删除任何重复项，这确实有点hacky，但它有效:

// Be sure to set the delegate of your NSTokenfield either in IB or in code.


#pragma mark - NSTokenFieldDelegate
-(NSArray *)tokenField:(NSTokenField *)tokenField shouldAddObjects:(NSArray *)tokens atIndex:(NSUInteger)index{

    double delayInSeconds = .1;
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
    dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
        NSArray *aray = [tokenField objectValue];
        NSOrderedSet *set = [NSOrderedSet orderedSetWithArray:aray];
        aray = [set array];
        [tokenField setObjectValue:aray];

    });

    return tokens;
}