如何将UIPickerview中的选定行更改为字符串（文本）？

Question

我已为用户选择了UIPickerView来选择他们的感受;生气，快乐，悲伤等。但我无法将他们选择的内容转换为字符串或文本。是否有可能做到这一点？如果不能如何保存他们在选择器中选择的行/选项？

Answer 1

如果我理解你的问题，这里需要的是什么。通过此gitHub commit或download zip

查看项目

1. 使用typedef enum：创建一个包含所有情绪值的枚举;所有人都喜欢分配给每个人的独特价值：
。快乐，好，中立，悲伤，不快乐等等

标题文件

//Number Values for each value of emotion. Add new emotions to the bottom of list, sort will not
//be effected in this declartion
typedef enum : NSUInteger {
    CTEmotionNone = 0,
    CTEmotionHappy = 1,
    CTEmotionOkay = 2,
    CTEmotionNeutral = 3,
    CTEmotionSad = 4,
    CTEmotionUnhappy = 5,
    CTEmotionVeryHappy = 6

} CDEmotions;

1. 将数字值翻译为文字：有不同的方法来做这部分，但我喜欢这个。创建一个内联方法或函数，它将为相应的情感值返回一个字符串：

标题文件

//Here is where the title for each number value will be transalated
static inline NSString * NSEmotionTitleForEmotion( CDEmotions emotion) {
    switch (emotion) {
        case CTEmotionNone:
            return @"Empty"; break;
        case CTEmotionVeryHappy:
            return @"Very Happy"; break;
        case CTEmotionHappy:
            return @"Happy"; break;
        case CTEmotionOkay:
            return @"Okay"; break;
        case CTEmotionNeutral:
            return @"Neutral"; break;
        case CTEmotionSad:
            return @"Sad"; break;
        case CTEmotionUnhappy:
            return @"Unhappy"; break;

    }

}

1. 现在订单：创建另一个内联方法，但这次返回的数组中包含您要显示情感的顺序：

标题文件

//Sorted int values in this array. Sort will be shown here. Do not put text in here, because then
//to know what "Very Happy" is you'll ahve to compare it to a string vs just saying 1 == 1, that
//means CTEmotionHappy
static inline NSArray * NSEmotionsList() {
    return [NSArray arrayWithObjects:
            @(CTEmotionNone),
            @(CTEmotionVeryHappy),
            @(CTEmotionHappy),
            @(CTEmotionOkay),
            @(CTEmotionNeutral),
            @(CTEmotionSad),
            @(CTEmotionUnhappy), nil];

}

现在使用这些函数会很有趣:)我会在你的情况下使用UIPickerViewDataSource中的- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component执行此操作：

的 ViewController.h

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
    return 1;

}

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {
    return [NSEmotionsList() count];

}

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {
    return NSEmotionTitleForEmotion( [[NSEmotionsList() objectAtIndex: row] intValue]);

}

最后实现委托方法- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component：

- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
    [labelEmotion setText: NSEmotionTitleForEmotion( [[NSEmotionsList() objectAtIndex: row] intValue])];

}