可以以编程方式提供 iOS 预测键盘上下文/源文本吗？

Posted 2023-02-24

【中文标题】可以以编程方式提供 iOS 预测键盘上下文/源文本吗？

【英文标题】：Possible to programmatically feed the iOS predictive keyboard context/source text?

【发布时间】：2015-03-05 22:50:44

【问题描述】：

我正在开发一个消息应用程序，并且希望 ios 8 中的预测键盘能够识别正在撰写消息的用户正在回复上一条消息。

所以我希望能够向键盘输入一个字符串，以便为其提供预测上下文。因此，如果用户被问到一个可以解释为极坐标（是/否）的问题，那么预测键盘应该有Yes | No | Maybe

这对开发人员可用吗？

请注意，我不是在谈论自定义键盘，只是为标准键盘提供一些上下文以进行预测。我也不关心实际自定义快速类型回复as in this question。我只是想让键盘知道它在输入什么。

【参考方案1】：

无法将建议严格输入到默认键盘。但是，如果您想为用户提供同等体验，我会使用 myTextView.autocorrectionType = UITextAutocorrectionTypeNo; 隐藏 iOS 建议栏，然后用我自己的模仿建议视图的自定义视图替换该视图。用户输入字符或选择选项后，隐藏自定义建议视图并重新启用 iOS 建议栏。

为此，我将 UIInputView 子类化了（透明度和过渡效果有些差，但其他一切都相当正常工作）。

#import <UIKit/UIKit.h>

@protocol SuggestionViewDelegate <NSObject>

@required
- (void)suggestionSelected:(NSString *)suggestion;

@end

@interface SuggestionView : UIInputView

- (instancetype)init;
- (instancetype)initWithFrame:(CGRect)frame;

/**
 *  The list of suggestions being displayed.
 *  The array contains 0-3 strings.
 *
 *  @return Array of NSString's representing the current suggested strings
 */
- (NSArray *)suggestions;

/**
 *  Add a suggestion to display in the view.
 *  If there are already maxSuggestionCount suggestions, the added suggestion will push one of them out.
 *  If there are already maxSuggestionCount suggestions and the input is 'nil' then the last suggestion will be removed.
 *
 *  @param suggestion String to suggest to the user
 */
- (void)addSuggestion:(NSString *)suggestion;

/**
 *  Removes the suggestion from the list of displayed suggestions.
 *  If the string is not in the set then there is no change made.
 *
 *  @param suggestion NSString to remove from the suggested strings
 */
- (void)removeSuggestion:(NSString *)suggestion;

/**
 *  Takes in either NSArray or NSSet and replaces 'suggestions' with the input. 
 *  Only the first three arguments are recognized.
 *  Objects should be strings. Undefined behavior otherwise.
 *
 *  @param suggestions NSArray or NSSet with 0-3 NSStrings
 */
- (void)setSuggestions:(NSObject *)suggestions;

@property (weak) id <SuggestionViewDelegate> delegate;

/**
 *  The maximum number of suggestions allowed. Default is 3.
 */
@property (nonatomic) NSInteger maxSuggestionCount;

@end

#import "SuggestionView.h"

#define kScreenWidth [UIScreen mainScreen].bounds.size.width

@implementation SuggestionView 
    NSMutableOrderedSet *_suggestions;
    NSMutableArray *_suggestionButtons;


- (instancetype)init 
    self = [self initWithFrame:CGRectMake(0.0f, 0.0f, kScreenWidth, 36.0f)];

    if (self) 

    

    return self;


- (instancetype)initWithFrame:(CGRect)frame 
    self = [super initWithFrame:frame inputViewStyle:UIInputViewStyleKeyboard];

    if (self) 
        _suggestions = [[NSMutableOrderedSet alloc] initWithCapacity:3];
        self.maxSuggestionCount = 3;
        _suggestionButtons = [[NSMutableArray alloc] init];
        self.backgroundColor = [UIColor colorWithWhite:0.0f alpha:0.04f];
    

    return self;


#pragma mark - Modifying Suggestions

- (void)addSuggestion:(NSString *)suggestion 
    if (suggestion) 
        [_suggestions addObject:suggestion];
    

    while (_suggestions.count > self.maxSuggestionCount) 
        [_suggestions removeObjectAtIndex:self.maxSuggestionCount];
    


- (void)removeSuggestion:(NSString *)suggestion 
    [_suggestions removeObject:suggestion];


- (void)setSuggestions:(NSObject *)suggestions 
    if ([suggestions respondsToSelector:@selector(countByEnumeratingWithState:objects:count:)]) 
        [_suggestions removeAllObjects];

        for (NSString *suggestion in (NSArray *)suggestions) 
            if (_suggestions.count < self.maxSuggestionCount) 
                [_suggestions addObject:suggestion];
             else 
                break;
            
        
    


- (NSArray *)suggestions 
    NSMutableArray *suggestionsArray = [[NSMutableArray alloc] initWithCapacity:_suggestions.count];
    for (NSString *suggestion in _suggestions) 
        [suggestionsArray addObject:suggestion];
    

    return suggestionsArray;


#pragma mark - Visual Layout of Suggestions

- (void)layoutSubviews 
    [self layoutSuggestions];


- (void)layoutSuggestions 
    for (UIView *subview in _suggestionButtons) 
        [subview removeFromSuperview];
    

    [_suggestionButtons removeAllObjects];

    for (int i = 0; i < _suggestions.count; i++) 
        NSString *suggestion = _suggestions[i];
        UIButton *suggestionButton = [[UIButton alloc] initWithFrame:CGRectMake(i * self.bounds.size.width/_suggestions.count, 0.0f, self.bounds.size.width/_suggestions.count, self.bounds.size.height)];
        [suggestionButton setTitle:suggestion forState:UIControlStateNormal];
        suggestionButton.titleLabel.adjustsFontSizeToFitWidth = YES;
        suggestionButton.titleLabel.textAlignment = NSTextAlignmentCenter;
        [suggestionButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
        [suggestionButton addTarget:self action:@selector(buttonTouched:) forControlEvents:UIControlEventTouchUpInside];
        [self addSubview:suggestionButton];

        if (i > 0) 
            UIView *whiteLine = [[UIView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 0.5f, self.bounds.size.height)];
            whiteLine.backgroundColor = [UIColor whiteColor];
            [suggestionButton addSubview:whiteLine];
        

        [_suggestionButtons addObject:suggestionButton];
    


#pragma mark - Selecting a Suggestion

- (void)buttonTouched:(UIButton *)button 
    NSTimeInterval animationDuration = 0.09f;
    [UIView animateWithDuration:animationDuration animations:^
        [button setBackgroundColor:[UIColor whiteColor]];

        if ([self.delegate respondsToSelector:@selector(suggestionSelected:)]) 
            [self performSelector:@selector(suggestionSelected:) withObject:button.currentTitle afterDelay:animationDuration * 0.9f];
        

        [button performSelector:@selector(setBackgroundColor:) withObject:[UIColor clearColor] afterDelay:animationDuration];
    ];


- (void)suggestionSelected:(NSString *)suggestion 
    if ([self.delegate respondsToSelector:@selector(suggestionSelected:)]) 
        [self.delegate suggestionSelected:suggestion];
    


@end

要将其实现到您已经子类化的UITextField 或UITextView，请导入 SuggestionView 并实现 SuggestionViewDelegate。然后，在UITextFieldDelegate（或UITextViewDelegate）方法中，添加：

- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField 
    if ([textField isEqual:self.messageTextField]) 
        if (self.suggestionView.suggestions.count > 0 && textField.text.length == 0) 
            textField.inputAccessoryView = self.suggestionView;
            textField.autocorrectionType = UITextAutocorrectionTypeNo;
            [textField reloadInputViews];
        
    

    return YES;


- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string 
    if ([textField isEqual:self.messageTextField]) 
        if (string.length > 0) 
            [self removeSuggestionView];
        
    

    return YES;



- (void)removeSuggestionView 
    self.messageTextField.inputAccessoryView = nil;
    [self.messageTextField setInputAccessoryView:nil];
    self.messageTextField.autocorrectionType = UITextAutocorrectionTypeYes;
    [self.messageTextField reloadInputViews];

    [self.messageTextField performSelector:@selector(resignFirstResponder) withObject:self afterDelay:0.0f];
    [self.messageTextField performSelector:@selector(becomeFirstResponder) withObject:self afterDelay:0.0f];

然后，实现SuggestionViewDelegate:

- (void)suggestionSelected:(NSString *)suggestion 
    [self.messageTextField setText:[NSString stringWithFormat:@"%@%@ ", self.messageTextField.text, suggestion]];
    [self removeSuggestionView];

虽然这不是一个完美的解决方案，但它确实创造了预期的效果。

【讨论】：

虽然我希望有人会突然说：“是的，有可能，只要做 XYZ”，这是一个令人难以置信的答案。感谢您分享您的代码和方法 - 我只是希望 Apple 能够打开它，尽管我认为使用 Messages 而不是 WhatsApp、FB Messenger、Kik 等是一个小胡萝卜

【参考方案2】：

由于现在可以在 Apple 官方文档中找到有关如何执行此操作的更多信息，我想这是不可能的。但是你有两个选择：

保留标准键盘并在其顶部

手动显示一个栏

（在 UIView 实例中）。 从头开始创建您的

自定义键盘

（要困难得多）。你可以read more here。

您还可以考虑完全不同的用户体验。 例如。如果您的用户可能会选择您的建议之一，则仅显示这些建议并保留一个小按钮以输入自定义输入（并在此处关闭键盘）。如果用户可能会输入自定义输入，请参考上述两种选择。

【讨论】：

这是一个伟大而简洁的答案（尽管不是我想听到的答案！啊！！！），所以谢谢。我没有创造赏金，但觉得有义务选择另一个答案作为“最正确的”。我认为完全不同的 UX 不起作用（对我来说，在这种情况下），因为我有意识地尝试做出一个输入，它可以很容易地成为 NLP/对话输入的 2 个按钮。

没问题，希望你能做你需要的其他答案！