iOS中表情键盘的完整实现方法详解

@interface PPStickerDataManager : NSObject

  (instancetype)sharedInstance;

/// 所有的表情包
@property (nonatomic, strong, readonly) NSArray<PPSticker *> *allStickers;

/* 匹配给定attributedString中的所有emoji，如果匹配到的emoji有本地图片的话会直接换成本地的图片
*
* @param attributedString 可能包含表情包的attributedString
* @param font 表情图片的对齐字体大小
*/
- (void)replaceEmojiForAttributedString:(NSMutableAttributedString *)attributedString font:(UIFont *)font;
@end

// Presented when object becomes first responder. If set to nil, reverts to following responder chain. If
// set while first responder, will not take effect until reloadInputViews is called.
@property (nullable, readwrite, strong) UIView *inputView;  
@property (nullable, readwrite, strong) UIView *inputAccessoryView;

- (void)changeKeyboardTo:(PPKeyboardType)toType
{
 switch (toType) {
 case PPKeyboardTypeSystem:
  self.textView.inputView = nil; // 切换到系统键盘
  [self.textView reloadInputViews]; // 调用reloadInputViews方法会立刻进行键盘的切换
  break;
 case PPKeyboardTypeSticker:  
  self.textView.inputView = self.stickerKeyboard; // 切换到自定义的表情键盘
  [self.textView reloadInputViews];
  break;
 default:
  break;
 }
}

if (@available(iOS 11.0, *)) { // 只在iOS11及以上才有这个属性
 _textView.textDragInteraction.enabled = NO;
}

@implementation NSAttributedString (PPAddition)

- (NSString *)pp_plainTextForRange:(NSRange)range
{
 if (range.location == NSNotFound || range.length == NSNotFound) {
 return nil;
 }

 NSMutableString *result = [[NSMutableString alloc] init];
 if (range.length == 0) {
 return result;
 }

 NSString *string = self.string;
 [self enumerateAttribute:PPTextBackedStringAttributeName inRange:range options:kNilOptions usingBlock:^(id value, NSRange range, BOOL *stop) {
 PPTextBackedString *backed = value;
 if (backed && backed.string) {
  [result appendString:backed.string];
 } else {
  [result appendString:[string substringWithRange:range]];
 }
 }];
 return result;
}

@end

@implementation NSMutableAttributedString (PPAddition)

- (void)pp_setTextBackedString:(PPTextBackedString *)textBackedString range:(NSRange)range
{
 if (textBackedString && ![NSNull isEqual:textBackedString]) {
 [self addAttribute:PPTextBackedStringAttributeName value:textBackedString range:range];
 } else {
 [self removeAttribute:PPTextBackedStringAttributeName range:range];
 }
}
@end

- (void)cut:(id)sender; // 剪切
- (void)copy:(id)sender; // 复制
- (void)paste:(id)sender; // 黏贴

- (void)cut:(id)sender
{
 // 1.从textView中拿到对应的纯文本，比如：笑死了[笑死]
 NSString *string = [self.attributedText pp_plainTextForRange:self.selectedRange];
 if (string.length) {
 // 2. 将纯文本写入到剪贴板中
 [UIPasteboard generalPasteboard].string = string;

 // 3. 记住当前的光标位置
 NSRange selectedRange = self.selectedRange;
 NSMutableAttributedString *attributeContent = [[NSMutableAttributedString alloc] initWithAttributedString:self.attributedText];
 // 4. 将检测到是表情的文本替换成对应的图片
 [attributeContent replaceCharactersInRange:self.selectedRange withString:@""];
 self.attributedText = attributeContent;
 
 // 5. 重新设置光标
 self.selectedRange = NSMakeRange(selectedRange.location, 0);
 }
}