iOS 独家秘笈教你用TextView轻松实现文本的展开、收起功

要实现效果如图：

IMG_3792.PNG IMG_3793.PNG

核心原理：

先将TextView的linkTextAttributes属性设为空值(超链接默认颜色为蓝色，置空后，添加的富文本颜色才会生效)，然后给正文添加超链接，颜色设为App字体颜色。再给正文后面追加的展开/收起，也添加超链接，富文本颜色设置为蓝色，借助点击超链接代理方法来判断你点的是哪个部分，再通过block实现对应的功能。

注意TextView的初始属性：

_quickTitleTextV = [[CustomTextView alloc] init];
        _quickTitleTextV.font = UISetting_FONT_S(adjustWidth(16));
        _quickTitleTextV.textColor = MWTextColor1;
        _quickTitleTextV.editable = NO;
        _quickTitleTextV.scrollEnabled = NO;
        _quickTitleTextV.linkTextAttributes = @{};//核心代码
        _quickTitleTextV.delegate = self;
        [_quickTitleTextV setTextContainerInset:UIEdgeInsetsZero];
        [self.contentView addSubview:_quickTitleTextV];

展开

_quickTitleTextV.text = [NSString stringWithFormat:@"%@...展开", [contentsubstringWithRange:NSMakeRange(0, textNumber)]];
                NSInteger textLength = _quickTitleTextV.text.length;
                NSMutableAttributedString *attributeStr = [[NSMutableAttributedString alloc] initWithString:_quickTitleTextV.text];
                [attributeStr addAttribute:NSLinkAttributeName value:@"http://click" range:NSMakeRange(0, textLength - 2)];//链接
                [attributeStr addAttribute:NSLinkAttributeName value:@"http://expand" range:NSMakeRange(textLength - 2, 2)];//链接
                [attributeStr addAttribute:NSForegroundColorAttributeName value:MWTextColorBlue range:NSMakeRange(textLength - 2, 2)];
              _quickTitleTextV.attributedText = attributeStr;
                

收起

 _quickTitleTextV.text = [NSString stringWithFormat:@"%@ 收起", content];
            NSInteger textLength = _quickTitleTextV.text.length;
            NSMutableAttributedString *attributeStr = [[NSMutableAttributedString alloc] initWithString:_quickTitleTextV.text];
            [attributeStr addAttribute:NSLinkAttributeName value:@"http://click" range:NSMakeRange(0, textLength - 2)];//链接
            [attributeStr addAttribute:NSLinkAttributeName value:@"http://close" range:NSMakeRange(textLength - 2, 2)];//链接
            [attributeStr addAttribute:NSForegroundColorAttributeName value:MWTextColorBlue range:NSMakeRange(textLength - 2, 2)];
            
           _quickTitleTextV.attributedText = attributeStr;

textView代理方法

- (BOOL)textView:(UITextView *)textView shouldInteractWithURL:(NSURL *)URL inRange:(NSRange)characterRange {
    if ([URL.absoluteString containsString:@"click"]) {
        if (_textViewDicClickBlock) {
            _textViewDicClickBlock();
        }
        return NO;
    }
    
    _model.isExpand = !_model.isExpand;
    if (_expandBlock) {
        _expandBlock();
    }
    
    return NO;
}