如何使用nsattributedstring在Swift中将图像添加为文本附件

Question

我正在尝试使用我作为按钮放入的图像为iOS构建自定义键盘.当我按下按钮时,链接到该按钮的图像被放入一个属性字符串,该字符串被加载到自定义键盘视图内的UiTextView中.那很有效.

问题是,当我将新图像附加到属性字符串时,字符串中的旧图像和新图像都将更改为我当前按下的图像.我无法理解为什么字符串中的旧图像正在发生变化.

有什么建议？我已经尝试使用replaceCharactersInRange和insertAttributedString但无法使其工作.这是代码(在viewDidLoad之后):

let textAttachment = NSTextAttachment()

let textView = UITextView(frame: CGRectMake(5, 5, 200, 40))
var attributedString = NSMutableAttributedString(string: "")

@IBAction func buttonPressed(button :UIButton) {

    let string = button.titleLabel?.text

    textAttachment.image = UIImage(named: "\(string!).png")!
    textAttachment.image = UIImage(CGImage: textAttachment.image!.CGImage!, scale: 6, orientation: .Up)
    let attrStringWithImage = NSAttributedString(attachment: textAttachment)
    attributedString.appendAttributedString(attrStringWithImage);


    textView.attributedText = attributedString;
  }

谢谢!

Answer 1

我们不能简单地附加 NSTextAttachment 图像。我们必须将所有附加图像和串联存储到现有的属性字符串中。

func buttonPressed(_ sender: Any) {

    let  button = sender as! UIButton
    let tag =  button.tag
    let attributedString:NSAttributedString!

    switch tag {
    case 2:
        attributedString = addAttributedText(text: (button.titleLabel?.text)!)
    case 3:
        attributedString = addAttributedText(text: (button.titleLabel?.text)!)
    case 4:
        attributedString = addAttributedText(text: (button.titleLabel?.text)!)
    default:
       attributedString = addAttributedText(text: "launch")
      }
        textView.attributedText = attributedString
    }

    func addAttributedText(text:String) -> NSAttributedString {
        textViewDidChange(textView)
        let axtractedImageAttribute = NSMutableAttributedString()
        for image in imageArray {
            let attachment:NSTextAttachment = NSTextAttachment()
            attachment.image = image
            attachment.setImageHeight(height: 20)
            let attachmentString:NSAttributedString = NSAttributedString(attachment: attachment)
            axtractedImageAttribute.append(attachmentString)
        }

        let attachment:NSTextAttachment = NSTextAttachment()
        attachment.image = UIImage(named: "\(text).png")
        attachment.setImageHeight(height: 20)
        let attachmentString:NSAttributedString = NSAttributedString(attachment: attachment)
        let attributedString:NSMutableAttributedString = NSMutableAttributedString(string:textView.text!)
        attributedString.append(axtractedImageAttribute)
        attributedString.append(attachmentString)
        return attributedString
    }

    //MARKS:-  Extract attachedImage
    func textViewDidChange(_ textView: UITextView)  {
        imageArray = [UIImage]()
        let range = NSRange(location: 0, length: textView.attributedText.length)
        if (textView.textStorage.containsAttachments(in: range)) {
            let attrString = textView.attributedText
            var location = 0
            while location < range.length {
                var r = NSRange()
                let attrDictionary = attrString?.attributes(at: location, effectiveRange: &r)
                if attrDictionary != nil {
                    let attachment = attrDictionary![NSAttachmentAttributeName] as? NSTextAttachment
                    if attachment != nil {
                        if attachment!.image != nil {
                            imageArray.append( attachment!.image!)
                        }
                    }
                    location += r.length
                }
            }
        }
    }

}

演示参考

Answer 2

我发现了问题，我需要为 NSTextAttachment 使用不同的变量（即 textAttachment1、textAttachment2 等），否则它只使用已解决的第一个图像。