我試圖將選定的字符串包裝在兩個字符之間，例如：選擇“測試”并單擊更改按鈕會將選定的文本更改為“atestb”問題是，我能夠替換選定的文本，但 window.getSelection ().toString() 是空的。這是我使用的功能  replaceSelectedText(startTag, endTag) {    let sel, range;    console.log(window.getSelection().toString())    if (window.getSelection) {      sel = window.getSelection();      if (sel.rangeCount) {        range = sel.getRangeAt(0);        range.deleteContents();        const selectedContent = sel.toString();        console.log("Selected Content ")        console.log(selectedContent)        let replaceDiv = startTag + selectedContent;        replaceDiv=endTag ? replaceDiv + endTag : replaceDiv;        range.insertNode(document.createTextNode(replaceDiv));      }    } else if ((document as any).selection && (document as any).selection.createRange) {      range = (document as any).selection.createRange();      range.text = startTag;    }  }鏈接到 Stackblitz https://stackblitz.com/edit/angular-idyhj5?file=src%2Fapp%2Fapp.component.ts