JavaScript在光标处插入文字

example.js

// JS脚本区域
function insertAtCursor(myField, myValue) {
  //IE support
  if (document.selection) {
    document.selection.empty();
    caretPos.text = myValue;
    caretPos.select();
    myField.focus();
  }
  //MOZILLA/NETSCAPE support
  else if (myField.selectionStart || myField.selectionStart == '0') {
    var startPos = myField.selectionStart;
    var endPos = myField.selectionEnd;
    // save scrollTop before insert
    var restoreTop = myField.scrollTop;
    myField.value = myField.value.substring(0, startPos) + myValue + myField.value.substring(endPos, myField.value.length);
    if (restoreTop > 0) {
      myField.scrollTop = restoreTop;
    }
    myField.focus();
    myField.selectionStart = startPos + myValue.length;
    myField.selectionEnd = startPos + myValue.length;
  } else {
    myField.value += myValue;
    myField.focus();
  }
}

var caretPos ;
function setPos(){
  if (document.selection) { //IE
    caretPos =  document.selection.createRange();
  }
}

// HTML区域
<textarea id="input" οnchange="setPos()" οnfοcus="setPos()"></textarea>


// 示例：
var ipt = document.getElementById("input");
insertAtCursor(ipt,value["value"]);