将文本插入到光标所在位置的textarea中（JavaScript）

Question

我想创建一个简单的函数，将文本添加到用户光标位置的文本区域。它必须是一个干净的功能。只是基础。我可以找出其余的。

Answer 1

function insertAtCursor(myField, myValue) {

    //IE support

    if (document.selection) {

        myField.focus();

        sel = document.selection.createRange();

        sel.text = myValue;

    }

    //MOZILLA and others

    else if (myField.selectionStart || myField.selectionStart == '0') {

        var startPos = myField.selectionStart;

        var endPos = myField.selectionEnd;

        myField.value = myField.value.substring(0, startPos)

            + myValue

            + myField.value.substring(endPos, myField.value.length);

    } else {

        myField.value += myValue;

    }

}

Answer 2

为了适当的Javascript

HTMLTextAreaElement.prototype.insertAtCaret = function (text) {

  text = text || '';

  if (document.selection) {

    // IE

    this.focus();

    var sel = document.selection.createRange();

    sel.text = text;

  } else if (this.selectionStart || this.selectionStart === 0) {

    // Others

    var startPos = this.selectionStart;

    var endPos = this.selectionEnd;

    this.value = this.value.substring(0, startPos) +

      text +

      this.value.substring(endPos, this.value.length);

    this.selectionStart = startPos + text.length;

    this.selectionEnd = startPos + text.length;

  } else {

    this.value += text;

  }

};