在jquery

Question

我使用下面的jquery函数来格式化文本框值以创建类似于＆＃34;（123）456-7890＆＃34;的移动格式。

当我修改文本框值时，光标指向文本框的最后位置。

如何才能将其修复到应该存在的特定位置。

  $("body").on("input propertychange", ".USMobileFormat", function (e) {
        $(this).attr('maxlength', '14');
        if (e.which != 8 && e.which != 0 && (e.which < 48 || e.which > 57 || $(this).val().length >= 14)) {
            return false;
        }          
        var input = this.value.replace(/[^0-9\(\)\s\-]/g, "");
        var inputlen = input.length;
        // Get just the numbers in the input
        var numbers = this.value.replace(/\D/g, '');
        var numberslen = numbers.length;
        // Value to store the masked input
        var newval = "";

        //Loop through the existing numbers and apply the mask
        for (var i = 0; i < numberslen; i++) {
            if (i == 0) newval = "(" + numbers[i];
            else if (i == 3) newval += ") " + numbers[i];
            else if (i == 6) newval += "-" + numbers[i];
            else newval += numbers[i];
        }

        // Re-add the non-digit characters to the end of the input that the user entered and that match the mask.
        if (inputlen >= 1 && numberslen == 0 && input[0] == "(") newval = "(";
        else if (inputlen >= 6 && numberslen == 3 && input[4] == ")" && input[5] == " ") newval += ") ";
        else if (inputlen >= 5 && numberslen == 3 && input[4] == ")") newval += ")";
        else if (inputlen >= 6 && numberslen == 3 && input[5] == " ") newval += " ";
        else if (inputlen >= 10 && numberslen == 6 && input[9] == "-") newval += "-";
        var position = setTimeout(function () { doGetCaretPosition(this); }, 300);
        $(this).val(newval.substring(0, 16));
        setTimeout(function () { setCaretPosition(this, position); }, 300);
    });


function doGetCaretPosition(ctrl) {    
    var CaretPos = 0;
    if (ctrl.selectionStart || ctrl.selectionStart == 0) {// Standard.
        CaretPos = ctrl.selectionStart;
    }
    else if (document.selection) {// Legacy IE
        ctrl.focus();
        var Sel = document.selection.createRange();
        Sel.moveStart('character', -ctrl.value.length);
        CaretPos = Sel.text.length;
    }
    return (CaretPos);
}
function setCaretPosition(ctrl, pos) {
    if (ctrl.setSelectionRange) {
        ctrl.focus();
        ctrl.setSelectionRange(pos, pos);
    }
    else if (ctrl.createTextRange) {
        var range = ctrl.createTextRange();
        range.collapse(true);
        range.moveEnd('character', pos);
        range.moveStart('character', pos);
        range.select();
    }
}