js技巧收集(200多个)(二)【转】
<input type="text" autocomplete="off"> //
134.让下拉框自动下拉
<select onmouseover="javascript:this.size=this.length" onmouseout="javascript:this.size=1">
<option value="">1</option>
<option value="">2</option>
<option value="">3</option>
</select> //
135.读取XML文件
var childrenobj=myselect//document.all.myselect;
var oXMLDoc = new ActiveXObject('MSXML');
oXMLDoc.url = "mymsg.xml";
var oRoot=oXMLDoc.root;
if(oRoot.children != null)
{
for(var i=0;i<oRoot.children.item(0).children.length;++i)
{
oItem = oRoot.children.item(0).children.item(i);
oOption = new Option(oItem.text,oItem.value);
childrenobj.add(oOption);
}
}
//mymsg.xml文件
<?xml version="1.0" encoding="gb2312" ?>
<childrenlist>
<aa>
<child value='3301'>杭州地区</child>
<child value='3303'>温州地区</child>
</aa>
<aa>
<child value='3310'>台州地区</child>
<child value='3311'>丽水地区</child>
</aa>
</childrenlist>//
136.点击图片，图片停止
<a href="javascript:"><img src=http://blog.csdn.net/lxs5i5j/archive/2007/01/22/"http://www.51js.com/images/51js/red_forum.gif" border="0"></a>//
137.显示本地计算机信息
var WshNetwork = new ActiveXObject("WScript.Network");
alert("Domain = " + WshNetwork.UserDomain);
alert("Computer Name = " + WshNetwork.ComputerName);
alert("User Name = " + WshNetwork.UserName);//
138.比较时间
tDate = new Date(2004,01,08,14,35); //年,月，日，时，分
dDate = new Date();
tDate<dDate?alert("早于"):alert("晚于");//
139.弹出鼠标所在处的链结地址
<body onmouseover="if (event.srcElement.tagName=='A')alert(event.srcElement.href)"><a
href=http://blog.csdn.net/lxs5i5j/archive/2007/01/22/"http://51js.com/viewthread.php?tid=13589" >dddd</a><input>//
140.注意不能通过与 undefined 做比较来测试一个变量是否存在，虽然可以检查它的类型是否为“undefined”。在以
下的代码范例中，假设程序员想测试是否已经声明变量 x ：
// 这种方法不起作用
if (x == undefined)
// 作某些操作
// 这个方法同样不起作用- 必须检查
// 字符串 "undefined"
if (typeof(x) == undefined)
// 作某些操作
// 这个方法有效
if (typeof(x) == "undefined")
// 作某些操作
141.创建具有某些属性的对象
var myObject = new Object();
myObject.name = "James";
myObject.age = "22";
myObject.phone = "555 1234";//
142.枚举（循环）对象的所有属性
for (var a in myObject)
{
// 显示 "The property 'name' is James"，等等。
window.alert("The property '" + a + "' is " + myObject[a]);
}//
143.判断一个数字是否是整数
var a=23.2;
alert(a%1==1)//
144.新建日期型变量
var a = new Date(2000, 1, 1);
alert(a.toLocaleDateString());
145.给类定义新的方法
function trim_1()
{
return this.replace(/(^\s*)|(\s*$)/g, "");
}
String.prototype.trim=trim_1;
alert('cindy'.trim());
146.定义一个将日期类型转化为字符串的方法
function guoguo_date()
{
var tmp1,tmp2;
tmp1 =this.getMonth()+1+"";
if(tmp1.length<2)
tmp1="0"+tmp1;
tmp2 =this.getDate()+"";
if(tmp2.length<2)
tmp2="0"+tmp2;
return this.getYear()+"-"+tmp1+"-"+tmp2;
}
Date.prototype.toLiteString=guoguo_date;
alert(new Date().toLiteString())
147. pasta 是有四个参数的构造器,定义对象。
function pasta(grain, width, shape, hasEgg)
{
// 是用什么粮食做的？
this.grain = grain;
// 多宽？（数值）
this.width = width;
// 横截面形状？（字符串）
this.shape = shape;
// 是否加蛋黄？（boolean）
this.hasEgg = hasEgg;
//定义方法
this.toString=aa;
}
function aa()
{
;
}
//定义了对象构造器后，用 new 运算符创建对象实例。
var spaghetti = new pasta("wheat", 0.2, "circle", true);
var linguine = new pasta("wheat", 0.3, "oval", true);
//补充定义属性，spaghetti和linguine都将自动获得新的属性
pasta.prototype.foodgroup = "carbohydrates";
148.打印出错误原因
try
{
x = y // 产生错误。
}
catch(e)
{
document.write(e.description) //打印 "'y' is undefined".
}//
149.生成EXCEL文件并保存
var ExcelSheet;
ExcelApp = new ActiveXObject("Excel.Application");
ExcelSheet = new ActiveXObject("Excel.Sheet");
//本代码启动创建对象的应用程序（在这种情况下，Microsoft Excel 工作表）。一旦对象被创建，就可以用定义的对
象变量在代码中引用它。 在下面的例子中，通过对象变量 ExcelSheet 访问新对象的属性和方法和其他 Excel 对象，
包括 Application 对象和 ActiveSheet.Cells 集合。
// 使 Excel 通过 Application 对象可见。
ExcelSheet.Application.Visible = true;
// 将一些文本放置到表格的第一格中。
ExcelSheet.ActiveSheet.Cells(1,1).Value = "This is column A, row 1";
// 保存表格。
ExcelSheet.SaveAs("C:\\TEST.XLS");
// 用 Application 对象用 Quit 方法关闭 Excel。
ExcelSheet.Application.Quit();//
150.根据标签获得一组对象
var coll = document.all.tags("DIV");
if (coll!=null)
{
for (i=0; i<coll.length; i++)
...
}//
151.实现打印预览及打印
<OBJECT classid="CLSID:8856F961-340A-11D0-A96B-00C04FD705A2" height=0 id=wb name=wb width=0></OBJECT>
<input type=button value=打印预览 onclick="wb.execwb(7,1)">
<input type=button onClick=document.all.wb.ExecWB(6,1) value="打印">//
152.不通过form，直接通过名字引用对象
<INPUT TYPE="text" NAME="gg" value=aaaaa>
<SCRIPT LANGUAGE="JavaScript">
<!--
alert(document.all.gg.value)
//-->
</SCRIPT>//
153.使鼠标滚轮失效
function document.onmousewheel()
{
return false;
}//
154.创建弹出窗口
<SCRIPT LANGUAGE="JScript">
var oPopup = window.createPopup();
var oPopupBody = oPopup.document.body;
oPopupBody.innerHTML = "Display some <B>HTML</B> here.";
oPopup.show(100, 100, 200, 50, document.body);
</SCRIPT>//
155.取得鼠标所在处的对象
var obj = document.elementFromPoint(event.x,event.y);//
156.获得左边的对象
<INPUT TYPE="text" NAME="gg"><INPUT TYPE="text" NAME="bb"
onclick="this.previousSibling.value='guoguo'">//
157.定位鼠标
document.all.hint_layer.style.left = event.x+document.body.scrollLeft+10;
document.all.hint_layer.style.top = event.y+document.body.scrollTop+10;//
158.向下拉框指定位置添加项目
var op = document.createElement("OPTION");
document.all.selected_items.children(index).insertAdjacentElement("BeforeBegin",op);
op.text = document.all.all_items[i].text;
op.value = document.all.all_items[i].value;//
159.判断一个窗口是否已经打开，如果已经打开，则关闭之
var a;
if(a)
a.close();
else
a=window.open('','','');//
160.动态创建一个标签
newElem = document.createElement("DIV");
newElem.id = "hint_layer";
document.body.appendChild(newElem);
document.all.hint_layer.innerText="guoguo";//
161.标题栏
document.title//
162.背景图片
<body style="BACKGROUND-ATTACHMENT: fixed" background="img/bgfix.gif" ></body>//背景图片不动
<STYLE TYPE="text/css">
<!--
BODY {background-image:img/bgchild.jpg;
background-position: center;
background-repeat: no-repeat;
background-attachment: fixed;}
-->
</STYLE>//背景图片居中
163.设置透明效果
document.form.xxx.filters.alpha.opacity=0～100//
164.定义方法
var dragapproved=false;
document.onmouseup=new Function("dragapproved = false");//
165.将数字转化为人民币大写形式
function convertCurrency(currencyDigits) {
// Constants:
var MAXIMUM_NUMBER = 99999999999.99;
// Predefine the radix characters and currency symbols for output:
var CN_ZERO = "零";
var CN_ONE = "壹";
var CN_TWO = "贰";
var CN_THREE = "叁";
var CN_FOUR = "肆";
var CN_FIVE = "伍";
var CN_SIX = "陆";
var CN_SEVEN = "柒";
var CN_EIGHT = "捌";
var CN_NINE = "玖";
var CN_TEN = "拾";
var CN_HUNDRED = "佰";
var CN_THOUSAND = "仟";
var CN_TEN_THOUSAND = "万";
var CN_HUNDRED_MILLION = "亿";
var CN_SYMBOL = "人民币";
var CN_DOLLAR = "元";
var CN_TEN_CENT = "角";
var CN_CENT = "分";
var CN_INTEGER = "整";
// Variables:
var integral; // Represent integral part of digit number.
var decimal; // Represent decimal part of digit number.
var outputCharacters; // The output result.
var parts;
var digits, radices, bigRadices, decimals;
var zeroCount;
var i, p, d;
var quotient, modulus;
// Validate input string:
currencyDigits = currencyDigits.toString();
if (currencyDigits == "") {
alert("Empty input!");
return "";
}
if (currencyDigits.match(/[^,.\d]/) != null) {
alert("Invalid characters in the input string!");
return "";
}
if ((currencyDigits).match(/^((\d{1,3}(,\d{3})*(.((\d{3},)*\d{1,3}))?)|(\d+(.\d+)?))$/) == null) {
alert("Illegal format of digit number!");
return "";
}
// Normalize the format of input digits:
currencyDigits = currencyDigits.replace(/,/g, ""); // Remove comma delimiters.
currencyDigits = currencyDigits.replace(/^0+/, ""); // Trim zeros at the beginning.
// Assert the number is not greater than the maximum number.
if (Number(currencyDigits) > MAXIMUM_NUMBER) {
alert("Too large a number to convert!");
return "";
}
// Process the coversion from currency digits to characters:
// Separate integral and decimal parts before processing coversion:
parts = currencyDigits.split(".");
if (parts.length > 1) {
integral = parts[0];
decimal = parts[1];
// Cut down redundant decimal digits that are after the second.
decimal = decimal.substr(0, 2);
}
else {
integral = parts[0];
decimal = "";
}
// Prepare the characters corresponding to the digits:
digits = new Array(CN_ZERO, CN_ONE, CN_TWO, CN_THREE, CN_FOUR, CN_FIVE, CN_SIX, CN_SEVEN, CN_EIGHT,
CN_NINE);
radices = new Array("", CN_TEN, CN_HUNDRED, CN_THOUSAND);
bigRadices = new Array("", CN_TEN_THOUSAND, CN_HUNDRED_MILLION);
decimals = new Array(CN_TEN_CENT, CN_CENT);
// Start processing:
outputCharacters = "";
// Process integral part if it is larger than 0:
if (Number(integral) > 0) {
zeroCount = 0;
for (i = 0; i < integral.length; i++) {
p = integral.length - i - 1;
d = integral.substr(i, 1);
quotient = p / 4;
modulus = p % 4;
if (d == "0") {
zeroCount++;
}
else {
if (zeroCount > 0)
{
outputCharacters += digits[0];
}
zeroCount = 0;
outputCharacters += digits[Number(d)] + radices[modulus];
}
if (modulus == 0 && zeroCount < 4) {
outputCharacters += bigRadices[quotient];
}
}
outputCharacters += CN_DOLLAR;
}
// Process decimal part if there is:
if (decimal != "") {
for (i = 0; i < decimal.length; i++) {
d = decimal.substr(i, 1);
if (d != "0") {
outputCharacters += digits[Number(d)] + decimals[i];
}
}
}
// Confirm and return the final output string:
if (outputCharacters == "") {
outputCharacters = CN_ZERO + CN_DOLLAR;
}
if (decimal == "") {
outputCharacters += CN_INTEGER;
}
outputCharacters = CN_SYMBOL + outputCharacters;
return outputCharacters;
}//
