javascript美化下拉框js

Js代码

1. var childCreate = false;
2. function Offset(e) {
3. //取标签的绝对位置
4. var t = e.offsetTop;
5. var l = e.offsetLeft;
6. var w = e.offsetWidth;
7. var h = e.offsetHeight - 2;
8. while ( e = e.offsetParent) {
9. t += e.offsetTop;
10. l += e.offsetLeft;
11. }
12. return {
13. top : t,
14. left : l,
15. width : w,
16. height : h
17. }
18. }
20. function loadselect(obj) {
21. //第一步：取得select所在的位置
22. var offset = Offset(obj);
23. //第二步：将真的select隐藏
24. obj.style.display = "none";
25. //第三步：虚拟一个div出来代替select
26. var iDiv = document.createElement("div");
27. iDiv.id = "selectof" + obj.name;
28. iDiv.style.position = "absolute";
29. iDiv.style.width = offset.width + "px";
30. iDiv.style.height = offset.height + "px";
31. iDiv.style.top = offset.top + 4 + "px";
32. iDiv.style.left = offset.left + 4 + "px";
33. iDiv.style.background = "url('test.png') no-repeat right -6px";
34. iDiv.style.border = "1px solid #ccc";
35. iDiv.style.fontSize = "12px";
36. iDiv.style.lineHeight = offset.height + "px";
37. iDiv.style.textIndent = "4px";
38. document.body.appendChild(iDiv);
39. //第四步：将select中默认的选项显示出来
40. var tValue = obj.options[obj.selectedIndex].innerHTML;
41. iDiv.innerHTML = tValue;
42. //第五步：模拟鼠标点击
43. iDiv.style.background = "url('images/select.jpg') no-repeat right -2px";
44. iDiv.onclick = function() {//鼠标点击
45. if (document.getElementById("selectchild" + obj.name)) {
46. //判断是否创建过div
47. if (childCreate) {
48. //判断当前的下拉是不是打开状态，如果是打开的就关闭掉。是关闭的就打开。
49. document.getElementById("selectchild" + obj.name).style.display = "none";
50. childCreate = false;
51. } else {
52. document.getElementById("selectchild" + obj.name).style.display = "";
53. childCreate = true;
54. }
55. } else {
56. //初始一个div放在上一个div下边，当options的替身。
57. var cDiv = document.createElement("div");
58. cDiv.id = "selectchild" + obj.name;
59. cDiv.style.position = "absolute";
60. cDiv.style.width = offset.width + "px";
61. cDiv.style.height = obj.options.length * 20 + "px";
62. cDiv.style.top = (offset.top + offset.height + 2) + 4+"px";
63. cDiv.style.left = offset.left + 4+ "px";
64. cDiv.style.background = "#f7f7f7";
65. cDiv.style.border = "1px solid silver";
66. var uUl = document.createElement("ul");
67. uUl.id = "uUlchild" + obj.name;
68. uUl.style.listStyle = "none";
69. uUl.style.margin = "0";
70. uUl.style.padding = "0";
71. uUl.style.fontSize = "12px";
72. cDiv.appendChild(uUl);
73. document.body.appendChild(cDiv);
74. childCreate = true;
75. for (var i = 0; i < obj.options.length; i++) {
76. //将原始的select标签中的options添加到li中
77. var lLi = document.createElement("li");
78. lLi.id = obj.options[i].value;
79. lLi.style.textIndent = "4px";
80. lLi.style.height = "20px";
81. lLi.style.lineHeight = "20px";
82. lLi.innerHTML = obj.options[i].innerHTML;
83. uUl.appendChild(lLi);
84. }
85. var liObj = document.getElementById("uUlchild" + obj.name).getElementsByTagName("li");
86. for (var j = 0; j < obj.options.length; j++) {
87. //为li标签添加鼠标事件
88. liObj[j].onmouseover = function() {
89. this.style.background = "gray";
90. this.style.color = "white";
91. }
92. liObj[j].onmouseout = function() {
93. this.style.background = "white";
94. this.style.color = "black";
95. }
96. liObj[j].onclick = function() {
97. //做两件事情，一是将用户选择的保存到原始select标签中，要不做的再好看表单递交后也获取不到select的值了。
98. obj.options.length = 0;
99. obj.options[0] = new Option(this.innerHTML, this.id);
100. //同时我们把下拉的关闭掉。
101. document.getElementById("selectchild" + obj.name).style.display = "none";
102. childCreate = false;
103. iDiv.innerHTML = this.innerHTML;
104. }
105. }
106. }
107. }
108. }
109. document.body.onload = function (){
110. var selects = document.getElementsByTagName("select");
111. for(var i = 0 ; i < selects.length;i++){
112. loadselect(selects[i]);
113. }
114. }

var childCreate = false;
function Offset(e) {
	//取标签的绝对位置
	var t = e.offsetTop;
	var l = e.offsetLeft;
	var w = e.offsetWidth;
	var h = e.offsetHeight - 2;
	while ( e = e.offsetParent) {
		t += e.offsetTop;
		l += e.offsetLeft;
	}
	return {
		top : t,
		left : l,
		width : w,
		height : h
	}
}

function loadselect(obj) {
	//第一步：取得select所在的位置
	var offset = Offset(obj);
	//第二步：将真的select隐藏
	obj.style.display = "none";
	//第三步：虚拟一个div出来代替select
	var iDiv = document.createElement("div");
	iDiv.id = "selectof" + obj.name;
	iDiv.style.position = "absolute";
	iDiv.style.width = offset.width + "px";
	iDiv.style.height = offset.height + "px";
	iDiv.style.top = offset.top + 4 + "px";
	iDiv.style.left = offset.left + 4 + "px";
	iDiv.style.background = "url('test.png') no-repeat right -6px";
	iDiv.style.border = "1px solid #ccc";
	iDiv.style.fontSize = "12px";
	iDiv.style.lineHeight = offset.height + "px";
	iDiv.style.textIndent = "4px";
	document.body.appendChild(iDiv);
	//第四步：将select中默认的选项显示出来
	var tValue = obj.options[obj.selectedIndex].innerHTML;
	iDiv.innerHTML = tValue;
	//第五步：模拟鼠标点击
	iDiv.style.background = "url('images/select.jpg') no-repeat right -2px";
	iDiv.onclick = function() {//鼠标点击
		if (document.getElementById("selectchild" + obj.name)) {
			//判断是否创建过div
			if (childCreate) {
				//判断当前的下拉是不是打开状态，如果是打开的就关闭掉。是关闭的就打开。
				document.getElementById("selectchild" + obj.name).style.display = "none";
				childCreate = false;
			} else {
				document.getElementById("selectchild" + obj.name).style.display = "";
				childCreate = true;
			}
		} else {
			//初始一个div放在上一个div下边，当options的替身。
			var cDiv = document.createElement("div");
			cDiv.id = "selectchild" + obj.name;
			cDiv.style.position = "absolute";
			cDiv.style.width = offset.width + "px";
			cDiv.style.height = obj.options.length * 20 + "px";
			cDiv.style.top = (offset.top + offset.height + 2) + 4+"px";
			cDiv.style.left = offset.left + 4+ "px";
			cDiv.style.background = "#f7f7f7";
			cDiv.style.border = "1px solid silver";
			var uUl = document.createElement("ul");
			uUl.id = "uUlchild" + obj.name;
			uUl.style.listStyle = "none";
			uUl.style.margin = "0";
			uUl.style.padding = "0";
			uUl.style.fontSize = "12px";
			cDiv.appendChild(uUl);
			document.body.appendChild(cDiv);
			childCreate = true;
			for (var i = 0; i < obj.options.length; i++) {
				//将原始的select标签中的options添加到li中
				var lLi = document.createElement("li");
				lLi.id = obj.options[i].value;
				lLi.style.textIndent = "4px";
				lLi.style.height = "20px";
				lLi.style.lineHeight = "20px";
				lLi.innerHTML = obj.options[i].innerHTML;
				uUl.appendChild(lLi);
			}
			var liObj = document.getElementById("uUlchild" + obj.name).getElementsByTagName("li");
			for (var j = 0; j < obj.options.length; j++) {
				//为li标签添加鼠标事件
				liObj[j].onmouseover = function() {
					this.style.background = "gray";
					this.style.color = "white";
				}
				liObj[j].onmouseout = function() {
					this.style.background = "white";
					this.style.color = "black";
				}
				liObj[j].onclick = function() {
					//做两件事情，一是将用户选择的保存到原始select标签中，要不做的再好看表单递交后也获取不到select的值了。
					obj.options.length = 0;
					obj.options[0] = new Option(this.innerHTML, this.id);
					//同时我们把下拉的关闭掉。
					document.getElementById("selectchild" + obj.name).style.display = "none";
					childCreate = false;
					iDiv.innerHTML = this.innerHTML;
				}
			}
		}
	}
}
document.body.onload = function (){
	var selects = document.getElementsByTagName("select");
	for(var i = 0 ; i < selects.length;i++){
		loadselect(selects[i]);
	}
}