Javascript复制实例详解

在做项目时有一个需求，是需要复制内容到剪切板，因为有众多浏览器，所以要兼容性很重要。

1、最简单的copy，只能在IE下使用

使用clipboardData方法

<script type="text/javascript">
function copy(){
window.clipboardData.setData("text",document.getElementById("name").value);
alert("The text is on the clipboard, try to paste it!");
}
</script> 

2、跨浏览器的，但是Firefox无法复制

<head>
<script type="text/javascript">
function CopyToClipboard () {
var input = document.getElementById ("toClipboard");
var textToClipboard = input.value;
var success = true;
if (window.clipboardData) { // Internet Explorer
window.clipboardData.setData ("Text", textToClipboard);
}
else {
// create a temporary element for the execCommand method
var forExecElement = CreateElementForExecCommand (textToClipboard);
/* Select the contents of the element
(the execCommand for 'copy' method works on the selection) */
SelectContent (forExecElement);
var supported = true;
// UniversalXPConnect privilege is required for clipboard access in Firefox
try {
if (window.netscape && netscape.security) {
netscape.security.PrivilegeManager.enablePrivilege ("UniversalXPConnect");
}
// Copy the selected content to the clipboard
// Works in Firefox and in Safari before version 5
success = document.execCommand ("copy", false, null);
}
catch (e) {
success = false;
}
// remove the temporary element
document.body.removeChild (forExecElement);
}
if (success) {
alert ("The text is on the clipboard, try to paste it!");
}
else {
alert ("Your browser doesn't allow clipboard access!");
}
}
function CreateElementForExecCommand (textToClipboard) {
var forExecElement = document.createElement ("div");
// place outside the visible area
forExecElement.style.position = "absolute";
forExecElement.style.left = "-10000px";
forExecElement.style.top = "-10000px";
// write the necessary text into the element and append to the document
forExecElement.textContent = textToClipboard;
document.body.appendChild (forExecElement);
// the contentEditable mode is necessary for the execCommand method in Firefox
forExecElement.contentEditable = true;
return forExecElement;
}
function SelectContent (element) {
// first create a range
var rangeToSelect = document.createRange ();
rangeToSelect.selectNodeContents (element);
// select the contents
var selection = window.getSelection ();
selection.removeAllRanges ();
selection.addRange (rangeToSelect);
}
</script>
</head>
<body>
<input id="toClipboard" value="text to clipboard"/>
<button onclick='CopyToClipboard ()'>Copy text to clipboard</button>
</body>

测试后，Firefox访问失败

3、万能的flash

不要重复造轮子了，有一个使用广泛的类库ZeroClipboard

Zero Clipboard 的实现原理

Zero Clipboard 利用 Flash 进行复制，之前有 Clipboard Copy 解决方案，其利用的是一个隐藏的 Flash。但最新的 Flash Player 10 只允许在 Flash 上进行操作才能启动剪贴板。所以 Zero Clipboard 对此进行了改进，用了一个透明的 Flash ，让其漂浮在按钮之上，这样其实点击的不是按钮而是 Flash ，也就可以使用 Flash 的复制功能了。

创建一个透明的flash

将这个flash浮在按钮上层

确定要复制的文本是什么

监听这个透明flash的鼠标点击事件

该flash被点击之后，完成剪切板处理

对于这几件事，ZeroClipboard分别提供了不同的api，来完成整个需求

如何使用 Zero Clipboard

git clone https://github.com/chenpingzhao/easycopy.git

关于ZeroClipboard.js

var ZeroClipboard = {
version: "1.0.7",
clients: {},
moviePath: "zeroclipboard.swf",
nextId: 1,
$: function(A) {
if (typeof(A) == "string") {
A = document.getElementById(A)
}
if (!A.addClass) {
A.hide = function() {
this.style.display = "none"
};
A.show = function() {
this.style.display = ""
};
A.addClass = function(B) {
this.removeClass(B);
this.className += " " + B
};
A.removeClass = function(D) {
var E = this.className.split(/\s+/);
var B = -1;
for (var C = 0; C < E.length; C++) {
if (E[C] == D) {
B = C;
C = E.length
}
}
if (B > -1) {
E.splice(B, 1);
this.className = E.join(" ")
}
return this
};
A.hasClass = function(B) {
return !!this.className.match(new RegExp("\\s*" + B + "\\s*"))
}
}
return A
},
setMoviePath: function(A) {
this.moviePath = A
},
dispatch: function(D, B, C) {
var A = this.clients[D];
if (A) {
A.receiveEvent(B, C)
}
},
register: function(B, A) {
this.clients[B] = A
},
getDOMObjectPosition: function(C, A) {
var B = {
left: 0,
top: 0,
width: C.width ? C.width : C.offsetWidth,
height: C.height ? C.height : C.offsetHeight
};
while (C && (C != A)) {
B.left += C.offsetLeft;
B.top += C.offsetTop;
C = C.offsetParent
}
return B
},
Client: function(A) {
this.handlers = {};
this.id = ZeroClipboard.nextId++;
this.movieId = "ZeroClipboardMovie_" + this.id;
ZeroClipboard.register(this.id, this);
if (A) {
this.glue(A)
}
}
};
ZeroClipboard.Client.prototype = {
id: 0,
ready: false,
movie: null,
clipText: "",
handCursorEnabled: true,
cssEffects: true,
handlers: null,
//我们可以通过下面这个api，将flash和按钮重叠，且浮在按钮之上
glue: function(D, B, E) {
this.domElement = ZeroClipboard.$(D);
var F = 99;
if (this.domElement.style.zIndex) {
F = parseInt(this.domElement.style.zIndex, 10) + 1
}
if (typeof(B) == "string") {
B = ZeroClipboard.$(B)
} else {
if (typeof(B) == "undefined") {
B = document.getElementsByTagName("body")[0]
}
}
var C = ZeroClipboard.getDOMObjectPosition(this.domElement, B);
this.div = document.createElement("div");
var A = this.div.style;
A.position = "absolute";
A.left = "" + C.left + "px";
A.top = "" + C.top + "px";
A.width = "" + C.width + "px";
A.height = "" + C.height + "px";
A.zIndex = F;
if (typeof(E) == "object") {
for (addedStyle in E) {
A[addedStyle] = E[addedStyle]
}
}
B.appendChild(this.div);
this.div.innerHTML = this.getHTML(C.width, C.height)
},
/*IE 的 Flash JavaScript 通信接口上有一个 bug 。
你必须插入一个 object 标签到一个已存在的 DOM 元素中。并且在写入 innerHTML 之前请确保该元素已经 appendChild 方法插入到 DOM 中*/
getHTML: function(D, A) {
var C = "";
var B = "id=" + this.id + "&width=" + D + "&height=" + A;
if (navigator.userAgent.match(/MSIE/)) {
var E = location.href.match(/^https/i) ? "https://" : "http://";
C += '<object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="' + E + 'download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,0,0" width="' + D + '" height="' + A + '" id="' + this.movieId + '" align="middle"><param name="allowScriptAccess" value="always" /><param name="allowFullScreen" value="false" /><param name="movie" value="' + ZeroClipboard.moviePath + '" /><param name="loop" value="false" /><param name="menu" value="false" /><param name="quality" value="best" /><param name="bgcolor" value="#ffffff" /><param name="flashvars" value="' + B + '"/><param name="wmode" value="transparent"/></object>'
} else {
C += '<embed id="' + this.movieId + '" src="' + ZeroClipboard.moviePath + '" loop="false" menu="false" quality="best" bgcolor="#ffffff" width="' + D + '" height="' + A + '" name="' + this.movieId + '" align="middle" allowScriptAccess="always" allowFullScreen="false" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" flashvars="' + B + '" wmode="transparent" />'
}
return C
},
hide: function() {
if (this.div) {
this.div.style.left = "-2000px"
}
},
show: function() {
this.reposition()
},
destroy: function() {
if (this.domElement && this.div) {
this.hide();
this.div.innerHTML = "";
var A = document.getElementsByTagName("body")[0];
try {
A.removeChild(this.div)
} catch (B) {}
this.domElement = null;
this.div = null
}
},
/* 因为按钮上漂浮有一个 Flash 按钮，所以当页面大小发生变化时，Flash 按钮可能会错位，就点不着了
Zero Clipboard 提供了一个 reposition() 方法，可以重新计算 Flash 按钮的位置。我们可以将它绑定到 resize 事件上
bind(window, "resize", function(){ clip.reposition(); });
function bind(obj, type, fn) {
if (obj.attachEvent) {
obj['e' + type + fn] = fn;
obj[type + fn] = function() {
obj['e' + type + fn](window.event);
}
obj.attachEvent('on' + type, obj[type + fn]);
} else
obj.addEventListener(type, fn, false);
}*/
reposition: function(C) {
if (C) {
this.domElement = ZeroClipboard.$(C);
if (!this.domElement) {
this.hide()
}
}
if (this.domElement && this.div) {
var B = ZeroClipboard.getDOMObjectPosition(this.domElement);
var A = this.div.style;
A.left = "" + B.left + "px";
A.top = "" + B.top + "px"
}
},
setText: function(A) {
this.clipText = A;
if (this.ready) {
this.movie.setText(A)
}
},
addEventListener: function(A, B) {
A = A.toString().toLowerCase().replace(/^on/, "");
if (!this.handlers[A]) {
this.handlers[A] = []
}
this.handlers[A].push(B)
},
setHandCursor: function(A) {
this.handCursorEnabled = A;
if (this.ready) {
this.movie.setHandCursor(A)
}
},
/*鼠标移到按钮上或点击时，由于有 Flash 按钮的遮挡，所以像 css ":hover", ":active" 等伪类可能会失效。
setCSSEffects() 方法就是解决这个问题。首先我们需要将伪类改成类
copy - botton: hover {
border - color: #FF6633;
}

可以改成下面的 ":hover" 改成 ".hover"

copy - botton.hover {
border - color: #FF6633;
}

我们可以调用 clip.setCSSEffects( true ); 这样 Zero Clipboard 会自动为我们处理：将类 .hover 当成伪类 :hover*/

setCSSEffects: function(A) {
this.cssEffects = !! A
},
/*Zero Clipboard 提供了一些事件，你可以自定义函数处理这些事件。
Zero Clipboard 事件处理函数为 addEventListener(); 例如当 Flash 完全载入后会触发一个事件 "load"
clip.addEventListener( "load", function(client) {
alert("Flash 加载完毕！");
});*/
receiveEvent: function(D, E) {
D = D.toString().toLowerCase().replace(/^on/, "");
switch (D) {
case "load":
this.movie = document.getElementById(this.movieId);
if (!this.movie) {
var C = this;
setTimeout(function() {
C.receiveEvent("load", null)
}, 1);
return
}
if (!this.ready && navigator.userAgent.match(/Firefox/) && navigator.userAgent.match(/Windows/)) {
var C = this;
setTimeout(function() {
C.receiveEvent("load", null)
}, 100);
this.ready = true;
return
}
this.ready = true;
this.movie.setText(this.clipText);
this.movie.setHandCursor(this.handCursorEnabled);
break;
case "mouseover":
if (this.domElement && this.cssEffects) {
this.domElement.addClass("hover");
if (this.recoverActive) {
this.domElement.addClass("active")
}
}
break;
case "mouseout":
if (this.domElement && this.cssEffects) {
this.recoverActive = false;
if (this.domElement.hasClass("active")) {
this.domElement.removeClass("active");
this.recoverActive = true
}
this.domElement.removeClass("hover")
}
break;
case "mousedown":
if (this.domElement && this.cssEffects) {
this.domElement.addClass("active")
}
break;
case "mouseup":
if (this.domElement && this.cssEffects) {
this.domElement.removeClass("active");
this.recoverActive = false
}
break
}
if (this.handlers[D]) {
for (var B = 0, A = this.handlers[D].length; B < A; B++) {
var F = this.handlers[D][B];
if (typeof(F) == "function") {
F(this, E)
} else {
if ((typeof(F) == "object") && (F.length == 2)) {
F[0][F[1]](this, E)
} else {
if (typeof(F) == "string") {
window[F](this, E)
}
}
}
}
}
}
}; 

以上所述是小编给大家介绍的Javascript复制实例详解，希望对大家有所帮助。