javascript - xul/xpcom 将图像从字符串复制到剪贴板

Question

我不知道如何将图像复制到剪贴板。我的代码如下所示:

var image = "data:image/png;base64,..."

var io         = Components.classes["@mozilla.org/network/io-service;1"].getService(Components.interfaces.nsIIOService);
var channel    = io.newChannel(image, null, null); 
var input      = channel.open();

var trans = Components.classes["@mozilla.org/widget/transferable;1"].createInstance(Components.interfaces.nsITransferable);
trans.addDataFlavor("image/png");
trans.setTransferData("image/png", input, input.available()); 

var clipid = Components.interfaces.nsIClipboard;
var clip   = Components.classes["@mozilla.org/widget/clipboard;1"].getService(clipid);
clip.setData(trans, null, clipid.kGlobalClipboard);

Answer 1

正如 Neil 在新闻组中指出的那样，图像所需的数据是 nsIContainer 实例而不是流。我在网上找不到任何这样做的例子，所以我修改了你的代码:

var image = "data:image/png;base64,...";

var io         = Components.classes["@mozilla.org/network/io-service;1"].getService(Components.interfaces.nsIIOService);
var channel    = io.newChannel(image, null, null);
var input      = channel.open();
var imgTools   = Components.classes["@mozilla.org/image/tools;1"].getService(Components.interfaces.imgITools);

var container  = {};
imgTools.decodeImageData(input, channel.contentType, container);

var trans = Components.classes["@mozilla.org/widget/transferable;1"].createInstance(Components.interfaces.nsITransferable);
trans.addDataFlavor("image/png");
trans.setTransferData("image/png", container.value, -1);

var clipid = Components.interfaces.nsIClipboard;
var clip   = Components.classes["@mozilla.org/widget/clipboard;1"].getService(clipid);
clip.setData(trans, null, clipid.kGlobalClipboard);

对我来说，这会将图像正确地复制到剪贴板。