好的,我找到了解决方案...
首先,请求必须覆盖return 类型为x-user-defined
xhr.overrideMimeType('text\/plain; charset=x-user-defined');
之后,浏览器不会触及数据。
使用以下 Base64 编码器
Base64 = {
// private property
_keyStr: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
encodeBinary: function (input) {
var output = "";
var bytebuffer;
var encodedCharIndexes = new Array(4);
var inx = 0;
var paddingBytes = 0;
while (inx < input.length) {
// Fill byte buffer array
bytebuffer = new Array(3);
for (jnx = 0; jnx < bytebuffer.length; jnx++)
if (inx < input.length)
bytebuffer[jnx] = input.charCodeAt(inx++) & 0xff; // throw away high-order byte, as documented at: https://developer.mozilla.org/En/Using_XMLHttpRequest#Handling_binary_data
else
bytebuffer[jnx] = 0;
// Get each encoded character, 6 bits at a time
// index 1: first 6 bits
encodedCharIndexes[0] = bytebuffer[0] >> 2;
// index 2: second 6 bits (2 least significant bits from input byte 1 + 4 most significant bits from byte 2)
encodedCharIndexes[1] = ((bytebuffer[0] & 0x3) << 4) | (bytebuffer[1] >> 4);
// index 3: third 6 bits (4 least significant bits from input byte 2 + 2 most significant bits from byte 3)
encodedCharIndexes[2] = ((bytebuffer[1] & 0x0f) << 2) | (bytebuffer[2] >> 6);
// index 3: forth 6 bits (6 least significant bits from input byte 3)
encodedCharIndexes[3] = bytebuffer[2] & 0x3f;
// Determine whether padding happened, and adjust accordingly
paddingBytes = inx - (input.length - 1);
switch (paddingBytes) {
case 2:
// Set last 2 characters to padding char
encodedCharIndexes[3] = 64;
encodedCharIndexes[2] = 64;
break;
case 1:
// Set last character to padding char
encodedCharIndexes[3] = 64;
break;
default:
break; // No padding - proceed
}
// Now we will grab each appropriate character out of our keystring
// based on our index array and append it to the output string
for (jnx = 0; jnx < encodedCharIndexes.length; jnx++)
output += this._keyStr.charAt(encodedCharIndexes[jnx]);
}
return output;
}
};
Mozilla发布了一些神奇的东西,它没有让我正确编码这些东西
bytebuffer[jnx] = input.charCodeAt(inx++) & 0xff
最终的代码看起来像这样......
oauth.authorize(function () {
var method = "GET", params = {}, url = photo.href;
var nxhr = new XMLHttpRequest();
nxhr.onreadystatechange = function (data) {
if (nxhr.readyState == 4) {
console.log("<img src='data:image/*;base64," + Base64.encodeBinary(nxhr.response) + "' />");
}
};
nxhr.open(method, url, true);
nxhr.setRequestHeader('GData-Version', '3.0');
nxhr.setRequestHeader('Authorization', oauth.getAuthorizationHeader(url, method, params));
nxhr.overrideMimeType('text\/plain; charset=x-user-defined');
});
PS如果直接把“data:image/*”放到浏览器窗口,会下载文件,打不开。但是,如果您将其直接放入 img src 中,它就可以正常工作!