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function displayHtmlWithImageStream(bodyHtml) {
var imgReg = /<img.*?(?:>|\/>)/gi;
var arr = bodyHtml.match(imgReg);
if (arr != null) {
for (var i = 0; i < arr.length; i++) {
replaceImageUrlWithStream(bodyHtml, arr, i);
}
}
}
function replaceImageUrlWithStream(bodyHtml, arr, i) {
$scope.body = bodyHtml;
var images = arr[i];
var srcReg = /src=[\‘\"]?([^\‘\"]*)[\‘\"]?/i;
var src = images.match(srcReg);
var url = src[1];
var type = ‘image/‘ + url.split(‘.‘).pop();
var imgDataObject = {};
assetHelper.getAsset(url, imgDataObject, getAssetSuccess, getAssetError);
function getAssetSuccess(data) {
var imgDataUrl = data.url;
$scope.body = $scope.body.replace(url, ‘data:‘ + type + ‘;base64,‘ + imgDataUrl);
}
}
function getAssetError(url, reason) {
$scope.body = $scope.body.replace(url, ‘#‘);
}
function getAsset(url, assetModel, success, fail) {
serviceBase.get({ url: url, responseType: ‘arraybuffer‘ })
.success(function (response) {
assetModel.url = base64ArrayBuffer(response);
success(assetModel);
})
.error(function (url, reason) {
fail(url, reason);
});
}
// Converts an ArrayBuffer directly to base64, without any intermediate ‘convert to string then
// use window.btoa‘ step. According to my tests, this appears to be a faster approach:
// http://jsperf.com/encoding-xhr-image-data/5
function base64ArrayBuffer(arrayBuffer) {
var base64 = ‘‘;
var encodings = ‘ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/‘;
var bytes = new Uint8Array(arrayBuffer);
var byteLength = bytes.byteLength;
var byteRemainder = byteLength % 3;
var mainLength = byteLength - byteRemainder;
var a, b, c, d;
var chunk;
// Main loop deals with bytes in chunks of 3
for (var i = 0; i < mainLength; i = i + 3) {
// Combine the three bytes into a single integer
chunk = (bytes[i] << 16) | (bytes[i + 1] << 8) | bytes[i + 2];
// Use bitmasks to extract 6-bit segments from the triplet
a = (chunk & 16515072) >> 18; // 16515072 = (2^6 - 1) << 18
b = (chunk & 258048) >> 12; // 258048 = (2^6 - 1) << 12
c = (chunk & 4032) >> 6; // 4032 = (2^6 - 1) << 6
d = chunk & 63; // 63 = 2^6 - 1
// Convert the raw binary segments to the appropriate ASCII encoding
base64 += encodings[a] + encodings[b] + encodings[c] + encodings[d];
}
// Deal with the remaining bytes and padding
if (byteRemainder == 1) {
chunk = bytes[mainLength];
a = (chunk & 252) >> 2; // 252 = (2^6 - 1) << 2
// Set the 4 least significant bits to zero
b = (chunk & 3) << 4; // 3 = 2^2 - 1
base64 += encodings[a] + encodings[b] + ‘==‘;
} else if (byteRemainder == 2) {
chunk = (bytes[mainLength] << 8) | bytes[mainLength + 1];
a = (chunk & 64512) >> 10; // 64512 = (2^6 - 1) << 10
b = (chunk & 1008) >> 4; // 1008 = (2^6 - 1) << 4
// Set the 2 least significant bits to zero
c = (chunk & 15) << 2; // 15 = 2^4 - 1
base64 += encodings[a] + encodings[b] + encodings[c] + ‘=‘;
}
return base64;
}
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原文地址：http://www.cnblogs.com/xiaxianfei/p/5291618.html
