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HTML5 Blob与ArrayBuffer、TypeArray和字符串String之间转换

1.将String字符串转换成Blob对象

//将字符串 转换成 Blob 对象var blob = new Blob(["Hello World!"], {    type: ‘text/plain‘});console.info(blob);console.info(blob.slice(1, 3, ‘text/plain‘));

2.将TypeArray  转换成 Blob 对象

//将 TypeArray  转换成 Blob 对象var array = new Uint16Array([97, 32, 72, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100, 33]);//测试成功//var blob = new Blob([array], { type: "application/octet-binary" });//测试成功var blob = new Blob([array]);//将 Blob对象 读成字符串var reader = new FileReader();reader.readAsText(blob, ‘utf-8‘);reader.onload = function (e) {    console.info(reader.result); //a Hello world!}

3,将Blob对象转换成String字符串,使用FileReader的readAsText方法

//将字符串转换成 Blob对象var blob = new Blob([‘中文字符串‘], {    type: ‘text/plain‘});//将Blob 对象转换成字符串var reader = new FileReader();reader.readAsText(blob, ‘utf-8‘);reader.onload = function (e) {    console.info(reader.result);}

4.将Blob对象转换成ArrayBuffer,使用FileReader的 readAsArrayBuffer方法

//将字符串转换成 Blob对象var blob = new Blob([‘中文字符串‘], {    type: ‘text/plain‘});//将Blob 对象转换成 ArrayBuffervar reader = new FileReader();reader.readAsArrayBuffer(blob);reader.onload = function (e) {    console.info(reader.result); //ArrayBuffer {}    //经常会遇到的异常 Uncaught RangeError: byte length of Int16Array should be a multiple of 2    //var buf = new int16array(reader.result);    //console.info(buf);    //将 ArrayBufferView  转换成Blob    var buf = new Uint8Array(reader.result);    console.info(buf); //[228, 184, 173, 230, 150, 135, 229, 173, 151, 231, 172, 166, 228, 184, 178]    reader.readAsText(new Blob([buf]), ‘utf-8‘);    reader.onload = function () {        console.info(reader.result); //中文字符串    };    //将 ArrayBufferView  转换成Blob    var buf = new DataView(reader.result);    console.info(buf); //DataView {}    reader.readAsText(new Blob([buf]), ‘utf-8‘);    reader.onload = function () {        console.info(reader.result); //中文字符串    };}

关于Blob对象,请参考:http://www.cnblogs.com/tianma3798/p/4293660.html

HTML5 Blob与ArrayBuffer、TypeArray和字符串String之间转换