1.將String字符串轉(zhuǎn)換成Blob對象1.將String字符串轉(zhuǎn)換成Blob對象//將字符串 轉(zhuǎn)換成 Blob 對象 var blob = new Blob(["Hello World!"], { type: 'text/plain' }); console.info(blob); console.info(blob.slice(1, 3, 'text/plain')); 2.將TypeArray 轉(zhuǎn)換成 Blob 對象 //將 TypeArray 轉(zhuǎn)換成 Blob 對象 var array = new Uint16Array([97, 32, 72, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100, 33]); //測試成功 //var blob = new Blob([array], { type: "application/octet-binary" }); //測試成功, 注意必須[]的包裹 var blob = new Blob([array]); //將 Blob對象 讀成字符串 var reader = new FileReader(); reader.readAsText(blob, 'utf-8'); reader.onload = function (e) { console.info(reader.result); //a Hello world! } ArrayBuffer轉(zhuǎn)Blob
var buffer = new ArrayBuffer(32); var blob = new Blob([buffer]); // 注意必須包裹[]
3,將Blob對象轉(zhuǎn)換成String字符串,使用FileReader的readAsText方法 //將字符串轉(zhuǎn)換成 Blob對象 var blob = new Blob(['中文字符串'], { type: 'text/plain' }); //將Blob 對象轉(zhuǎn)換成字符串 var reader = new FileReader(); reader.readAsText(blob, 'utf-8'); reader.onload = function (e) { console.info(reader.result); } 4.將Blob對象轉(zhuǎn)換成ArrayBuffer,使用FileReader的 readAsArrayBuffer方法 //將字符串轉(zhuǎn)換成 Blob對象 var blob = new Blob(['中文字符串'], { type: 'text/plain' }); //將Blob 對象轉(zhuǎn)換成 ArrayBuffer var reader = new FileReader(); reader.readAsArrayBuffer(blob); reader.onload = function (e) { console.info(reader.result); //ArrayBuffer {} //經(jīng)常會遇到的異常 Uncaught RangeError: byte length of Int16Array should be a multiple of 2 //var buf = new int16array(reader.result); //console.info(buf); //將 ArrayBufferView 轉(zhuǎn)換成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 }; //將 ArrayBufferView 轉(zhuǎn)換成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 }; } 關(guān)于Blob對象,請參考:http://www.cnblogs.com/tianma3798/p/4293660.html |
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