只读。此视图的从其 ArrayBuffer 开始的偏移量（以字节为单位）在构造时已固定。 ## 语法 ~~~ var arrayOffset = dataView.byteOffset; ~~~ 下面的示例演示如何获取 DataView 的长度。 ~~~ var req = new XMLHttpRequest(); req.open('GET', "http://www.example.com"); req.responseType = "arraybuffer"; req.send(); req.onreadystatechange = function () { if (req.readyState === 4) { var buffer = req.response; var dataView = new DataView(buffer); alert(dataView.byteOffset) } } ~~~