FileReader: readAsBinaryString() method
The readAsBinaryString
method is used to start reading the contents of the
specified Blob
or File
. When the read operation is
finished, the readyState
becomes
DONE
, and the FileReader.loadend_event
is triggered. At that time, the
result
attribute contains the raw binary data from
the file.
Note that this method was once removed from the File API specification, but
re-introduced for backward compatibility.
Using FileReader.readAsArrayBuffer()
is recommended.
Syntax
js
readAsBinaryString(blob)
Parameters
Return value
None (undefined
).
Examples
js
const canvas = document.createElement("canvas");
const height = 200;
const width = 200;
canvas.width = width;
canvas.height = height;
const ctx = canvas.getContext("2d");
ctx.strokeStyle = "#090";
ctx.beginPath();
ctx.arc(width / 2, height / 2, width / 2 - width / 10, 0, Math.PI * 2);
ctx.stroke();
canvas.toBlob((blob) => {
const reader = new FileReader();
reader.onload = () => {
console.log(reader.result);
};
reader.readAsBinaryString(blob);
});
Specifications
Specification |
---|
File API # readAsBinaryString |
Browser compatibility
BCD tables only load in the browser