var blob = this .file.slice( this .readed, this .readed + this .step);
this .reader.readAsArrayBuffer(blob);
Solution:
When the reader reads, first judge the readyState value, and then execute the reading if it is not loading.
if (this.reader.readyState == 1)
return ;
var blob = this .file.slice( this .readed, this .readed + this .step);
this .reader.readAsArrayBuffer(blob);
readyState FileReader
| value | condition | describe |
|---|---|---|
0 |
EMPTY |
Reader has been created. No read methods have been called yet. |
1 |
LOADING |
The read method has been called. |
2 |
DONE |
The operation is complete. |
EMPTY- Created, but the readAs method has not yet been called .
FileReader LOADING- The readAs method is called. An or is being read , but an error has not yet occurred.
FileBlob DONE- The read operation is complete. This could mean: the whole or was read into memory, a file read error occurred, or the read was canceled when called.
FileBlobabort()
var reader = new FileReader();
console.log( 'EMPTY', reader.readyState); // readyState will be 0
reader.readAsText(blob);
console.log( 'LOADING', reader.readyState); // readyState will be 1
reader.onloadend = function () {
console.log( 'DONE', reader.readyState); // readyState will be 2
};