HTML5 FileReader interface learning notes, html5filereader

HTML5 FileReader interface learning notes, html5filereader

1. Overview of FileReader

FileReaderObjects allow Web applications to asynchronously read the content of files (or raw data buffers) stored on users' computers.FileOrBlobObject specifies the file or data to be read.

The File object can be<Input>Element returned after selecting a fileFileListObject, which can also be generated by the drag-and-drop operationDataTransferObject can also be fromHTMLCanvasElementRun onReturns the result after the mozGetAsFile () method is used..

2. FileReader Interface Method

Method Name	Parameters	Description
ReadAsBinaryString	File	Read the file as a binary code
ReadAsText	File, [encoding]	Read a file as text
ReadAsDataURL	File	Read the file as DataURL
ReadAsArrayBuffer	File	Read the fileArrayBuffer object
Abort	(None)	Interrupted read Operations

 

 

 

 

 

 

3. FileReader interface event

Event	Description
Onabort	Triggered when Data Reading is interrupted
Onerror	Triggered when a data read error occurs.
Onloadstart	Triggered when Data Reading starts.
Onprogress	Reading data
Onload	Triggered when Data Reading is completed successfully.
Onloadend	Triggered when Data Reading is complete, no matter whether the operation fails

 

 

 

 

 

 

 

4. Use instances

<! DOCTYPE html> 
For more information, see MDN FileReader.