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FileReader.readAsDataURL()

The readAsDataURL method is used to read the contents of the specified or . When the read operation is finished, the becomes DONE, and the loadend is triggered. At that time, the attribute contains the data as a representing the file’s data as a base64 encoded string.

Note: The blob’s cannot be directly decoded as Base64 without first removing the Data-URL declaration preceding the Base64-encoded data. To retrieve only the Base64 encoded string, first remove data:*/*;base64, from the result.

instanceOfFileReader.readAsDataURL(blob);

• blob

  The or from which to read.

选择、读取单个文件并预览

选择、读取多个文件并预览

参考