FileReader to String

问题

Consider the following code

function readSingleFile(evt) {
            //Retrieve the first (and only!) File from the FileList object
            var myFile = evt.target.files[0];
            var reader = new FileReader();
            reader.readAsText(myFile);
            var myString = reader.toString();
            alert(myString); // print  - "[object FileReader]"
        }

I try to get all the file content into String , for example if the file content is

helloWorld1
helloWorld2

I will get alert of that's content .

回答1:

That's not how you get the result of a FileReader. Modify your code to this:

function readSingleFile(evt) {
        //Retrieve the first (and only!) File from the FileList object
        var myFile = evt.target.files[0];
        var reader = new FileReader();
        reader.readAsText(myFile);
        reader.onload=function(){alert(reader.result)}
    }

来源：https://stackoverflow.com/questions/21962032/filereader-to-string