PhoneGap readAsDataURL

问题:

I am writing my first Android app using PhoneGap, but I'm a little confused by the documentation for the FileReader. I need to take an image file and convert it to a Base64 string using the readAsDataURL() method. From their documentation:

function win(file) { var reader = new FileReader(); reader.onloadend = function(evt) {     console.log("read success");     console.log(evt.target.result); }; reader.readAsDataURL(file); }; var fail = function(evt) { console.log(error.code); }; entry.file(win, fail); 

I understand pretty much all of that except for the last line: entry.file(win, fail). Nowhere is entry defined, but I assume it is a FileEntry object. The problem is that I have not had much luck finding documentation on how to generate the FileEntry object, and at what point I pass in a file path.

回答1:

Ok, finally got this to work. Horrible documentation online! I'm posting my code in case others are having trouble:

window.resolveLocalFileSystemURI(filePath,     // success callback; generates the FileEntry object needed to convert to Base64 string     function (fileEntry) {         // convert to Base64 string         function win(file) {             var reader = new FileReader();             reader.onloadend = function (evt) {                 var obj = evt.target.result; // this is your Base64 string             };             reader.readAsDataURL(file);         };         var fail = function (evt) { };         fileEntry.file(win, fail);     },     // error callback     function () { } ); 

文章来源: PhoneGap readAsDataURL