```javascript
var NSData = plus.ios.importClass('NSData');
var nsData = new NSData();
var path = plus.io.convertLocalFileSystemURL('_doc/test.jpg');
//此处传入image的base64数据
nsData = nsData.initWithBase64EncodedStringoptions("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",0);
if (nsData) {
nsData.plusCallMethod({writeToFile:path,atomically:true});
plus.ios.deleteObject(nsData);
}
```

通过读取文件 ,然后转码 .图片可以,其他文件一样可以的
// Read data from file
以www目录下audio/shake.wav为例:
```javascript
plus.io.requestFileSystem(plus.io.PRIVATE_WWW,
function(fs) {
var rootEntry = fs.root;
var reader = null;
rootEntry.getFile('audio/shake.wav', {},
function(entry) {
entry.file(function(file) {
reader = new plus.io.FileReader();
reader.onloadend = function(e) {
plus.console.log("Read success");
// Get data
plus.console.log(e.target.result);
};
reader.readAsDataURL(file);
},
function(e) {
alert(e.message);
});
});

});
```