head.addEventListener('tap',function() {    var IMAGE_UNSPECIFIED = "image/*"; //相册显示的文件类型    var PHOTOZOOM = 2; // 获取完图片返回key    var PHOTOLAT = 1; // 剪裁完毕后返回key    var main = plus.android.runtimeMainActivity(); //h5+获取应用主Activity实例对象    var Intent = plus.android.importClass("android.content.Intent");    //导入java类intent对象  以下importClass都是使用安卓原生类    var MediaStore = plus.android.importClass("android.provider.MediaStore");    var File = plus.android.importClass("java.io.File");    var Uri = plus.android.importClass("android.net.Uri");    var intent = new Intent(Intent.ACTION_PICK, null);    intent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, IMAGE_UNSPECIFIED);    intent.putExtra("scale", true);    intent.putExtra("scaleUpIfNeeded", true);    var outPutPath = plus.io.convertLocalFileSystemURL("_www/head.jpg");    main.startActivityForResult(intent, PHOTOZOOM);    main.onActivityResult = function(requestCode, resultCode, data) {        if (PHOTOZOOM == requestCode) {            var file = new File(outPutPath);            // 输出目录uri            var outPutUri = Uri.fromFile(file);            if (data == undefined) {                return false;            }            plus.android.importClass(data);            var uri = data.getData();            var cropIntent = new Intent("com.android.camera.action.CROP"); //裁剪            cropIntent.setDataAndType(uri, IMAGE_UNSPECIFIED);            // 截图完毕后 输出目录            cropIntent.putExtra(MediaStore.EXTRA_OUTPUT, outPutUri);            cropIntent.putExtra("crop", "true");            //aspectX aspectY 是宽高的比例            cropIntent.putExtra("aspectX", 1);            cropIntent.putExtra("aspectY", 1);            // outputX outputY 是裁剪图片宽高            cropIntent.putExtra("outputX", 70);            cropIntent.putExtra("outputY", 70);            cropIntent.putExtra("return-data", true);            main.startActivityForResult(cropIntent, PHOTOLAT);        } else if (requestCode == PHOTOLAT) {            if (data == undefined) {                return false;            }            var a = new File(outPutPath);            if (!a.exists()) {                console.log(outPutPath);                mui.toast('裁剪错误');                return false;            }              img.src = outPutPath;        }    }});

参考文章 http://ask.dcloud.net.cn/question/8314