无法在线程中创建handler

Question

错误：

logUser("An error happend while creating graph:"+ getErrorMessage());

getErrorMessage()无法在线程中创建handler，线程没有调用Looper.prepare()，而logUser 是用来显示toast信息的函数。

void prepareGraph() {
    logUser("loading graph (" + Helper.VERSION + "|" + Helper.VERSION_FILE
            + ") ... ");
    new MyAsyncTask<Void, Void, Path>() {
        protected Path saveDoInBackground(Void... v) throws Exception {
            GraphHopper tmpHopp = new GraphHopper().forAndroid();
            tmpHopp.contractionHierarchies(true);
            tmpHopp.load(mapsFolder + currentArea);
            logUser("found graph with " + tmpHopp.getGraph().nodes() + " nodes");
            hopper = tmpHopp;
            return null;
        }
        protected void onPostExecute(Path o) {
            if (hasError()) {
                logUser("An error happend while creating graph:"
                        + getErrorMessage());
            } else {
                logUser("Finished loading graph. Touch to route.");
                calcPath(52.534185, 13.348732, 52.53857,
                        13.41259);
            }
            finishPrepare();
        }
    }.execute();
}

Answer 1

同上求解，请问你解决了吗？