Javascript jQuery加载微调器未显示

我正在开发android应用程序，我试图在格式化html时显示加载微调器，但微调器没有显示，我不知道原因。
下面是代码：

$.mobile.loading('show');
    if (window.localStorage.getItem("UserTeams") != null && manual == false) {
        $(window.localStorage.getItem("UserTeams")).appendTo("#listTeams");
        $("#listTeams").listview("refresh").listview();           
    }
$.mobile.loading('hide');

---

知道为什么微调器没有显示吗？

尝试通过JavaSriptInterface使用本机函数来显示进度

JavaScriptInterface：

private final class JavaScriptInterface {

    public JavaScriptInterface() {
    }

    /* progressDialog is a field of Your Activity.
       JavaScriptInterface is internal class of Your Activity. */

    public void showDialog() {
        if (progressDialog != null) {
            if (!progressDialog.isShowing()) {
                progressDialog = ProgressDialog.show(this, "", getString(R.string.common_loading_upper));
            }
        }
    }

    public void hideDialog() {
        if (progressDialog != null) {
            progressDialog.dismiss();
        }  
    }
}

webView.addJavascriptInterface(new JavaScriptInterface(), "myinterface");

注册JavaScriptInterface：

private final class JavaScriptInterface {

    public JavaScriptInterface() {
    }

    /* progressDialog is a field of Your Activity.
       JavaScriptInterface is internal class of Your Activity. */

    public void showDialog() {
        if (progressDialog != null) {
            if (!progressDialog.isShowing()) {
                progressDialog = ProgressDialog.show(this, "", getString(R.string.common_loading_upper));
            }
        }
    }

    public void hideDialog() {
        if (progressDialog != null) {
            progressDialog.dismiss();
        }  
    }
}

webView.addJavascriptInterface(new JavaScriptInterface(), "myinterface");

要调用对话框的JavaScript代码：

window.myinterface.showDialog();