在耗时操作的时候，出现一个
progressbar 让用等待一下 比白板好点
showProgressDialog();
private ProgressDialog progDialog = null;// 进度框
/**
* 显示进度框
*/
private void showProgressDialog() {
if (progDialog == null)
progDialog = new ProgressDialog(this);
progDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
progDialog.setIndeterminate(false);
progDialog.setCancelable(true);
progDialog.setMessage("正在搜索:\n");
progDialog.show();
}