Question

我使用以下代码

创建了一个AsyncTask类

<div class="offerButtons">
  <button type="reset" class="btnReset"><span> No </span></button>
  <input type="text" class="offerInput" />
  <button type="submit" class="btnSubmit"><span> Yes </span></button>
</div>

我第一次尝试：我第一次看到ProgressDialog，但第二次打开活动时我什么都没得到。

我第二次尝试：即使是第一次尝试，我也没有得到ProgressDialog。

我在AsyncTask类中执行我的代码，代码：

public class removeDialog extends AsyncTask<Void, Void, Void> {

Context c;
ProgressDialog asyncDialog;
String page;

public removeDialog(Context c, String page) {
    this.c = c;
    this.page = page;

    asyncDialog = new ProgressDialog(c);
}

@Override
protected void onPreExecute() {
    //set message of the dialog
    asyncDialog.setTitle("Please wait");
    asyncDialog.setMessage("Loading...");
    asyncDialog.setCancelable(false);
    //show dialog
    asyncDialog.show();

    if (page == "algemeneVoorwaarden") {
        Intent intent = new Intent(c, algemeneVoorwaarden.class);
        c.startActivity(intent);
    }
    if (page == "contact") {
        Intent intent = new Intent(c, contactTest.class);
        c.startActivity(intent);
    }

    super.onPreExecute();
}

@Override
protected Void doInBackground(Void... arg0) {

    //don't touch dialog here it'll break the application
    //do some lengthy stuff like calling login webservice

    return null;
}

@Override
protected void onPostExecute(Void result) {
    //hide the dialog
    asyncDialog.dismiss();

    super.onPostExecute(result);
}
}

有人知道它为什么不起作用吗？请帮帮我。

Answer 1

您的对话框一旦显示就会被解除，因为您的doInBackground为空。尝试添加Thread.sleep()几秒钟，只是为了模拟延迟。

另外，我怀疑你开始的新活动会让对话落后。因此，我建议您暂时不使用这些新活动来测试代码。

public class RemoveDialog extends AsyncTask<Void, Void, Void> {

    ProgressDialog asyncDialog;

    public RemoveDialog(Context c) {
        asyncDialog = new ProgressDialog(c);
    }

    @Override
    protected void onPreExecute() {
        //set message of the dialog
        asyncDialog.setTitle("Please wait");
        asyncDialog.setMessage("Loading...");
        asyncDialog.setCancelable(false);

        //show dialog
        asyncDialog.show();

        super.onPreExecute();
    }

    @Override
    protected Void doInBackground(Void... arg0) {

        try {
            Thread.sleep(3000);
        }
        catch (InterruptedException ex) {
            ex.printStackTrace();
        }

        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        //hide the dialog
        asyncDialog.dismiss();

        super.onPostExecute(result);
    }
}

ProgressDialog新的Activity Asynctask没有显示，为什么？

1 个答案: