如何在 asynctask 上显示加载动画 在PostExecute方法上

Question

我需要在我的 Android 项目上显示加载动画，等待响应即将到来。 我尝试显示加载消息。 我需要在响应到来后隐藏。

private void searchCustomer(final String username, final String 
                             password, final String baseUrl, final ProgressDialog dialog) {
    AsyncTask<String, String, String> checkLogin = new AsyncTask<String, String, String>() {
    final ProgressDialog dialog = new ProgressDialog(MainActivity.this);
    @Override
    protected String doInBackground(String... strings) {
        MediaType mediaType = MediaType.parse("application/json");
        RequestBody body = RequestBody.create(mediaType, "{nt"custUserName": ""+ username +"",nt"custPassword": ""+ password +""n}");
        Request request = new Request.Builder()
                .url(baseUrl + "customerLogin")
                .post(body)
                .addHeader("Content-Type", "application/json")
                .build();
        try {
            Response response = okHttpClient.newCall(request).execute();
            return response.body().string();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "";
    }
    @Override
    protected void onPostExecute(String s) {
        dialog.setMessage("Processing...");
        dialog.show();
        StringBuilder sb = new StringBuilder();
        char[] temp = s.toCharArray();
         for (char current : temp) {
         if (current != '"') {
             sb.append(current);
            }
        }
        String s1 = sb.toString();
        if (s1.equals("true")) {
        Notification.showSuccessMdToast("Login Successful", getApplicationContext());
        Intent customerNav = new Intent(MainActivity.this, CustomerNav.class);
        startActivity(customerNav);
        }
    }
};
checkLogin.execute();

}

在帖子中执行响应值为真。 但处理对话框未隐藏。

Answer 1

工作

完成时调用doInBackground onPostExecute回调。

您必须在onPreExecute()内调用dialog.show();并将其隐藏在onPostExecute()上。 见下文：

AsyncTask<String, String, String> checkLogin = new AsyncTask<String, String, String>() {
final ProgressDialog dialog = new ProgressDialog(MainActivity.this);
 @Override
 protected void onPreExecute() {
     super.onPreExecute();
     dialog.setMessage("Processing...");
     dialog.show();
 }
@Override
protected String doInBackground(String... strings) {
    MediaType mediaType = MediaType.parse("application/json");
    RequestBody body = RequestBody.create(mediaType, "{nt"custUserName": ""+ username +"",nt"custPassword": ""+ password +""n}");
    Request request = new Request.Builder()
            .url(baseUrl + "customerLogin")
            .post(body)
            .addHeader("Content-Type", "application/json")
            .build();
    try {
        Response response = okHttpClient.newCall(request).execute();
        return response.body().string();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return "";
}
@Override
protected void onPostExecute(String s) {
    dialog.dismis();
    StringBuilder sb = new StringBuilder();
    char[] temp = s.toCharArray();
     for (char current : temp) {
     if (current != '"') {
         sb.append(current);
        }
    }
    String s1 = sb.toString();
    if (s1.equals("true")) {
    Notification.showSuccessMdToast("Login Successful", getApplicationContext());
    Intent customerNav = new Intent(MainActivity.this, CustomerNav.class);
    startActivity(customerNav);
    }
}
};
checkLogin.execute();

Answer 2

您需要

隐藏if语句中的对话框，如下所示：

if (s1.equals("true") {
    dialog.dimiss();
}

附加提示：您可以在onPreExecute()中显示进度对话框，而不是以onPostExecute()显示