如何在异步任务中使用进度对话框[duplicate]

Question

我想使用进度对话框与异步任务，我怎么能使用它。我试过了，但它在得到响应后向我显示对话框，这是我的调用函数。由于我预计我面临的问题是由于此应用程序响应 = reqClient.execute（.get（）;因为我还必须从此异步任务中获取返回值。因此，请参阅两个文件以进行折射

 void postHttpRequest(String userId,String pass,TextView error){
            RequestClient reqClient = new RequestClient(IweenTravelLoginPage.this);
            String AppResponse = null;
            try {
                url = "";
                Log.d("Http Post URL is ", url);
                AppResponse = reqClient.execute().get();

                String status = ValidateLoginStatus.checkLoginStatus(AppResponse);
                Log.d("Status recived", status);

                if(status.equals("200")){
                    saveInformation(userId,pass);
                    startingActivity();
                }else{
                    error.setText("Incorrect UserName or Password");
                }
            } catch (Exception e) {
                Log.e("Exception Occured", "Exception is "+e.getMessage());
            }

此功能用于发送请求

public class RequestClient extends AsyncTask<String, Void, String>{
    Context context;

    public RequestClient(Context c) {
        context = c;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected String doInBackground(String... aurl){
    String responseString="";
    HttpClient client = null;
    try {
         client = new DefaultHttpClient();  
         HttpGet get = new HttpGet(IweenTravelLoginPage.url);
         HttpResponse responseGet = client.execute(get);  
         HttpEntity resEntityGet = responseGet.getEntity();  
         if (resEntityGet != null) {  
             responseString = EntityUtils.toString(resEntityGet);
             Log.i("GET RESPONSE", responseString.trim());
         }
    } catch (Exception e) {
        Log.d("ANDRO_ASYNC_ERROR", "Error is "+e.toString());
    }
        Log.d("ANDRO_ASYNC_RESPONSE", responseString.trim());
        client.getConnectionManager().shutdown();
     return responseString.trim();

    }


    @Override
    protected void onPostExecute(String response) {
         super.onPostExecute(response); 
        }
}

因此，请建议我该怎么做才能显示流程对话框。我尝试了堆栈溢出上的所有示例。但这一切都不适合我。请帮忙

Answer 1

为此，您可以在asyncTask中使用onProgressUpdate（）。每次从doInBackground（）执行showProgressUpdate（）时都会调用它

Answer 2

在前面的答案的基础上，您可以通过修改listener函数来获取从Async任务返回的数据，该函数接受一个参数，该参数是返回数据

public interface OnTaskCompleted{
    void onTaskCompleted(String response);
}

然后在Async任务的postExecute函数中，让它使用返回数据调用侦听器

    @Override
    protected void onPostExecute(String response){
        //your stuff
        listener.onTaskCompleted(response);
    }

然后在调用Async任务的地方，您只需要实现侦听器。您可以让一个类实现侦听器或使用匿名类

OnTaskCompleted listener = new OnTaskCompleted() {
    void onTaskCompleted(String response){
        // We got return data from the Async Task, do stuff!
    }
};
RequestClient reqClient = new RequestClient(listener);
reqClient.execute();

为了显示进度对话框，您应该在调用异步任务之前将其设置为显示，然后一旦您收到来自Aysnc任务的回调，您就可以将其关闭。

//make progressDialog a member of your class
progressDialog = new ProgressDialog(IweenTravelLoginPage.this);
progressDialog.setMessage("Loading");
progressDialog.show();

OnTaskCompleted listener = new OnTaskCompleted() {
    void onTaskCompleted(String response){
        // get rid of the progress dialog
        progressDialog.dismiss;
        // We got return data from the Async Task, do stuff!
    }
};
RequestClient reqClient = new RequestClient(listener);
reqClient.execute();

Answer 3

你可以试试这个

extends AsyncTask<String, Void, String>{
Context context;

public RequestClient(Context c) {
    context = c;
}

@Override
protected void onPreExecute() {
    super.onPreExecute();
    progressDialog = new ProgressDialog(context);
    progressDialog.setMessage("Loading. Please Wait");
    progressDialog.setIndeterminate(false);
    progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
    progressDialog.setCancelable(true);
    progressDialog.show();
}

@Override
protected String doInBackground(String... aurl){
String responseString="";
HttpClient client = null;
try {
     client = new DefaultHttpClient();  
     HttpGet get = new HttpGet(IweenTravelLoginPage.url);
     HttpResponse responseGet = client.execute(get);  
     HttpEntity resEntityGet = responseGet.getEntity();  
     if (resEntityGet != null) {  
         responseString = EntityUtils.toString(resEntityGet);
         Log.i("GET RESPONSE", responseString.trim());
     }
} catch (Exception e) {
    Log.d("ANDRO_ASYNC_ERROR", "Error is "+e.toString());
}
    Log.d("ANDRO_ASYNC_RESPONSE", responseString.trim());
    client.getConnectionManager().shutdown();
 return responseString.trim();

}


@Override
protected void onPostExecute(String response) {
     super.onPostExecute(response); 
     progressDialog.dismiss();
        }
}