Question

下面是我创建的异步类，我正在尝试在执行时实现对话框，并在完成时实现Toast。

无论如何都没有出现祝酒或对话。

我的asykTask：

public class EmailPictureService extends HTTPRequestAsyncTask {
    Context context;
    ProgressDialog dialog;
    public EmailPictureService(Context context){
        this.context = context;
        //dialog = new ProgressDialog(context);
    }
    @Override
    protected void onPreExecute() {

        super.onPreExecute();
    }   

    @Override
    protected String doInBackground(Object... params) {
        Log.v("Start EMAIL SERVICE","START YOPPPPPPPPPPPPPPPPPPPPPP!");
        dialog = new ProgressDialog(context);
        dialog.setMessage("Sending...");
        dialog.setIndeterminate(true);
        dialog.show();
        HTTPInvoker invoker = new HTTPInvoker();
        HttpResponse response = null;

        EmailPicture emailPicture = new EmailPicture();
        emailPicture.setDeviceType("TABLET");
        emailPicture.setStoreId((String)params[1]);
        emailPicture.setNotificationType("E");
        emailPicture.setRecipientName((String)params[2]);
        emailPicture.setRecipientEmail((String)params[3]);

        String jsonString = JSONConverter.toJson(emailPicture);
        response = invoker.invokePOSTFileService((String)params[0], jsonString, (File[])params[4]);
        return parseHttpResponse(response);
    }

    @Override
    protected void onPostExecute(String result) {
        String msg = "";
        if (dialog.isShowing()) {
            dialog.dismiss();
        }
        if (result != null) {
            JSONObject jsonObject = null;
            long errorCode = 0;
            try {
                jsonObject = new JSONObject((String) result);
                errorCode = jsonObject.getLong("errorCode");
                if(errorCode<1){
                    msg ="Success, your picture has been sent";
                }else{
                    msg = "Sorry, there was an error sending your picture. Please try again later.";
                }
                Log.i(Constants.TAG, "Error Code...." + errorCode);
                Toast toast = Toast.makeText(context, msg, Toast.LENGTH_SHORT);
                toast.show();

            } catch (JSONException e1) {
                Log.i(Constants.TAG, "Exception...." + e1);
                Toast toast = Toast.makeText(context, "Failure: "+e1, Toast.LENGTH_SHORT);
                toast.show();
                e1.printStackTrace();
            }
        }

    }

}

我如何从我的活动中调用它：

new EmailPictureService(this).execute(url,storeID,cusName, cusEmail, new File[]{file});

我的日志 enter image description here

Answer 1

您不应尝试从doInBackground()访问用户界面。 AsyncTasks和doInBackground()的目的是避免阻碍UI线程...相反，您应该使用适当的方法预先形成UI工作：onPreExecute()，onProgressUpdate()，onPostExecute()，等

Answer 2

我怀疑吐司没有显示，因为你的结果总是为空。您的日志在帖子上显示错误

正如其他人所说，从onPreExecute（）

开始你的进度对话框

Answer 3

我注意到你在doInBackground（）中实例化了progressDialog。将其移至onPreExecute（）。 doInBackground（）只能用于非UI工作。 =）

这应该“解决”你的问题。

asyncTask中没有显示对话框和Toast

3 个答案: