java - Android编程，后台任务(Context)中的后台任务不能应用到()

Question

我需要一些帮助来解决这个问题，它以前有效，但在更改了几个代码后，这可能是一个问题。也许是因为我从 fragment 切换到 Activity 。

btnRegister.setOnClickListener(new android.view.View.OnClickListener() {
            @Override
            public void onClick(android.view.View v) {

                if (name.getText().toString().equals("") || email.getText().toString().equals("") || pw.getText().toString().equals("")) {


                    android.app.AlertDialog.Builder alertDialogBuilder =
                            new android.app.AlertDialog.Builder(Register.this);
                    alertDialogBuilder.setTitle("Something went wrong");
                    alertDialogBuilder.setMessage("Please check and fill in all the fields");
                    alertDialogBuilder.setPositiveButton("Ok", new android.content.DialogInterface.OnClickListener() {
                        public void onClick(android.content.DialogInterface dialog, int which) {
                            dialog.dismiss();
                        }
                    });
                    //displaying of alert dialog
                    android.app.AlertDialog alertDialog = alertDialogBuilder.create();
                    alertDialog.show();
                }
                //checking pw and confirm pw
                else if (!pw.getText().toString().equals(pwConf.getText().toString())) {

                    android.app.AlertDialog.Builder alertDialogBuilder =
                            new android.app.AlertDialog.Builder(Register.this);
                    alertDialogBuilder.setTitle("Something went wrong");
                    alertDialogBuilder.setMessage("Your passwords are not matching");
                    alertDialogBuilder.setPositiveButton("Ok", new android.content.DialogInterface.OnClickListener() {
                        public void onClick(android.content.DialogInterface dialog, int which) {
                            dialog.dismiss();
                            pw.setText("");
                            pwConf.setText("");
                        }
                    });
                    android.app.AlertDialog alertDialog = alertDialogBuilder.create();
                    alertDialog.show();
                }

                else{
                    BackgroundTask backgroundTask = new BackgroundTask();
                    backgroundTask.execute("register", name.getText().toString(), email.getText().toString(), pw.getText().toString());
                }
            }
        });

是的，因此在后台任务=新后台任务的设置中，它显示错误，指出“后台任务中的后台任务(上下文)无法应用于()。

这是我的后台任务类。

public class BackgroundTask extends android.os.AsyncTask<String, Void, String>{

    android.content.Context ctx;
    android.app.Activity activity;
    android.app.ProgressDialog progressDialog;
    String register_url = "http://10.0.2.2/mydb/register.php";
    android.app.AlertDialog.Builder builder;


    public BackgroundTask(android.content.Context ctx) {

        this.ctx = ctx;
        activity = (android.app.Activity)ctx;

    }

Answer 1

你的构造函数需要一个上下文。改变

BackgroundTask backgroundTask = new BackgroundTask();

至

BackgroundTask backgroundTask = new BackgroundTask(getActivity());