android - 屏幕锁定时关闭警告对话框

Question

当屏幕锁定和解锁时，我的警告对话框消失。在我的例子中，

1) 在 asynctask(内部类)中开始连接，这里的进度对话框开始说“请稍等...”。2) 连接完成后 ProgressDilog 被关闭并显示警告消息。

所以，在这个过程中，当我在连接启动时锁定屏幕时，不会显示警告消息，而是显示之前状态下的相同 Activity 。

alertBuilder = new AlertDialog.Builder(Registration.this);
alertBuilder.setMessage(Constants.TEXT_REGISTERED_SUCCESSFULLY);
alertBuilder.setCancelable(false);
alertBuilder.setPositiveButton(Constants.TEXT_OK, new android.content.DialogInterface.OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
    Util.saveData(Registration.this);
    Intent thanksYouIntent = new Intent(Registration.this,ThankYouActivity.class);
    Registration.this.finish();
} });
alertBuilder.create().show();

这是我提出对话框的代码。我听说要将对话框绑定(bind)到 Activity ，所以我尝试了 alertBuilder.create().setOwnerActivity(RegistrationActivity.this)。这也没有显示任何内容结果。

我不清楚的一件事是当父 Activity 暂停时正在运行 Connection 的内部 asyncTask 会发生什么。请任何人帮助我。

提前致谢，沙。

Answer 1

如果我错了请纠正我。根据我的观察，当 Activity 处于暂停状态时，相应的 AsyncTask 将停止。所以，在我的情况下，当屏幕被锁定时，asynctask 的 doInBackground 中的连接已经开始执行。但是由于屏幕锁定原因，asyncTask 已停止并且 onPostExecute 未成功完成。我在 onpostexecute 中的 alertDialog 未显示。所以，我'保存连接的响应状态并在屏幕上调用 oncreate 时显示它使用 bool 检查解锁。

下面是代码。代码量很大，但无法解释我的情况。

   private static boolean alertDialogDismissedUnExpectedly;
private static String _alertMessage; //alert Message is for saving the previous alert message displaying when screen is locked

protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  //coding part

  _registerImageView.setOnClickListener(new OnClickListener() {//here the asynctask starts running on click
    private String _response;
    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        _alertMessage = "";
        //post data for response
        String postcontent="Sucess";
        if(Constants.LOG)Log.d("Content to post is :", ""+postcontent);
        ResgiserAsyncTask asyncTask = new ResgiserAsyncTask(postcontent);
        asyncTask.execute(null);


   }
  if(alertDialogDismissedUnExpectedly && savedInstanceState != null){ // check for Alert Message dismissed unexpectedly

    if(_alertMessage == null ? true : _alertMessage.equalsIgnoreCase("")){ //intialise the last state of alert message if no alert message is set

        _alertMessage = _Engine.get_returnMessage();//this is my engine where parsing is done,So i'll get the previous response of connection

    }

    if(_alertMessage != null){
        if(_alertMessage.equalsIgnoreCase(Constants.TEXT_REGISTERED_SUCCESSFULLY) || _alertMessage.equalsIgnoreCase(Constants.TEXT_SUCCESS)){//my success case

            raiseSuccessDialog();//this is internal method

        }else{//failure case

            raiseDialog(_alertMessage);//this is internal method

        }
    }

  }else{

    alertDialogDismissedUnExpectedly = false;
    _alertMessage = "";
  }
}

private class ResgiserAsyncTask extends AsyncTask{
    private String _postContent;
    private Document _document;
    public ResgiserAsyncTask(String postContent) {
        // TODO Auto-generated constructor stub
        alertDialogDismissedUnExpectedly = true;//set the coolean to true and make it false Clicklistener of alertDialog
        _postContent= postContent;
    }
    @Override
    protected Void doInBackground(Void... arg0) {
        // TODO Auto-generated method stub
        _document = Util.postPage(Constants.URL_REGISTRATION, _postContent, true);
        return null;
    }
    @Override
    protected void onPostExecute(Void result) {
        // TODO Auto-generated method stub
        super.onPostExecute(result);
        if(_document != null){

            String _response = _Engine.parseRegistration(_document);
            if(!Constants.TEXT_SUCCESS.equalsIgnoreCase(_response)){
                raiseDialog(_response);
            }else{

                raiseSuccessDialog();
            }

        }
    }

}

private void raiseSuccessDialog(){

        _alertMessage = Constants.TEXT_REGISTERED_SUCCESSFULLY;
        alertBuilder = new AlertDialog.Builder(Registration.this);
        alertBuilder.setMessage(Constants.TEXT_REGISTERED_SUCCESSFULLY);
        alertBuilder.setCancelable(false);
        alertBuilder.setPositiveButton(Constants.TEXT_OK, new android.content.DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                // TODO Auto-generated method stub
                alertDialogDismissedUnExpectedly = false;
                Intent thanksYouIntent = new Intent(Registration.this,ThankYouActivity.class);
                startActivity(thanksYouIntent);
            }
        });
        alertBuilder.create().show();

}

private void raiseDialog(String message) {
        // TODO Auto-generated method stub
    _alertMessage  = message; // intialise the message to the raised dialog so that when screen is locked the alert can be displayed once again
    AlertDialog.Builder alertBuilder = new Builder(Registration.this);
        alertBuilder.setMessage(message);
        alertBuilder.setCancelable(false);
        alertBuilder.setPositiveButton(Constants.TEXT_OK, new android.content.DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                // TODO Auto-generated method stub
                alertDialogDismissedUnExpectedly = false;
            }
        });
        alertBuilder.create().show();

}

希望对遇到同样问题的人有所帮助。欢迎提出更好的想法。