Question

点击按钮后，我想显示alertDialog，显示animationDrawable并执行asyncTask。我发现当我将context的{{1}}设置为getApplicationContext（）时，应用程序崩溃了，当我将上下文设置为父类dialog时，activity当我在活动类中调用dismiss方法时，我被很好地解雇了;但是当我想在AsyncTask的onPostExecute中解除它时，对话框不会被解雇！这是代码：

dialog

那么如何使用上下文？

Answer 1

设置Context in Constructor of AsyncTask＆amp;传递AsyncTask调用的上下文。

Show your Dialogue in onPreExecute() AsyncTask

Cancel您的对话onPostExecute()。

 private class RunInBackground extends AsyncTask<Void, Void, Void> {

    private ProgressDialog dialog;
    private Context contextInsideDialogue;

    public RunInBackground(Context activity) {
        try {

            this.contextInsideDialogue = activity;

            dialog = new ProgressDialog(activity,
                    android.R.style.Theme_DeviceDefault_Light_Panel);
            dialog.setCanceledOnTouchOutside(false);
            dialog.setCancelable(false);
            dialog.getWindow().setGravity(Gravity.BOTTOM);

        } catch (Exception e) {
        }
    }

    @Override
    protected void onPreExecute() {
        try {
            dialog.setMessage("Please wait. . ");
            dialog.show();
        } catch (Exception e) {
        }

    }

@Override
    protected void onPostExecute(Void result) {
        try {
            if (dialog.isShowing()) {
                dialog.dismiss();

            }
        } catch (Exception e) {
        }
    }
 }

＆安培;将其调用为

  RunInBackground task = new RunInBackground (MyActivity.this);
  task.execute();

AsyncTask的上下文问题

1 个答案: