asyncTask中的ProgressDialog setProgress和setMessage不起作用 [英] ProgressDialog setProgress and setMessage inside asyncTask don't work

问题描述

我有一个asynktask，它显示一个progressDialog并在doInBackground方法中更新它的值.方法代码:

I have asynktask that shows a progressDialog and update its value in doInBackground method. the methods code:

@Override
protected void onPreExecute() {
    progress = new ProgressDialog(cont);
    progress.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
    progress.setIndeterminate(true);
    progress.setTitle(cont.getResources().getString(R.string.pleaseWait));
    progress.setMessage(cont.getResources().getString(R.string.loadingImages));
    progress.show();
    super.onPreExecute();
}

@Override
protected String doInBackground(Void... arg0) {
    progress.setProgress(2);
    //do some work on the database and network
    progress.setProgress(25);
    //Do some extra work
    for(int i = 0; i < itemImagesList.size(); i++){
        publishProgress((int) ((i / (float) itemImagesList.size()) * 100));
        //Do somework
    }
}

@Override
protected void onProgressUpdate(Integer... prog) {
    progress.setProgress(prog[0]);
}

@Override
protected void onPostExecute(String result) {
    progress.dismiss();
    super.onPostExecute(result);
}

progressDialog值完全不变！如果我尝试使用以下方法设置对话框消息:

The progressDialog value doesn't change at all! and if I tried to set the dialog message using:

progress.setMessage("At item "+i);

如果我将其放在方法的中间会发生一些异常，但是在第一个中它可以正常工作！

some exception occurs if I put it in the middle of the method, but in the first it works fine!

怎么了?

推荐答案

您的问题与setIndeterminate(true);有关，如果要进行进度更新，则应将其设置为false(请参阅

Your issue is related to setIndeterminate(true); You should set it to false if you want to have progress update (take a look at Android setProgress doc), don't forget to also use setMax() to set progress max value to the desired one.

正如洛朗所说，您只能在UI线程上更改进度，因此您必须在onProgressUpdate中而不是在doInBackground

And as said Laurent you can change progress only on UI thread so you have to do it in onProgressUpdate and not in doInBackground

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