在文件创建过程中如何显示进度条？

此代码将使用推荐的AsyncTask来完成您想做的事情！

private class MakePDF extends AsyncTask<Void, Void, Void> {       private ProgressDialog processingDialog; Context cnt = null;MakePDF(Context cnt)      {   this.cnt = cnt;       }     @Override     protected void onPreExecute() {         super.onPreExecute();         processingDialog = ProgressDialog.show( this.cnt, "Creating PDF", "Please wait ...", true, false);     }     @Override     protected Void doInBackground(Void... arg0) {    createPDF();         return null;     }     @Override     protected void onPostExecute(Void aVoid) {         super.onPostExecute(aVoid);        processingDialog.dismiss();        viewPDF();         } }

现在使用以下命令在AsyncTask上方调用

new MakePDF(ActivityName.this).execute(); //here in constructor pass context of an calling activity.

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