如何在创建PDF文件期间单击按钮时显示进度条，并在创建文件后隐藏它？
public class TwoFragment extends android.support.v4.app.Fragment {
private View v;
Intent chooser=null;
String myInt="";
String ciao="";
private String string="";
private ProgressBar pdfProgress;
ProgressTask task;
public TwoFragment() {
// Required empty public constructor
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View rootView = inflater.inflate(R.layout.fragment_two, container, false);
Button mButton = (Button) rootView.findViewById(R.id.newbutton);
mButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
//sendemail();
// pdfProgress.setVisibility(View.GONE);
/* pdfProgress.setVisibility(View.VISIBLE);
createPDF();
pdfProgress.setVisibility(View.GONE);
viewPDF();*/
/*MyAsyncTask myTask = new MyAsyncTask();
myTask.execute();
*/
showProgress();
}
});
TextView titolo3 = (TextView)rootView.findViewById(R.id.result);
TextView titolo2 = (TextView)rootView.findViewById(R.id.result2);
TextView titolo4 = (TextView)rootView.findViewById(R.id.resultpizze);
pdfProgress = (ProgressBar)rootView.findViewById(R.id.progressbar);
pdfProgress.setVisibility(View.GONE);
//pdfProgress.setVisibility(View.INVISIBLE);
//TextView titolo = (TextView)rootView.findViewById(R.id.quantità3);
/* class MyAsyncTask extends AsyncTask<Void, Void, Void> {
@Override
protected Void doInBackground(Void... params) {
// This runs in new thread!!!
// Always run long operations in another thread, so GUI will never be blocked
createPDF();
return null;
}
@Override
protected void onPostExecute(Void v) {
// This runs in MAIN thread, after the job's done.
// You always have to update gui from main thread
pdfProgress.setVisibility(View.GONE);
viewPDF();
}
}
*/
Bundle bundle2=getArguments();
if(bundle2 != null){
string = bundle2.getString("scelta2");
titolo3.setText(string);
}
/* Bundle bundle2=getArguments();
if(bundle2 != null){
// myInt = bundle2.getString("scelta2",myInt);
cacca=bundle2.getString("result",null);
//cacca=myInt;
// Log.d("ciao",cacca);
titolo3.setText(cacca);
}*/
//titolo3.setText(myInt);
/* Bundle bundle3=getArguments();
if(bundle3 != null){
// String myInt3 = bundle3.getString("totalebirre", null);
// cazzo2=Integer.parseInt(myInt3);
int cazzo2=bundle3.getInt("totalebirre");
titolo2.setText(String.valueOf(cazzo2));
}
Bundle bundle=getArguments();
if(bundle != null){
// String myInt2 = bundle2.getString("totalepizze", null);
// cazzo=Integer.parseInt(myInt2);
//titolo2.setText(myInt2);
String string=bundle.getString("scelta3", null);
titolo4.setText(string);
}
*/
return rootView;
}
/* public void sendemail(){
Intent intent = new Intent(Intent.ACTION_SEND);
intent.setData(Uri.parse("mailto:"));
String[] to={"marco_marcoletto@hotmail.it"};
intent.putExtra(Intent.EXTRA_EMAIL,to);
intent.putExtra(Intent.EXTRA_SUBJECT, "ciao");
intent.putExtra(Intent.EXTRA_TEXT, "zao");
intent.setType("message/rfc822");
chooser=intent.createChooser(intent,"manda email");
startActivity(chooser);
}*/
//@TargetApi(Build.VERSION_CODES.M)
public void createPDF() {
Document doc = new Document();
try {
String path = Environment.getExternalStorageDirectory()
.getAbsolutePath() + "/droidText";
File dir = new File(path);
if (!dir.exists())
dir.mkdirs();
Log.d("PDFCreator", "PDF Path: " + path);
//File file = new File(dir, "sample.pdf");
File file = new File(dir, "salve.pdf");
FileOutputStream fOut = new FileOutputStream(file);
PdfWriter.getInstance(doc, fOut);
// open the document
doc.open();
ByteArrayOutputStream stream = new ByteArrayOutputStream();
Bitmap bitmap = BitmapFactory.decodeResource(getContext()
.getResources(), R.drawable.androtuto);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
Image myImg = Image.getInstance(stream.toByteArray());
myImg.setAlignment(Image.MIDDLE);
// add image to document
doc.add(myImg);
Paragraph p1 = new Paragraph(string);
Font paraFont = new Font(Font.COURIER);
p1.setAlignment(Paragraph.ALIGN_CENTER);
p1.setFont(paraFont);
// add paragraph to document
doc.add(p1);
Paragraph p2 = new Paragraph("Bonjour Android Tuto");
Font paraFont2 = new Font(Font.COURIER, 14.0f, Color.GREEN);
p2.setAlignment(Paragraph.ALIGN_CENTER);
p2.setFont(paraFont2);
doc.add(p2);
stream = new ByteArrayOutputStream();
bitmap = BitmapFactory.decodeResource(getContext()
.getResources(), R.drawable.android);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
myImg = Image.getInstance(stream.toByteArray());
myImg.setAlignment(Image.MIDDLE);
// add image to document
doc.add(myImg);
// set footer
Phrase footerText = new Phrase("Pied de page ");
HeaderFooter pdfFooter = new HeaderFooter(footerText, false);
doc.setFooter(pdfFooter);
} catch (DocumentException de) {
// Log.e("PDFCreator", "DocumentException:" + de);
Log.e("PDFCreator", "DocumentException:" + de.getMessage());
} catch (IOException e) {
// Log.e("PDFCreator", "ioException:" + e);
Log.e("PDFCreator", "DocumentException:" + e.getMessage());
} finally {
doc.close();
}
}
public void viewPDF(){
String path = "/sdcard/droidText/salve.pdf";
File targetFile = new File(path);
Uri targetUri = Uri.fromFile(targetFile);
Intent intent;
intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(targetUri, "application/pdf");
startActivity(intent);
}
private class ProgressTask extends AsyncTask<Integer,Integer,Void> {
protected void onPreExecute() {
pdfProgress.setMax(100); // set maximum progress to 100.
}
protected void onCancelled() {
pdfProgress.setMax(0); // stop the progress
}
protected Void doInBackground(Integer... params) {
int start=params[0];
for(int i=start;i<=100;i+=5){
try {
boolean cancelled=isCancelled();
if(!cancelled) {
publishProgress(i);
Log.v("Progress","increment " + i);
//onProgressUpdate(i);
SystemClock.sleep(1000);
}
createPDF();
} catch (Exception e) {
Log.e("Error", e.toString());
}
}
return null;
}
protected void onProgressUpdate(Integer... values) {
// increment progress bar by progress value
//setProgress(10);
}
protected void onPostExecute(Void result) {
// async task finished
Log.v("Progress", "Finished");
viewPDF();
}
}
public void showProgress() {
task = new ProgressTask();
// start progress bar with initial progress 10
///////////////////task.execute(10,10,null);
task.execute(10);
}
}
答案 0 :(得分：2)
在片段中定义ProgressDialog，如下所示。以下代码将添加ProgessDialog;要更新它以显示进度条，请阅读this。
private ProgressDialog processingDialog;
现在，在onClick()
mButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
processingDialog = ProgressDialog.show(this, "Creating PDF", "Please wait ...", true, false);
createPDF();
processingDialog.dismiss();
viewPDF();
}
});
这应该可以完成任务，但是，我还有一些建议。由于创建PDF（我假设）将非常耗时，因此在UI线程上执行此操作可能不是一个好主意。相反，使用AsyncTask在doInBackground()中生成PDF，在ProgressDialog中显示dismiss()，最后onPostExecute()。
答案 1 :(得分：0)
此代码将使用AsyncTask执行您想要的操作，这是建议的方式！
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
调用AsyncTasknew MakePDF(ActivityName.this).execute(); //here in constructor pass context of an calling activity.
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