我正在处理PDF渲染,现在出现错误消息:“格式字符串不是有效格式”。到目前为止,我的代码是:
import android.app.Fragment;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.pdf.PdfRenderer;
import android.os.Bundle;
import android.os.ParcelFileDescriptor;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;
import java.io.IOException;
/**
*/
public class PDFRenderFragment extends android.support.v4.app.Fragment {
private ParcelFileDescriptor fileDescriptor;
private PdfRenderer pdfRenderer;
private PdfRenderer.Page currentPage;
private ImageView image;
private Button btnPrevious;
private Button btnNext;
public PDFRenderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_pdfrender, container, false);
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
// Retain view references.
image = (ImageView) view.findViewById(R.id.image);
btnPrevious = (Button) view.findViewById(R.id.btn_previous);
btnNext = (Button) view.findViewById(R.id.btn_next);
//set buttons event
btnPrevious.setOnClickListener(onActionListener(-1)); //previous button clicked
btnNext.setOnClickListener(onActionListener(1)); //next button clicked
int index = 0;
// If there is a savedInstanceState (screen orientations, etc.), we restore the page index.
if (null != savedInstanceState) {
index = savedInstanceState.getInt("current_page", 0);
}
showPage(index);
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
openRenderer(activity);
} catch (IOException e) {
e.printStackTrace();
Log.i("Fragment", "Error occurred!");
Log.e("Fragment", e.getMessage());
activity.finish();
}
}
@Override
public void onDestroy() {
try {
closeRenderer();
} catch (IOException e) {
e.printStackTrace();
}
super.onDestroy();
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
if (null != currentPage) {
outState.putInt("current_page", currentPage.getIndex());
}
}
/**
* Create a PDF renderer
* @param activity
* @throws IOException
*/
private void openRenderer(Activity activity) throws IOException {
// Reading a PDF file from the assets directory.
fileDescriptor = activity.getAssets().openFd("*****.pdf").getParcelFileDescriptor();
// This is the PdfRenderer we use to render the PDF.
pdfRenderer = new PdfRenderer(fileDescriptor);
}
/**
* Closes PdfRenderer and related resources.
*/
private void closeRenderer() throws IOException {
if (null != currentPage) {
currentPage.close();
}
pdfRenderer.close();
fileDescriptor.close();
}
/**
* Shows the specified page of PDF file to screen
* @param index The page index.
*/
private void showPage(int index) {
if (pdfRenderer.getPageCount() <= index) {
return;
}
// Make sure to close the current page before opening another one.
if (null != currentPage) {
currentPage.close();
}
//open a specific page in PDF file
currentPage = pdfRenderer.openPage(index);
// Important: the destination bitmap must be ARGB (not RGB).
Bitmap bitmap = Bitmap.createBitmap(currentPage.getWidth(), currentPage.getHeight(),
Bitmap.Config.ARGB_8888);
// Here, we render the page onto the Bitmap.
currentPage.render(bitmap, null, null, PdfRenderer.Page.RENDER_MODE_FOR_DISPLAY);
// showing bitmap to an imageview
image.setImageBitmap(bitmap);
updateUIData();
}
/**
* Updates the state of 2 control buttons in response to the current page index.
*/
private void updateUIData() {
int index = currentPage.getIndex();
int pageCount = pdfRenderer.getPageCount();
btnPrevious.setEnabled(0 != index);
btnNext.setEnabled(index + 1 < pageCount);
getActivity().setTitle(getString(R.string.app_name , index + 1, pageCount));
}
private View.OnClickListener onActionListener(final int i) {
return new View.OnClickListener() {
@Override
public void onClick(View v) {
if (i < 0) {//go to previous page
showPage(currentPage.getIndex() - 1);
} else {
showPage(currentPage.getIndex() + 1);
}
}
};
}
}
并在字符串文件中:
<string name="app_name">NewApp2</string>
如何解决错误消息。我从一点股票代码中拿走了所有这些,所以应该没有错误。设置了字符串名称后,确定可以从字符串启动活动了吗?如果有什么办法可以解决这个问题,请告诉我!
如果想同时显示index
,并pageCount
用app_name
在标题然后执行它:
1.将strings.xml文件中的字符串更改为:
<string name="app_name">NewApp2 %1$d / %2$d </string>
2.以以下方式访问代码中的格式化字符串:
String strTitle= getString(R.string.app_name , index + 1, pageCount);
getActivity().setTitle(strTitle);
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