java - 从 assets 文件夹中读取 pdf 文件

Question

public void DOCS(View btnDocs)
{   
    File fileBrochure = new File("android.resource://com.project.datastructure/assets/abc.pdf");
    if (!fileBrochure.exists())
    {
         CopyAssetsbrochure();
    } 

    /** PDF reader code */
    File file = new File("android.resource://com.project.datastructure/assets/abc.pdf");        

    Intent intent = new Intent(Intent.ACTION_VIEW);
    intent.setDataAndType(Uri.fromFile(file),"application/pdf");
    intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    try 
    {
        getApplicationContext().startActivity(intent);
    } 
    catch (ActivityNotFoundException e) 
    {
         Toast.makeText(Stack_dr.this, "NO Pdf Viewer", Toast.LENGTH_SHORT).show();
    }
}
private void CopyAssetsbrochure() {
    AssetManager assetManager = getAssets();
    String[] files = null;
    try 
    {
        files = assetManager.list("");
    } 
    catch (IOException e){}
    for(int i=0; i<files.length; i++)
    {
        String fStr = files[i];
        if(fStr.equalsIgnoreCase("abc.pdf"))
        {
            InputStream in = null;
            OutputStream out = null;
            try 
            {
              in = assetManager.open(files[i]);
              out = new FileOutputStream("/sdcard/" + files[i]);
              copyFile(in, out);
              in.close();
              in = null;
              out.flush();
              out.close();
              out = null;
              break;
            } 
            catch(Exception e){}
        }
    }
}

 private void copyFile(InputStream in, OutputStream out) throws IOException 
  {
    byte[] buffer = new byte[1024];
    int read;
    while((read = in.read(buffer)) != -1){
      out.write(buffer, 0, read);
    }
}

我正在尝试从我的应用程序文件夹中的 assets 文件夹中读取一个 pdf 文件。当我点击我的 DOCS 按钮时，一切正常，弹出一个让我选择打开 pdf 的应用程序，即“abc.pdf”，但在选择一个选项后，我收到一条错误消息“文件路径无效”。我认为它们与我在代码中指定的路径存在一些问题。 请帮忙

Answer 1

试试这个

public class SampleActivity extends Activity
    {

        @Override
        protected void onCreate(Bundle savedInstanceState)
        {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);
            CopyReadAssets();

        }

        private void CopyReadAssets()
        {
            AssetManager assetManager = getAssets();

            InputStream in = null;
            OutputStream out = null;
            File file = new File(getFilesDir(), "abc.pdf");
            try
            {
                in = assetManager.open("abc.pdf");
                out = openFileOutput(file.getName(), Context.MODE_WORLD_READABLE);

                copyFile(in, out);
                in.close();
                in = null;
                out.flush();
                out.close();
                out = null;
            } catch (Exception e)
            {
                Log.e("tag", e.getMessage());
            }

            Intent intent = new Intent(Intent.ACTION_VIEW);
            intent.setDataAndType(
                    Uri.parse("file://" + getFilesDir() + "/abc.pdf"),
                    "application/pdf");

            startActivity(intent);
        }

        private void copyFile(InputStream in, OutputStream out) throws IOException
        {
            byte[] buffer = new byte[1024];
            int read;
            while ((read = in.read(buffer)) != -1)
            {
                out.write(buffer, 0, read);
            }
        }

    }

确保包含

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

在 list 中