Question

我在

的app的内部存储空间中有一个 abc.pdf 文件

 data/data/com.example.p10documentapp/app_this_app_dir/abc.pdf

我首先将文件复制到catch目录

 /data/data/com.example.p10documentapp/cache/data/data/com.example.p10documentapp/app_this_app_dir/ferguson_book.pdf

然后我尝试使用 Intent.ACTION_VIEW

打开abc.pdf

我可以在ServiceProvider类的openFile（）方法中打开文件。但该文件未通过pdf阅读器开放。请告诉我我做错了什么

MyActivity.class

void startInternt(){
  copyFileToInternal("abc.pdf");
  Intent intent = new Intent();
  File file = new File(activity.getCacheDir(), directory + "/" +  item.getName());
  Uri uri = FileProvider.getUriForFile( activity,   "com.example.p10documentapp", file);
  intent.setAction(Intent.ACTION_VIEW);
  intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
  intent.setDataAndType(uri, "application/pdf");
  try {
       activity.startActivity(intent);
  }
  catch (ActivityNotFoundException e) {
       e.printStackTrace();
  }
}

  private void copyFileToInternal(String name) {
    try {
        InputStream is = new FileInputStream(directory + "/" + name);
        File cacheDir = activity.getCacheDir();
        File outFile = new File(cacheDir.getAbsolutePath(), name);

        OutputStream os = new FileOutputStream(outFile);

        byte[] buff = new byte[1024];
        int len;
        while ((len = is.read(buff)) > 0) {
            os.write(buff, 0, len);
        }
        os.flush();
        os.close();
        is.close();

    } catch (IOException e) {
        e.printStackTrace(); // TODO: should close streams properly here
    }
}

ServiceProvider.java类

public class ServiceProvider extends ContentProvider {
static final String PROVIDER_NAME = "com.example.p10documentapp";
static final String URL = "content://" + PROVIDER_NAME + "/this_app_dir";
static final Uri CONTENT_URI = Uri.parse(URL);
private static final String PDFPATH = "public_pdfs/";

private final static String[] COLUMNS = {OpenableColumns.DISPLAY_NAME, OpenableColumns.SIZE};

static final String name = "name";
static final int uriCode = 1;
static final UriMatcher uriMatcher;

static {
    uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
    uriMatcher.addURI(PROVIDER_NAME, "this_app_dir", uriCode);
    uriMatcher.addURI(PROVIDER_NAME, "this_app_dir/*", uriCode);
}

@Nullable
@Override
public ParcelFileDescriptor openFile(@NonNull Uri uri, @NonNull String mode) throws FileNotFoundException {
    File cacheDir = getContext().getCacheDir();
    File file = new File(cacheDir,uri.getPath());
    return ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_ONLY);
}

  @Override
public boolean onCreate() {
    return true;
}

@Nullable
@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
    return null;
}

@Nullable
@Override
public String getType(Uri uri) {
    return "application/pdf";
}

@Nullable
@Override
public Uri insert(Uri uri, ContentValues values) {
    return null;
}

@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
    return 0;
}

@Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
    return 1;
}

}

AndroidManifest.xlm

  <provider
        android:name=".ServiceProvider"
        android:authorities="com.example.p10documentapp"
        android:exported="false"
        android:grantUriPermissions="true"
        >
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/filepaths" />

    </provider>

filepaths.xml文件

    <paths xmlns:android="http://schemas.android.com/apk/res/android">
         <cache-path name="this_app_dir" path="." />
    </paths>

如何使用内容提供商

0 个答案: