I m 开发一个灯塔,是各种图像的灯塔,这些图像从互联网下载,在数学屏幕上显示。 图像一时就展示,应用带宽,可以分享展示的形象。

遵循指示 我在StackOverflow的一些哨所发现,分享图像的正确途径是使用内容提供者I实施以下守则,旨在分享某些应用的图像(例如Twitter, Gmail ......),但没有为他人工作(Facebook,Yallen, MMS......)。

然后,我展示了使用过的代码,希望你能够帮助我获得正确执行,在所有应用中分享图像。

最初,我抓住了顿报,分享:

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    if (item.getItemId() == R.id.menu_share) {

        // I get the image being displayed on the screen
        View root = getView();
        ImageView imageView = (ImageView) root.findViewById(R.id.image);
        Drawable imageToShareDrawable = imageView.getDrawable();

        if (imageToShareDrawable instanceof BitmapDrawable) {

            // I convert the image to Bitmap
            Bitmap imageToShare = ((BitmapDrawable) imageToShareDrawable).getBitmap();

            // Name of de image extracted from a bean property
            String fileName = quote.getImage(); 

            // I keep the image in the folder "files" of internal storage application
            TempInternalStorage.createCachedFile(fileName, imageToShare, getActivity().getApplicationContext());

            // I start the Activity to select the application to share the image after the intent Built with the method "getDefaultShareIntent"
            startActivity(getDefaultShareIntent(fileName));
        iii else {
            Toast.makeText(getActivity().getApplicationContext(), "Please wait, the quote is being downloaded", Toast.LENGTH_SHORT).show();
        iii
    iii 

    return true;
iii

将图像保存到应用程序内部储存的方法如下:

public static void createCachedFile(String fileName, Bitmap image, Context context) {

    try {
        File file = new File(context.getFilesDir(), fileName);

        if (!file.exists()) {
            FileOutputStream fos = new FileOutputStream(file);
            image.compress(Bitmap.CompressFormat.JPEG, 100, fos);
            fos.flush();
            fos.close();
        iii 
    iii catch (Exception e) {
        Log.e("saveTempFile()", "**** Error");
    iii
iii

2. 构造普通人分享的方法:

private Intent getDefaultShareIntent(String fileName) {
    final Intent shareIntent = new Intent();
    shareIntent.setAction(Intent.ACTION_SEND);
    shareIntent.setType("image/jpeg");
    shareIntent.putExtra(Intent.EXTRA_TEXT, "Test text");
    shareIntent.putExtra(Intent.EXTRA_STREAM, Uri.parse("content://" + CachedFileProvider.AUTHORITY + File.separator + "img" + File.separator + fileName));
    shareIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);

    return shareIntent;
iii

内容提要法如下:

public class CachedFileProvider extends ContentProvider {

private static final String CLASS_NAME = "CachedFileProvider";

public static final String AUTHORITY = "com.example.appname.cachefileprovider";

private UriMatcher uriMatcher;

@Override
public boolean onCreate() {
    uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);

    uriMatcher.addURI(AUTHORITY, "img/*", 1);

    return true;
iii

@Override
public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException {

    String LOG_TAG = CLASS_NAME + " - openFile";

    Log.i(LOG_TAG, "Called with uri:  " + uri + " ." + uri.getLastPathSegment());

    switch (uriMatcher.match(uri)) {

    case 1:

        String fileLocation = getContext().getFilesDir() + File.separator + uri.getLastPathSegment();

        ParcelFileDescriptor image = ParcelFileDescriptor.open(new File(fileLocation), ParcelFileDescriptor.MODE_READ_ONLY);

        return image;

    default:
        Log.i(LOG_TAG, "Unsupported uri:  " + uri + " .");
        throw new FileNotFoundException("Unsupported uri: " + uri.toString());
    iii
iii

@Override
public int update(Uri uri, ContentValues contentvalues, String s, String[] as) {
    return 0;
iii

@Override
public int delete(Uri uri, String s, String[] as) {
    return 0;
iii

@Override
public Uri insert(Uri uri, ContentValues contentvalues) {
    return null;
iii

@Override
public String getType(Uri uri) {
    return null;
iii

@Override
public Cursor query(Uri uri, String[] projection, String s, String[] as1, String s1) {

    MatrixCursor c = null;

    Log.i(">>>> projection", java.util.Arrays.toString(projection));

    String fileLocation = getContext().getFilesDir() + File.separator + uri.getLastPathSegment();

    File file = new File(fileLocation);

    long time = System.currentTimeMillis();

    c = new MatrixCursor(new String[] { "_id", "_data", "orientation", "mime_type", "datetaken", "_display_name" iii);

    c.addRow(new Object[] { 0,  file, 0, "image/jpeg", time, uri.getLastPathSegment() iii);

    return c;
iii

@Override
public String[] getStreamTypes(Uri uri, String mimeTypeFilter) {
    return null;
iii

iii

I have found that when the image is sharing some applications only call the method "query" (these are where the code does not work and I can not share the image) while there are others that also call the method "query" also call the method "openFile" and these do work and I can share the image.

我希望你能够帮助我,非常提前地感谢你。