java - 获取Android中所选图库图像的文件路径和文件名

Question

我正在创建一个应用程序，该应用程序从图库中上传选定的图像并将其上传到网络服务。 Web 服务需要所选图像的文件名以及文件内容的 base64 编码。我已经设法通过硬编码的文件路径来实现这一点。但是，我正在努力获取图像的真实文件路径。我已经在网上阅读并拥有此代码，但它对我不起作用:

 public void onActivityResult(int requestCode, int resultCode, Intent data) {
   if (resultCode == RESULT_OK) {
     Uri selectedImageUri = data.getData();
     String[] projection = {MediaStore.Images.Media.DATA};

     try {
       Cursor cursor = getContentResolver().query(selectedImageUri, projection, null, null, null);
       cursor.moveToFirst();

       int columnIndex = cursor.getColumnIndex(projection[0]);
       String picturePath = cursor.getString(columnIndex);
       cursor.close();
       Log.d("Picture Path", picturePath);
     }
     catch(Exception e) {
       Log.e("Path Error", e.toString());
     }
   }
 }

我收到此错误:

java.lang.NullPointerException

编辑

忘了提到我正在使用 Kitkat。看来我的问题与 KitKat 相关。我发现这个(见下文)帮助我让我的应用正常工作:

Android Gallery on KitKat returns different Uri for Intent.ACTION_GET_CONTENT

Answer 1

在你的项目中添加这个类

ImageFilePath.java

import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.provider.DocumentsContract;
import android.provider.MediaStore;

//import android.provider.<span id="IL_AD11" class="IL_AD">MediaStore</span>;

@SuppressLint("NewApi")
@TargetApi(Build.VERSION_CODES.KITKAT)
public class ImageFilePath {

    /**
     * Method for return file path of Gallery image
     *
     * @param context
     * @param uri
     * @return path of the selected image file from gallery
     */
    static String nopath = "Select Video Only";

    @TargetApi(Build.VERSION_CODES.KITKAT)
    @SuppressLint("NewApi")
    public static String getPath(final Context context, final Uri uri) {

        // check here to KITKAT or new version
        final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;

        // DocumentProvider
        if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {

            // ExternalStorageProvider
            if (isExternalStorageDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                if ("primary".equalsIgnoreCase(type)) {
                    return Environment.getExternalStorageDirectory() + "/"
                            + split[1];
                }
            }
            // DownloadsProvider
            else if (isDownloadsDocument(uri)) {

                final String id = DocumentsContract.getDocumentId(uri);
                final Uri contentUri = ContentUris.withAppendedId(
                        Uri.parse("content://downloads/public_downloads"),
                        Long.valueOf(id));

                return getDataColumn(context, contentUri, null, null);
            }
            // MediaProvider
            else if (isMediaDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                Uri contentUri = null;
                if ("image".equals(type)) {
                    contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
                } else if ("video".equals(type)) {
                    contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
                } else if ("audio".equals(type)) {
                    contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
                }

                final String selection = "_id=?";
                final String[] selectionArgs = new String[] { split[1] };

                return getDataColumn(context, contentUri, selection,
                        selectionArgs);
            }
        }
        // MediaStore (and general)
        else if ("content".equalsIgnoreCase(uri.getScheme())) {

            // Return the remote address
            if (isGooglePhotosUri(uri))
                return uri.getLastPathSegment();

            return getDataColumn(context, uri, null, null);
        }
        // File
        else if ("file".equalsIgnoreCase(uri.getScheme())) {
            return uri.getPath();
        }

        return nopath;
    }

    /**
     * Get the value of the data column for this Uri. This is <span id="IL_AD2"
     * class="IL_AD">useful</span> for MediaStore Uris, and other file-based
     * ContentProviders.
     *
     * @param context
     *            The context.
     * @param uri
     *            The Uri to query.
     * @param selection
     *            (Optional) Filter used in the query.
     * @param selectionArgs
     *            (Optional) Selection arguments used in the query.
     * @return The value of the _data column, which is typically a file path.
     */
    public static String getDataColumn(Context context, Uri uri,
                                       String selection, String[] selectionArgs) {

        Cursor cursor = null;
        final String column = "_data";
        final String[] projection = { column };

        try {
            cursor = context.getContentResolver().query(uri, projection,
                    selection, selectionArgs, null);
            if (cursor != null && cursor.moveToFirst()) {
                final int index = cursor.getColumnIndexOrThrow(column);
                return cursor.getString(index);
            }
        } finally {
            if (cursor != null)
                cursor.close();
        }
        return nopath;
    }

    /**
     * @param uri
     *            The Uri to check.
     * @return Whether the Uri authority is ExternalStorageProvider.
     */
    public static boolean isExternalStorageDocument(Uri uri) {
        return "com.android.externalstorage.documents".equals(uri
                .getAuthority());
    }

    /**
     * @param uri
     *            The Uri to check.
     * @return Whether the Uri authority is DownloadsProvider.
     */
    public static boolean isDownloadsDocument(Uri uri) {
        return "com.android.providers.downloads.documents".equals(uri
                .getAuthority());
    }

    /**
     * @param uri
     *            The Uri to check.
     * @return Whether the Uri authority is MediaProvider.
     */
    public static boolean isMediaDocument(Uri uri) {
        return "com.android.providers.media.documents".equals(uri
                .getAuthority());
    }

    /**
     * @param uri
     *            The Uri to check.
     * @return Whether the Uri authority is Google Photos.
     */
    public static boolean isGooglePhotosUri(Uri uri) {
        return "com.google.android.apps.photos.content".equals(uri
                .getAuthority());
    }
}

在你的 onActivityResult

 @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == PICK_IMAGE_REQUEST && resultCode == RESULT_OK && data != null && data.getData() != null) {

            Uri uri = data.getData();


            realPath = ImageFilePath.getPath(SignupActivity.this, data.getData());
//                realPath = RealPathUtil.getRealPathFromURI_API19(this, data.getData());

            Log.i(TAG, "onActivityResult: file path : " + realPath);
            try {
                Bitmap bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), uri);
                // Log.d(TAG, String.valueOf(bitmap));

                ImageView imageView = (ImageView) findViewById(R.id.img_profile);
                imageView.setImageBitmap(bitmap);
                imageView.setVisibility(View.VISIBLE);

            } catch (IOException e) {
                e.printStackTrace();
            }
        } else {
            Toast.makeText(this, "Something Went Wrong", Toast.LENGTH_SHORT).show();
        }

    }