android 获取路径

在 Android 开发中，获取文件路径的方法有很多种。其中，常用的方法有以下几种：

1. 通过 Uri 获取路径

public String getRealPathFromUri(Uri uri) {
    String[] projection = {MediaStore.Images.Media.DATA};
    Cursor cursor = getContentResolver().query(uri, projection, null, null, null);
    int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
    cursor.moveToFirst();
    String filePath = cursor.getString(column_index);
    cursor.close();
    return filePath;
}

2. 通过 FileProvider 获取路径

public static Uri getUriFromFile(Context context, File file) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
        return FileProvider.getUriForFile(context, context.getPackageName() + ".fileprovider", file);
    } else {
        return Uri.fromFile(file);
    }
}

public String getRealPathFromUri(Uri uri) {
    String filePath = "";
    if (DocumentsContract.isDocumentUri(this, uri)) {
        String documentId = DocumentsContract.getDocumentId(uri);
        if ("com.android.providers.media.documents".equals(uri.getAuthority())) {
            String id = documentId.split(":")[1];
            String selection = MediaStore.Images.Media._ID + "=" + id;
            filePath = getImagePath(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, selection);
        } else if ("com.android.providers.downloads.documents".equals(uri.getAuthority())) {
            Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(documentId));
            filePath = getImagePath(contentUri, null);
        }
    } else if ("content".equalsIgnoreCase(uri.getScheme())) {
        filePath = getImagePath(uri, null);
    } else if ("file".equalsIgnoreCase(uri.getScheme())) {
        filePath = uri.getPath();
    }
    return filePath;
}

public String getImagePath(Uri uri, String selection) {
    String path = null;
    Cursor cursor = getContentResolver().query(uri, null, selection, null, null);
    if (cursor != null) {
        if (cursor.moveToFirst()) {
            path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
        }
        cursor.close();
    }
    return path;
}

3. 直接获取文件路径

File file = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/test.txt");
String filePath = file.getAbsolutePath();