如何在 Android 中使用内容 uri（不是文件 uri）传递带有 Intent 的单个图像
（我读过很多类似的问题，但请耐心等待）
我需要从一个 Activity（自定义相机 acitvity）发送一张图像，其中第二个 Activity 是通过 Google API 将图像上传到 Picasa 网络相册。
我发现的每个示例都是这样的：
File f = new File(cacheDir, "image_name.jpg");
Intent intent = new Intent(Intent.ACTION_SEND);
intent.setType("image/jpeg");
intent.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(f));
startActivity(intent);
当我使用标准 Android Picasa 上传活动（或任何其他共享应用程序）时，效果非常好。我还可以通过 我正在使用的 Picasa 示例 应用程序，在从图库/相机等共享图像时。
但我不知道如何构建使用“content://”的 Intent ---" uri 并传递这个到另一个应用程序（无论是本示例应用程序还是 Picasa 标准应用程序）...
具体来说：如何创建与下面的代码兼容的 Intent（即使用“content://”uri 而不是“file://” “乌里）？
static class SendData {
String fileName;
Uri uri;
String contentType;
long contentLength;
SendData(Intent intent, ContentResolver contentResolver) {
Bundle extras = intent.getExtras();
if (extras.containsKey(Intent.EXTRA_STREAM)) {
Uri uri = this.uri = (Uri) extras.get(Intent.EXTRA_STREAM);
String scheme = uri.getScheme();
if (scheme.equals("content")) {
Cursor cursor = contentResolver.query(uri, null, null, null, null);
cursor.moveToFirst();
this.fileName = cursor.getString(cursor.getColumnIndexOrThrow(Images.Media.DISPLAY_NAME));
this.contentType = intent.getType();
this.contentLength = cursor.getLong(cursor.getColumnIndexOrThrow(Images.Media.SIZE));
}
}
}
}
- 手动从文件 uri 检索文件信息会导致应用程序中使用的 Google Http 请求出现 NullPointerException。
对 Content uri 进行硬编码是可行的。例如：
uploadIntent.putExtra(Intent.EXTRA_STREAM, Uri.parse("content://media/external/images/media/11"));
(I have read a lot of similar questions, but bear with me here)
I need to send an image from one Activity (custom camera acitvity), where the second Activity is to upload the image to Picasa Web Album via Google API.
Every example I've found goes something like this:
File f = new File(cacheDir, "image_name.jpg");
Intent intent = new Intent(Intent.ACTION_SEND);
intent.setType("image/jpeg");
intent.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(f));
startActivity(intent);
This works perfectly fine when I use the standard Android Picasa upload activity (or any other sharing app). I can also upload photos via the Picasa example app I am using, when sharing the image from gallery/camera etc.
But I cannot figure out how to build an Intent which uses a "content://---" uri and pass this to another application (neither for this example app or the Picasa standard app)...
Specificially: How can I create an Intent which is compatible with the code below (i.e. uses "content://" uri instead of "file://" uri)?
static class SendData {
String fileName;
Uri uri;
String contentType;
long contentLength;
SendData(Intent intent, ContentResolver contentResolver) {
Bundle extras = intent.getExtras();
if (extras.containsKey(Intent.EXTRA_STREAM)) {
Uri uri = this.uri = (Uri) extras.get(Intent.EXTRA_STREAM);
String scheme = uri.getScheme();
if (scheme.equals("content")) {
Cursor cursor = contentResolver.query(uri, null, null, null, null);
cursor.moveToFirst();
this.fileName = cursor.getString(cursor.getColumnIndexOrThrow(Images.Media.DISPLAY_NAME));
this.contentType = intent.getType();
this.contentLength = cursor.getLong(cursor.getColumnIndexOrThrow(Images.Media.SIZE));
}
}
}
}
- Retrieving the File-information from a File uri manually leads to NullPointerException with the Google Http Request used in the app.
Hardcoding the Content uri works. E.g:
uploadIntent.putExtra(Intent.EXTRA_STREAM, Uri.parse("content://media/external/images/media/11"));
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与媒体文件相关的信息由
MediaStore存储，它是一个 ContentProvider (http://developer.android.com/reference/android/provider/MediaStore.Images.html)MediaStore.Images.DATA列对应于文件路径，MediaStore.Images._ID 列对应于 ID。
您需要查询与文件路径相对应的 ID，然后从中创建一个 ContentUri（如果图像位于外部存储上，则为 MediaStore.Images.Media.EXTERNAL_CONTENT_URI + id，我会尝试考虑一个将 ID 转换为内容 Uri 的更好方法）。
http://developer.android.com/reference/android/provider/MediaStore.Images.Media.html#query(android.content.ContentResolver, android.net.Uri，java.lang.String[]
Information related to Media files is stored by the
MediaStore, which is a ContentProvider (http://developer.android.com/reference/android/provider/MediaStore.Images.html)MediaStore.Images.DATA column corresponds to the file path and MediaStore.Images._ID column corresponds to the ID.
You need to query for the ID corresponding to your file path and then create a ContentUri out of it (which will be MediaStore.Images.Media.EXTERNAL_CONTENT_URI + id if the image is on the external storage, I'll try to think of a better way to translate the ID into a Content Uri).
http://developer.android.com/reference/android/provider/MediaStore.Images.Media.html#query(android.content.ContentResolver, android.net.Uri, java.lang.String[]