我正在使用 DownloadManager 从 Internet 下载图像,并希望在 Gallery 应用程序中显示它们。我将图像保存到默认的“下载”目录。下载工作正常,我收到成功通知。图库应用打开,但不显示图像。可能是什么问题?
这是我的代码:
Cursor cursor = ((DownloadManager) getSystemService(DOWNLOAD_SERVICE)).query(ImageDownloadQuery);
if (cursor.moveToFirst()) {
String path = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_LOCAL_URI));
File file = new File(URI.create(path));
Uri uri = FileProvider.getUriForFile(ConversationDetailsActivity.this,
BuildConfig.APPLICATION_ID + ".fileprovider",
file);
Intent viewIntent = new Intent(Intent.ACTION_VIEW, uri);
viewIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
viewIntent.setType(cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_MEDIA_TYPE)));
if (getPackageManager().resolveActivity(viewIntent, 0) != null) { // checking if there is an app installed that can handle this type of files
startActivity(viewIntent);
} else { // app that can view this file type is not found
Toast.makeText(getBaseContext(), "Please install an application to view this type of files", Toast.LENGTH_SHORT).show();
}
}
文件提供者路径:
<paths>
<cache-path
name="cache"
path=""
/>
<external-path
name="download"
path="Download/"
/>
</paths>
和 list :
<provider
android:name="android.support.v4.content.FileProvider"
android:authorities="${applicationId}.fileprovider"
android:exported="false"
android:grantUriPermissions="true"
>
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/provider_paths"
/>
</provider>
这是为那些想知道的人准备的解决方案。请记住始终设置意向数据和类型。设置一个清除另一个。
DownloadManager.Query ImageDownloadQuery = new DownloadManager.Query();
ImageDownloadQuery.setFilterById(referenceId);
Cursor cursor = ((DownloadManager) getSystemService(DOWNLOAD_SERVICE)).query(ImageDownloadQuery);
if (cursor.moveToFirst()) {
String path = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_LOCAL_URI));
File file = new File(URI.create(path));
Uri uri = FileProvider.getUriForFile(ConversationDetailsActivity.this,
BuildConfig.APPLICATION_ID + ".fileprovider",
file);
Intent viewIntent = new Intent(Intent.ACTION_VIEW);
viewIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
viewIntent.setDataAndType(uri, cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_MEDIA_TYPE)));
if (getPackageManager().resolveActivity(viewIntent, 0) != null) { // checking if there is an app installed that can handle this type of files
startActivity(viewIntent);
} else { // app that can view this file type is not found
Toast.makeText(getBaseContext(), "Please install an application to view this type of files", Toast.LENGTH_SHORT).show();
}
}
最佳答案
我的错。我在没有设置数据的情况下设置了 Intent 类型,所以它清除了 Uri。检查原始问题的答案。
关于Android 查看用 DownloadManager 下载的图片,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/41567946/