android实践：拍照图片在相册中不显示

问题：拉起系统相机拍照并存储到公共区域，图片文件可见，系统相册中却看不到

实现：

Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
File publicDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM);
String path = publicDir.getAbsolutePath() + "/Camera";
this.takePhotoFile = createImageFile(path);
if (VERSION.SDK_INT >= 24) {
    String pkName = activity.getPackageName();
    intent.putExtra(MediaStore.EXTRA_OUTPUT, FileProvider.getUriForFile(activity,pkName + ".fileProvider", takePhotoFile));
} else {
    intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(takePhotoFile));
}
intent.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION); // 授予临时写入权限
if (intent.resolveActivity(activity.getPackageManager()) != null) {
    activity.startActivity(intent);
}

private File createImageFile(String photoAbsolutePath) throws IOException {
        SimpleDateFormat format = new SimpleDateFormat("yyyyMMdd_HHmmss");
        String timeStamp = format.format(new Date());
        String imageFileName = timeStamp + ".jpg";
        File image = new File(photoAbsolutePath, imageFileName);
        return image;
    }

 //发送广播给系统，刷新数据库
 Uri uri = Uri.fromFile(takePhotoFile);
 Intent localIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, uri);
 mContext.sendBroadcast(localIntent);

<provider
    android:name="androidx.core.content.FileProvider"
    android:authorities="${applicationId}.fileProvider"
    android:exported="false"
    android:grantUriPermissions="true">
    <meta-data
        android:name="android.support.FILE_PROVIDER_PATHS"
        android:resource="@xml/file_paths" />
</provider>

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-path name="external_files" path="."/>
    <root-path name="root_path" path="." />
    <files-path name="files_path" path="." />
    <cache-path name="cache-path" path="." />
</paths>

总结：

1.需要发送广播给系统，刷新数据库

2.照片存储使用FileProvider