java - 从 uri android 加载图像

Question

我目前正在尝试将我保存到 MySQLite 数据库中的图像的 Uri 加载到 RecyclerView 中。

RecyclerViewAdapter 的代码:

public void onBindViewHolder(MyCatchesAdapter.MyViewHolder holder, int position) {
    MyCatch myCatch = myCatchArrayList.get(position);
    holder.txtName.setText(myCatch.get_name());
    holder.txtLocation.setText(myCatch.get_location());
    holder.txtDate.setText(myCatch.get_date());

    holder.catchImage.setImageURI(Uri.parse(myCatch.get_catchImage()));
}

除图像外，所有数据均加载到回收器 View 中。我从 Logcat 得到以下内容

Unable to open content: content://com.android.externalstorage.documents/document/primary%3ADownload%2Fsunrise.png

java.lang.SecurityException: Permission Denial: opening provider com.android.externalstorage.ExternalStorageProvider from ProcessRecord
{ee1a504 28074:com.example.pavlos.myproject/u0a74} (pid=28074, uid=10074) requires android.permission.MANAGE_DOCUMENTS or android.permission.MANAGE_DOCUMENTS

我的 list 权限是:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.MANAGE_DOCUMENTS"/>

我有什么遗漏的吗？

编辑: 我如何获取 Uri:

catchImage.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent();
            intent.setType("image/*");
            intent.setAction(Intent.ACTION_GET_CONTENT);
            startActivityForResult(Intent.createChooser(intent,
                    "Select Picture"), SELECT_PICTURE);
        }
    });

public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == RESULT_OK) {
        if (requestCode == SELECT_PICTURE) {
            Uri selectedImageUri = data.getData();
            selectedImagePath = getPath(selectedImageUri);
            catchImage.setImageURI(selectedImageUri);
            imagePath = selectedImageUri;
            Log.d("imagePath","URI "+selectedImageUri);
        }
    }
}
public String getPath(Uri uri) {
    // just some safety built in
    if( uri == null ) {
        // TODO perform some logging or show user feedback
        return null;
    }
    // try to retrieve the image from the media store first
    // this will only work for images selected from gallery
    String[] projection = { MediaStore.Images.Media.DATA };
    Cursor cursor = managedQuery(uri, projection, null, null, null);
    if( cursor != null ){
        int column_index = cursor
                .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        String path = cursor.getString(column_index);
        cursor.close();
        return path;
    }
    // this is our fallback here
    return uri.getPath();
}

Answer 1

首先，getPath() 是完全错误的。最好的情况是，它适用于从 MediaStore 返回的图像的某些子集。彻底摆脱它。使用an image-loading library填充您的ImageView。

就您的问题而言，只要该 Activity 实例存在，您的 Activity 就可以使用从 ACTION_GET_CONTENT 返回的 Uri 。当且仅当您包含 FLAG_GRANT_READ_URI_PERMISSION 时，您才可以将该 Uri 传递给其他组件(例如另一个 Activity)。一旦您的进程终止，您将失去访问该内容的所有权利。因此，请停止将 Uri 持久保存到数据库，或切换到 ACTION_OPEN_DOCUMENT 并获取可持久 Uri 权限。