打开pdf文件错误:无法访问此文件检查位置或网络,然后重试.Android 6 Marshmallow

Question

我试图从外部存储器获取文件,然后我必须使用意图将该文件发送到pdf阅读器.以前下面的代码工作正常,但安装Android 6(Marshmallow更新)后,我的代码无法正常工作并获取Toast消息

" 无法访问此文件检查位置或网络,然后重试."

(这是由于新的Android运行时权限).我刚尝试了所有的解决方案(内容提供商等,但没有工作)任何解决方案？

 File file = new File(getFilesDir(), "myfile.pdf");
 Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setDataAndType(Uri.fromFile(file), "application/pdf");
        intent.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);
        Intent intentChooser = Intent.createChooser(intent, "Choose Pdf Application");
        try {
            startActivity(intentChooser);
        } catch (ActivityNotFoundException e) {
            //com.adobe.reader
            startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("https://play.google.com/store/apps/details?id=com.adobe.reader")));
        }

Answer 1

在回顾上面的答案之后,最简单的解决方案如下.

    Uri pdf = FileProvider.getUriForFile(this, this.getApplicationContext().getPackageName() + ".provider", file);

    Intent pdfOpenintent = new Intent(Intent.ACTION_VIEW);
    pdfOpenintent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_ACTIVITY_CLEAR_TOP);
    pdfOpenintent.setDataAndType(pdf, "application/pdf");

    try {
        startActivity(pdfOpenintent);
    } catch (ActivityNotFoundException e) {
        // handle no application here....
    }

关键是同时设置FLAG_GRANT_READ_URI_PERMISSION和FLAG_ACTIVITY_CLEAR_TOP.

确保在ApplicationManifest.xml中声明了您的提供程序

<provider
        android:name="android.support.v4.content.FileProvider"
        android:authorities="${applicationId}.provider"
        android:exported="false"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/provider_paths"/>
    </provider>

Hers是provider_paths文件

<?xml version="1.0" encoding="utf-8"?>
<paths>
    <external-path name="external_files" path="."/>
</paths>

Answer 2

刚刚找到了适用于旧版和新版 Android 操作系统的可行解决方案：

步骤1： 创建一个类名SampleContentProvider

import android.content.ContentProvider;
import android.content.ContentValues;
import android.database.Cursor;
import android.net.Uri;
import android.os.ParcelFileDescriptor;

import java.io.File;
import java.io.FileNotFoundException;

/**
 * Created by naveed on 7/2/16.
 */
public class SampleContentProvider extends ContentProvider {

    @Override
    public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException {
        File privateFile = new File(uri.getPath());
        return ParcelFileDescriptor.open(privateFile, ParcelFileDescriptor.MODE_READ_ONLY);
    }

    @Override
    public boolean onCreate() {
        return false;
    }

    @Override
    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
        return null;
    }

    @Override
    public String getType(Uri uri) {
        return null;
    }

    @Override
    public Uri insert(Uri uri, ContentValues values) {
        return null;
    }

    @Override
    public int delete(Uri uri, String selection, String[] selectionArgs) {
        return 0;
    }

    @Override
    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
        return 0;
    }
}

步骤2：在清单的应用程序主体 中添加提供者：

<provider
        android:name=".SampleContentProvider"
        android:authorities="your_package_name"
        android:exported="true" />

第 3 步：现在最后使用Uri将 文件绝对路径传递给意图

  Intent intent = new Intent(Intent.ACTION_VIEW);
        File file = new File(getFilesDir(), "myfile.pdf");
        String absoluteFilePath = file.getAbsolutePath();
        String mimeType = "application/pdf";
        Uri uri = Uri.parse("content://"+"Your_package_name"+"/" + absoluteFilePath);
        intent.setDataAndType(uri, mimeType);
        Intent intentChooser = Intent.createChooser(intent, "Choose Pdf Application");
        startActivity(intentChooser);

我希望这能帮到您。感谢大家的帮助。

Answer 3

使用FileProvider(无论如何,这是自Android Nougat以来接受的方法 - 否则你将获得android.os.FileUriExposedException)然后不要忘记授予它所需的所有软件包的权限:

Uri uri = FileProvider.getUriForFile(
                                context,
                                context.getApplicationContext().getPackageName(), myFile);

                        Intent pdfIntent = new Intent(Intent.ACTION_VIEW);
                        pdfIntent.setDataAndType(apkURI, "application/pdf");
                        pdfIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
                        pdfIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                        grantAllUriPermissions(context, pdfIntent, apkURI);

地点grantAllUriPermissions():

private void grantAllUriPermissions(Context context, Intent intent, Uri uri) {
        List<ResolveInfo> resInfoList = context.getPackageManager().queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY);
        for (ResolveInfo resolveInfo : resInfoList) {
            String packageName = resolveInfo.activityInfo.packageName;
            context.grantUriPermission(packageName, uri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);
        }
}