尽管代码看起来不错，但应用程序无法播放 SD 卡中的视频

Question

我使用下面的代码使用 Android 的视频视图播放我的 SD 卡中的视频。我在外部存储根目录下放置了一个名为Video.mp4 的视频文件。但是当在我的智能手机上启动我的应用程序并使用下面的 Video.java 代码切换到我的视频 activity 时，我看到一个带有确定按钮的通知，说视频无法播放。（德语："Video kann nicht wiedergegeben werden."）

我的 AndroidManifest.xml 中是否缺少权限？

提前感谢您的任何提示和帮助。

package com.noureddine_ouertani.www.wocelli50;

import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.widget.MediaController;
import android.widget.VideoView;


public class Video extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_video);
        getSupportActionBar().setHomeButtonEnabled(true);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        VideoView v = (VideoView) findViewById(R.id.videoView);

        v.setVideoURI(Uri.parse(Environment.getExternalStorageDirectory().getPath() + "/Video.mp4"));
        //Set media controller buttons
        v.setMediaController(new MediaController(this));
        v.requestFocus();
        v.start(); //start Playback

    }
}

编辑： @Alexandre Martin：感谢您的回答。在我的应用程序中嵌入视频没有一般问题。当我创建一个原始文件夹并将视频 testvideo.mp4 放入其中然后替换

v.setVideoURI(Uri.parse(Environment.getExternalStorageDirectory().getPath() + "/Video.mp4"));

和

 v.setVideoURI(Uri.parse("android.resource://com.noureddine_ouertani.www.wocelli50/"+ R.raw.testvideo));

在我的代码中，一切正常，我看到我的视频在我的应用程序中播放。备注：我必须将 Video.mp4 重命名为 testvideo.mp4，因为从 raw 文件夹调用的视频不允许使用大写字母。我的问题只是获取我 SD 卡上视频的路径。

@Lonnie Zamora:感谢您的回答。这似乎不是格式或编码问题。 testvideo.mp4 只是 Video.mp4 重命名并放在我的原始文件夹中。它与下面的代码配合得很好：

package com.noureddine_ouertani.www.wocelli50;

import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.MediaController;
import android.widget.VideoView;


public class Video extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_video);
        getSupportActionBar().setHomeButtonEnabled(true);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        VideoView v = (VideoView) findViewById(R.id.videoView);

        v.setVideoURI(Uri.parse("android.resource://com.noureddine_ouertani.www.wocelli50/"+ R.raw.testvideo));
        //Set media controller buttons
        v.setMediaController(new MediaController(this));
        v.requestFocus();
        v.start(); //start Playback

    }
}

@CommonsWare:感谢您的回答。我尝试了你的建议，但没有解决问题。

此致，

编辑 2: @CommonsWare 这似乎不是缺少权限或缺少权限请求的问题。我实现了以下运行时权限逻辑并看到 "Video is playing. No permissioon request was needed." 这对我来说意味着 (Manifest.permission.READ_EXTERNAL_STORAGE == PackageManager.PERMISSION_GRANTED) 是真的

package com.noureddine_ouertani.www.wocelli50;

import android.Manifest;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.widget.MediaController;
import android.widget.Toast;
import android.widget.VideoView;

public class Video extends AppCompatActivity {

    final int REQUEST_READ_EXTERNAL_STORAGE = 1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_video);


        if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {



            // Should we show an explanation?
            if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.READ_EXTERNAL_STORAGE)) {
                Toast.makeText(getApplicationContext(), "Show explanation for requesting the permission to read the SD-card.", Toast.LENGTH_SHORT).show();
                // Show an expanation to the user *asynchronously* -- don't block
                // this thread waiting for the user's response! After the user
                // sees the explanation, try again to request the permission.

            } else {

                // No explanation needed, we can request the permission.
                Toast.makeText(getApplicationContext(), "No explanation needed, we can request the permission.", Toast.LENGTH_SHORT).show();
                ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, REQUEST_READ_EXTERNAL_STORAGE);

                // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
                // app-defined int constant. The callback method gets the
                // result of the request.
        }
        } else {
            playmyvideo();
            Toast.makeText(getApplicationContext(), "Video is playing. No permissioon request was needed.", Toast.LENGTH_SHORT).show();
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        switch (requestCode) {
            case REQUEST_READ_EXTERNAL_STORAGE: {
                // If request is cancelled, the result arrays are empty.
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    playmyvideo();
                    Toast.makeText(getApplicationContext(), "Video is playing after permissioon was granted.", Toast.LENGTH_SHORT).show();

                } else {
                    Toast.makeText(getApplicationContext(), "permission denied,Disable the functionality that depends on this permission.", Toast.LENGTH_SHORT).show();
                    // permission denied, boo! Disable the
                    // functionality that depends on this permission.
                }
                return;
            } 

            // other 'case' lines to check for other
            // permissions this app might request
        }
    }

    public void playmyvideo(){

        getSupportActionBar().setHomeButtonEnabled(true);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        VideoView v = (VideoView) findViewById(R.id.videoView);
        v.setVideoURI(Uri.parse(Environment.getExternalStorageDirectory().getPath() + "/testvideo.mp4"));
        //v.setVideoURI(Uri.parse("android.resource://com.noureddine_ouertani.www.wocelli50/"+ R.raw.testvideo));

        v.setMediaController(new MediaController(this));
        v.requestFocus();
        v.start(); //start Playback
        }
    }

Answer 1

替换

 Uri.parse(Environment.getExternalStorageDirectory().getPath() + "/Video.mp4")

（无效，因为缺少方案）

与：

Uri.fromFile(new File(Environment.getExternalStorageDirectory(), "Video.mp4"))

Answer 2

解决方案 @all 访问外部 SD 卡的解决方案：

v.setVideoURI(Uri.parse("/storage/sdcard1/testvideo.mp4"));

而不是

v.setVideoURI(Uri.parse(Environment.getExternalStorageDirectory().getPath() + "/testvideo.mp4"));

原因：

Environment.getExternalStorageDirectory().getPath() == "/storage/emulated/0"

Environment.getExternalStorageDirectory().getPath() 将路径传递到我的智能手机（HUAWEI P8）上的内部存储芯片，该芯片像 SD 卡一样安装但虽然不是外置 SD 卡。

尽管代码看起来不错，但应用程序无法播放 SD 卡中的视频

App can´t play a video from the SD-Card despite the fact that the code looks fine

android

video

sd-card