Android - 如何从原始文件获取Uri？ [英] Android - How to get Uri from raw file?

问题描述

我想从 raw 文件夹中包含在项目中的原始文件中获取 Uri 。
但无论如何我都会得到 FileNotFoundException 。

I am trying to get the Uri from a raw file I have included in the project in the raw folder. But I am getting a FileNotFoundException, no matter what.

该文件是 .wav 文件，也尝试使用 .mp4 ，也不起作用。
使用 MediaPlayer播放这两个文件是否正常工作。

The file is a .wav file, also tried it with a .mp4, also doesn't work. Playing both files with MediaPlayer DOES work.

Uri 返回： mark.dijkema.android.eindopdracht / 2130968576

我的代码：

package mark.dijkema.android.eindopdracht;

import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

import android.app.Activity;
import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioTrack;
import android.net.Uri;
import android.os.Bundle;

public class MainActivity extends Activity
{
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        PlayWaveFile();
    }

    private void PlayWaveFile()
    {
        // define the buffer size for audio track
        int minBufferSize = AudioTrack.getMinBufferSize(8000, AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT);
        int bufferSize = 512;
        AudioTrack audioTrack = new AudioTrack(AudioManager.STREAM_VOICE_CALL, 8000, AudioFormat.CHANNEL_OUT_MONO,
            AudioFormat.ENCODING_PCM_16BIT, minBufferSize, AudioTrack.MODE_STREAM);

        Uri url = Uri.parse("android.resource://" + getPackageName() + "/" + R.raw.usa_for_africa_we_are_the_world);
        File file = new File(url.toString());

        int count = 0;
        byte[] data = new byte[bufferSize];

        try {
            FileInputStream fileInputStream = new FileInputStream(file);
            DataInputStream dataInputStream = new DataInputStream(fileInputStream);
            audioTrack.play();

            while((count = dataInputStream.read(data, 0, bufferSize)) > -1)
            {
                audioTrack.write(data, 0, count);
            }

            audioTrack.stop();
            audioTrack.release();
            dataInputStream.close();
            fileInputStream.close();
        }
        catch (FileNotFoundException e)
        {
            e.printStackTrace();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
    }
}

错误：

java.io.FileNotFoundException: /mark.dijkema.android.eindopdracht/2130968576: open failed: ENOENT (No such file or directory)

推荐答案

试试这种方法，使用 getResources （）。openRawResource（ResourceID）作为您的inputStream。
某处：

Try this approach, use getResources().openRawResource(ResourceID) as your inputStream. Somewhere along this :

//FileInputStream fileInputStream = new FileInputStream(file);
InputStream inputStream  = getResources().openRawResource(R.raw.usa_for_africa_we_are_the_world);
DataInputStream dataInputStream = new DataInputStream(inputStream);
audioTrack.play();

getResources（）。openRawResource（ResourceID）返回一个InputStream

getResources().openRawResource(ResourceID) returns an InputStream

编辑：如果你使用上述方法删除这些代码

EDIT : Remove these code if you use the above approach

Uri url = Uri.parse("android.resource://" + getPackageName() + "/" + R.raw.usa_for_africa_we_are_the_world);
File file = new File(url.toString());

希望这会有所帮助，祝你好运！ ^^

Hope this helps, Good Luck! ^^

这篇关于Android - 如何从原始文件获取Uri？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！