Android-如何从原始文件获取Uri？

Question

我正在尝试Uri从文件raw夹中包含在项目中的原始文件获取。但是FileNotFoundException无论如何，我都会得到一个。

该文件是一个.wav文件，也尝试过使用.mp4，也不起作用。使用MediaPlayerDOES 播放两个文件都可以。

的Uri回报：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)

Answer 1

尝试这种方法，getResources().openRawResource(ResourceID)用作您的inputStream。沿着这个地方：

//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

编辑：如果您使用上述方法，请删除这些代码

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

希望这有帮助，祝你好运！^^