13_拍照、录像和音频

　　Goolgle 从Android OS 2.0版本开始提供照相API功能，可以开发控制照相功能，更在Android OS 2.3版本支持多个相机功能，让相机应用程序可以选择和配置相机。简要介绍拍照、录像和音频。

1. 拍照

package cn.eoe.system.camera;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;

public class Main extends Activity implements OnClickListener {
    private ImageView imageView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Button btnTakePicture = (Button) findViewById(R.id.btnTakePicture);
        btnTakePicture.setOnClickListener(this);

        imageView = (ImageView) findViewById(R.id.imageview);

    }

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == 1) {
            // 点了拍照按钮，是一个小的对号。
            if (resultCode == Activity.RESULT_OK) {
                // 获得图像的字节流
                Bitmap cameraBitmap = (Bitmap) data.getExtras().get("data");
                imageView.setImageBitmap(cameraBitmap);

            }
        }
    }

    // 窗口返回，所以使用startActivityForResult
    public void onClick(View view) {
        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        startActivityForResult(intent, 1);
    }

}

2. 录像

package cn.eoe.record.video;

import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.MediaController;
import android.widget.VideoView;

public class Main extends Activity implements OnClickListener {
    public VideoView videoView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button btnTakePicture = (Button) findViewById(R.id.btnTakePicture);
        btnTakePicture.setOnClickListener(this);

        videoView = (VideoView) findViewById(R.id.videoview);

    }

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == 1) {
            if (resultCode == Activity.RESULT_OK) {
                // 视频比较大，不可能放在Intent里面。视频的路径存在系统数据库里面，返回了一个URI
                // 通过URI找到视频存放路径
                Uri uri = data.getData();
                Cursor cursor = this.getContentResolver().query(uri, null,
                        null, null, null);

                if (cursor.moveToFirst()) {
                    String videoPath = cursor.getString(cursor
                            .getColumnIndex("_data"));
                    videoView.setVideoURI(Uri.parse(videoPath));
                    videoView.setMediaController(new MediaController(this));
                    videoView.start();
                }
            }
        }
    }

    public void onClick(View view) {
        Intent intent = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
        startActivityForResult(intent, 1);

    }
}

3. 音频

package cn.eoe.play.music;

import android.app.Activity;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class Main extends Activity implements OnClickListener,
        OnCompletionListener {
    private MediaPlayer mediaPlayer;
    private Button btnPause;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Button btnStart1 = (Button) findViewById(R.id.btnStart1);
        Button btnStart2 = (Button) findViewById(R.id.btnStart2);

        Button btnStop = (Button) findViewById(R.id.btnStop);

        btnPause = (Button) findViewById(R.id.btnPause);

        btnStart1.setOnClickListener(this);
        btnStart2.setOnClickListener(this);
        btnStop.setOnClickListener(this);
        btnPause.setOnClickListener(this);

    }

    public void onCompletion(MediaPlayer mp) {
        mp.release();
        setTitle("资源已经释放");

    }

    public void onClick(View view) {
        try {
            switch (view.getId()) {
            case R.id.btnStart1: // 播放音频资源
                mediaPlayer = MediaPlayer.create(this, R.raw.music);
                mediaPlayer.setOnCompletionListener(this);

                mediaPlayer.start();
                break;
                
            case R.id.btnStart2:// 播放SD卡上的音频文件（/sdcard/music.mp3)
                mediaPlayer = new MediaPlayer();
                mediaPlayer.setDataSource("/sdcard/music.mp3");

                mediaPlayer.prepare();
                mediaPlayer.start();
                break;

            case R.id.btnStop:
                if (mediaPlayer != null) {
                    if (mediaPlayer.isPlaying())
                        mediaPlayer.stop();
                }
                break;

            case R.id.btnPause:
                if (mediaPlayer != null) {
                    if ("播放".equals(btnPause.getText().toString())) {
                        mediaPlayer.start();
                        btnPause.setText("暂停");

                    } else if ("暂停".equals(btnPause.getText().toString())) {
                        mediaPlayer.pause();
                        btnPause.setText("播放");
                    }
                }
                break;
                
            default:
                break;
            }
        } catch (Exception e) {
            // TODO: handle exception
        }
    }
}