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 Android教程網 >> Android技術 >> 關於Android編程 >> 安卓小案例收集四（多媒體）

安卓小案例收集四（多媒體）

編輯：關於Android編程

加載大圖片

 @Override
 protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
  }


  public void click(View v){
    Options opts = new Options();
    //只請求圖片寬高，不解析圖片像素
    opts.inJustDecodeBounds = true;
    //返回null，獲取圖片寬高，保存在opts對象中
    BitmapFactory.decodeFile("sdcard/dog.jpg", opts);
    //獲取圖片寬高
    int imageWidth = opts.outWidth;
    int imageHeight = opts.outHeight;

    //獲取屏幕寬高
    Display dp = getWindowManager().getDefaultDisplay();
int screenWidth = dp.getWidth();
    int screenHeight = dp.getHeight();

    //計算縮放比例
    int scale = 1;
    int scaleWidth = imageWidth / screenWidth;
    int scaleHeight = imageHeight / screenHeight;

    //判斷取哪個比例
    if(scaleWidth >= scaleHeight && scaleWidth > 1){
        scale = scaleWidth;
    }
    else if(scaleWidth < scaleHeight && scaleHeight > 1){
        scale = scaleHeight;
    }

    //設置縮小比例
    opts.inSampleSize = scale;
    opts.inJustDecodeBounds = false;
    //獲取縮小後的圖片的像素信息
    Bitmap bm = BitmapFactory.decodeFile("sdcard/dog.jpg", opts);

    ImageView iv = (ImageView) findViewById(R.id.iv);
    iv.setImageBitmap(bm);

  }

創建圖片副本

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    //加載原圖
    Bitmap bmSrc = BitmapFactory.decodeResource(getResources(), R.drawable.photo3);

    //創建副本
    //1.創建與原圖一模一樣大小的bitmap對象，該對象中目前是沒有內容的，可以比喻為創建了和原圖一樣大小的白紙
    Bitmap bmCopy = Bitmap.createBitmap(bmSrc.getWidth(), bmSrc.getHeight(), bmSrc.getConfig());
    //2.創建畫筆對象
    Paint paint = new Paint();
    //3.創建畫板，把白紙鋪到畫板上
    Canvas canvas = new Canvas(bmCopy);
    //4.開始作畫
    canvas.drawBitmap(bmSrc, new Matrix(), paint);

    ImageView iv_src = (ImageView) findViewById(R.id.iv_src);
    iv_src.setImageBitmap(bmSrc);
    ImageView iv_copy = (ImageView) findViewById(R.id.iv_copy);
    iv_copy.setImageBitmap(bmCopy);
}

簡單圖片特效

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    //加載原圖
    Bitmap bmSrc = BitmapFactory.decodeResource(getResources(), R.drawable.photo3);

    //創建副本
    //1.創建與原圖一模一樣大小的bitmap對象，該對象中目前是沒有內容的，可以比喻為創建了和原圖一樣大小的白紙
    Bitmap bmCopy = Bitmap.createBitmap(bmSrc.getWidth(), bmSrc.getHeight(), bmSrc.getConfig());
    //2.創建畫筆對象
    Paint paint = new Paint();
    //3.創建畫板，把白紙鋪到畫板上
    Canvas canvas = new Canvas(bmCopy);

    Matrix mt = new Matrix();

    //平移效果，指定平移距離
//        mt.setTranslate(20, 10);
    //縮放效果，指定縮放比例
//        mt.setScale(2, 0.5f, bmCopy.getWidth() / 2, bmCopy.getHeight() / 2);
    //旋轉效果
//        mt.setRotate(45, bmCopy.getWidth() / 2, bmCopy.getHeight() / 2);

    //鏡面效果
//        mt.setScale(-1, 1);
//        mt.postTranslate(bmCopy.getWidth(), 0);

    //倒影效果
    mt.setScale(1, -1);
    mt.postTranslate(0, bmCopy.getHeight());

    canvas.drawBitmap(bmSrc, mt, paint);

    ImageView iv_src = (ImageView) findViewById(R.id.iv_src);
    iv_src.setImageBitmap(bmSrc);
    ImageView iv_copy = (ImageView) findViewById(R.id.iv_copy);
    iv_copy.setImageBitmap(bmCopy);
}

畫板

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Bitmap bmSrc = BitmapFactory.decodeResource(getResources(), R.drawable.bg);
    //白紙
    bmCopy = Bitmap.createBitmap(bmSrc.getWidth(), bmSrc.getHeight(), bmSrc.getConfig());
    //筆
    paint = new Paint();
    //畫板
    canvas = new Canvas(bmCopy);
    //作畫
    canvas.drawBitmap(bmSrc, new Matrix(), paint);

    iv = (ImageView) findViewById(R.id.iv);
    iv.setImageBitmap(bmCopy);

    iv.setOnTouchListener(new OnTouchListener() {

        //用戶手指只要觸摸屏幕，就會產生觸摸事件
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            //判斷觸摸事件的類型
            switch (event.getAction()) {
            //手指觸摸
            case MotionEvent.ACTION_DOWN:
                //觸摸事件中會包含手指觸摸的坐標
                startX = (int) event.getX();
                startY = (int) event.getY();
                break;
                //手指滑動
            case MotionEvent.ACTION_MOVE:
                int newX = (int) event.getX();
                int newY = (int) event.getY();
                //指定線的起點和終點
                canvas.drawLine(startX, startY, newX, newY, paint);
                iv.setImageBitmap(bmCopy);

                //把本此畫線的終點設置為下一次畫線的起點
                startX = newX;
                startY = newY;
                break;
                //手指抬起
            case MotionEvent.ACTION_UP:
                break;

            }
            //true表示告訴系統，這個觸摸事件由iv處理
            //false表示不處理該觸摸事件，事件往上傳遞
            return true;
        }
    });
}

public void red(View v){
    paint.setColor(Color.RED);
}

public void green(View v){
    paint.setColor(Color.GREEN);
}

public void brush(View v){
    //改變線條粗細
    paint.setStrokeWidth(8);
}

public void save(View v){
    File file = new File("sdcard/dazuo.png");
    FileOutputStream fos;
    try {
        fos = new FileOutputStream(file);
        //把圖片壓縮到本地文件
        bmCopy.compress(CompressFormat.PNG, 100, fos);
        fos.close();
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    //手動發一個sd卡就緒廣播
    Intent intent = new Intent();
    intent.setAction(Intent.ACTION_MEDIA_MOUNTED);
    intent.setData(Uri.fromFile(Environment.getExternalStorageDirectory()));
    sendBroadcast(intent);
}

模擬撕衣服

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    //加載圖片
    Bitmap bmSrc = BitmapFactory.decodeResource(getResources(), R.drawable.big2);
    final Bitmap bmCopy = Bitmap.createBitmap(bmSrc.getWidth(), bmSrc.getHeight(), bmSrc.getConfig());
    Paint paint = new Paint();
    Canvas canvas = new Canvas(bmCopy);
    canvas.drawBitmap(bmSrc, new Matrix(), paint);

    final ImageView iv = (ImageView) findViewById(R.id.iv);
    iv.setImageBitmap(bmCopy);

    iv.setOnTouchListener(new OnTouchListener() {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            switch (event.getAction()) {
            case MotionEvent.ACTION_MOVE:
                int x = (int) event.getX();
                int y = (int) event.getY();

                //把該坐標對應的像素，置為透明色
                for (int i = -5; i < 5; i++) {
                    for (int j = -5; j < 5; j++) {
                        if(Math.sqrt(i*i + j*j) <= 5){
                            if(x + i < bmCopy.getWidth() && y + j < bmCopy.getHeight()
                                    && x + i >= 0 && y + j >= 0)
                            //把指定坐標的像素置為指定的顏色
                            bmCopy.setPixel(x + i, y + j, Color.TRANSPARENT);
                        }
                    }
                }
                iv.setImageBitmap(bmCopy);
                break;

            }
            return true;
        }
    });
}

視頻播放

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    SurfaceView sv = (SurfaceView) findViewById(R.id.sv);
    //獲取surfaceview的控制器
    final SurfaceHolder holder = sv.getHolder();


//      Thread t = new Thread(){
//          @Override
//          public void run() {
//              try {
//                  sleep(200);
//              } catch (InterruptedException e) {
//                  // TODO Auto-generated catch block
//                  e.printStackTrace();
//              }
//              runOnUiThread(new Runnable() {
//                  @Override
//                  public void run() {
//                      MediaPlayer player = new MediaPlayer();
//                      player.reset();
//                      try {
//                          player.setDataSource("sdcard/2.3gp");
//                          //指定視頻播放在哪個surfaceview
//                          player.setDisplay(holder);
//                          player.prepare();
//                          player.start();
//                      } catch (Exception e) {
//                          // TODO Auto-generated catch block
//                          e.printStackTrace();
//                      }
//                  }
//              });
//          }
//      };
//      t.start();

    holder.addCallback(new Callback() {
        //surfaceview銷毀時會調用
        @Override
        public void surfaceDestroyed(SurfaceHolder holder) {
            if(player != null){
                //停止之前先保存播放進度
                progress = player.getCurrentPosition();
                player.stop();
                player.release();
                player = null;
            }
        }
        //surfaceview創建時會調用
        @Override
        public void surfaceCreated(SurfaceHolder holder) {
            if(player == null){
                player = new MediaPlayer();
                player.reset();
                try {
                    player.setDataSource("sdcard/2.3gp");
                    //指定視頻播放在哪個surfaceview
                    player.setDisplay(holder);
                    player.prepare();
                    //跳轉到上一次停止的地方繼續播放
                    player.seekTo(progress);
                    player.start();
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }

        }

        //surfaceview結構改變時會調用
        @Override
        public void surfaceChanged(SurfaceHolder holder, int format, int width,
                int height) {
            // TODO Auto-generated method stub

        }
    });
}

VideoView

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    VideoView vv = (VideoView) findViewById(R.id.vv);
    vv.setVideoPath("sdcard/2.3gp");
    vv.start();
}

照相和拍攝

public void click1(View v){
    //啟動拍照的Activity
    Intent intent = new Intent();
    intent.setAction(MediaStore.ACTION_IMAGE_CAPTURE);
    intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(new File("sdcard/haha.jpg")));
    startActivityForResult(intent, 10);
}

public void click2(View v){
    //啟動拍照的Activity
    Intent intent = new Intent();
    intent.setAction(MediaStore.ACTION_VIDEO_CAPTURE);
    intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(new File("sdcard/haha2.3gp")));
    intent.putExtra(MediaStore.EXTRA_VIDEO_QUALITY, 1);

    startActivityForResult(intent, 20);

}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    // TODO Auto-generated method stub
    super.onActivityResult(requestCode, resultCode, data);
    if(requestCode == 10){
        Toast.makeText(this, "拍照完畢", 0).show();
    }
    else if(requestCode == 20){
        Toast.makeText(this, "攝像完畢", 0).show();
    }
}

拍照預覽

public class MainActivity extends Activity {

     private Camera mCamera;
        private CameraPreview mPreview;

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

            if(checkCameraHardware(this)){
                // 創建攝像頭實例
                mCamera = getCameraInstance();
            }
            else{
                return;
            }
            //創建預覽類的對象
            mPreview = new CameraPreview(this, mCamera);
            FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
            //把預覽類設置為幀布局的子節點
            preview.addView(mPreview);


         // 給按鈕設置點擊偵聽
            Button captureButton = (Button) findViewById(R.id.button_capture);
            captureButton.setOnClickListener(
                new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        //自動聚焦
                        mCamera.autoFocus(new AutoFocusCallback() {

                            //聚焦完成調用
                            @Override
                            public void onAutoFocus(boolean success, Camera camera) {
                                 // 拍照
                                mCamera.takePicture(null, null, mPicture);

                            }
                        });

                    }
                }
            );
        }


    /** 檢測手機是否有攝像頭 */
    private boolean checkCameraHardware(Context context) {
        //檢測手機是否安裝有攝像頭應用
        if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)){
            // this device has a camera
            return true;
        } else {
            // no camera on this device
            return false;
        }
    }

    /** 一個獲取攝像頭實例的安全途徑 */
    public static Camera getCameraInstance(){
        Camera c = null;
        try {
            c = Camera.open(); // 獲取第一個後置攝像頭的實例
        }
        catch (Exception e){
            // Camera is not available (in use or does not exist)
        }
        return c; // returns null if camera is unavailable
    }


    private PictureCallback mPicture = new PictureCallback() {

        //拍照會調用此方法
        //data:照片的字節數組
        @Override
        public void onPictureTaken(byte[] data, Camera camera) {
            try {
                File pictureFile = new File("sdcard/mrplus.jpg");
                FileOutputStream fos = new FileOutputStream(pictureFile);
                fos.write(data);
                fos.close();
            } catch (FileNotFoundException e) {
                Log.d(CameraPreview.TAG, "File not found: " + e.getMessage());
            } catch (IOException e) {
                Log.d(CameraPreview.TAG, "Error accessing file: " + e.getMessage());
            } finally{
                //拍照完成後重新進入預覽
                camera.startPreview();
            }
        }
    };

}

預覽類：

public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
    public static final String TAG = "camera";
    private SurfaceHolder mHolder;
    private Camera mCamera;

    public CameraPreview(Context context, Camera camera) {
        super(context);
        mCamera = camera;

        // Install a SurfaceHolder.Callback so we get notified when the
        // underlying surface is created and destroyed.
        //獲取surfaceview的控制器
        mHolder = getHolder();
        //設置偵聽
        mHolder.addCallback(this);
        // deprecated setting, but required on Android versions prior to 3.0
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, now tell the camera where to draw the preview.
        try {
            //設置攝像頭的預覽界面顯示在holder對應的那個surfaceview
            mCamera.setPreviewDisplay(holder);
            //開始預覽
            mCamera.startPreview();
        } catch (IOException e) {
            Log.d(TAG, "Error setting camera preview: " + e.getMessage());
        }
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        // empty. Take care of releasing the Camera preview in your activity.
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        // If your preview can change or rotate, take care of those events here.
        // Make sure to stop the preview before resizing or reformatting it.

        if (mHolder.getSurface() == null){
          // preview surface does not exist
          return;
        }

        // 在對surfaceview做改變前，先停止預覽
        try {
            mCamera.stopPreview();
        } catch (Exception e){
          // ignore: tried to stop a non-existent preview
        }

        // set preview size and make any resize, rotate or
        // reformatting changes here

        // 設置改變完後，重新開始預覽
        try {
            mCamera.setPreviewDisplay(mHolder);
            mCamera.startPreview();

        } catch (Exception e){
            Log.d(TAG, "Error starting camera preview: " + e.getMessage());
        }
    }
}
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