AudioRecorder功能

AudioRecorder功能
AudioRecorder這個物件可以設定錄音的品質(頻率、取樣數、聲道)
但是錄出來的資料是原始音頻檔(PCM)
後續還要加Header將其轉換成可播放的格式，例如WAV
下面是使用AudioRecorder做錄音的範例
在範例中，AudioRecorder需要放在另一個線程(Thread)執行
    // 按鈕操作
    public void onClick(View v) {
        // Press start record
        if (v.getId() == R.id.recStart) {
        isRecording = true;
            thread = new Thread(new Runnable() {
                public void run() {
                    record();
                }
            });
            thread.start();
        }
        // Press stop record        else if (v.getId() == R.id.recStop) {
        isRecording = false;
        // 可以用"thread.join()"讓thread進入blocked狀態，目前直接在結束的地方寫"thread.stop();"
        // try {
        //     thread.join();
        // } catch (InterruptedExpection e) { }
        }
    }

    private void record() {
        pcmFile = new File(myDataPath.getAbsolutePath() + "/record.pcm");
        // Delete any previous recording.
        if (pcmFile.exists())
            pcmFile.delete();
        // Create the new file.
        try {
            pcmFile.createNewFile();
        } catch (IOException e) {
            throw new IllegalStateException("Failed to create " + pcmFile.toString());
        }
        // Start record pcm data        try {
            // Create a DataOuputStream to write the audio data into the saved file.            OutputStream os = new FileOutputStream(pcmFile);
            BufferedOutputStream bos = new BufferedOutputStream(os);
            DataOutputStream dos = new DataOutputStream(bos);  
            // Create a new AudioRecord object to record the audio.
            int bufferSize =
            AudioRecord.getMinBufferSize(
                sampleRateInHz,
                AudioFormat.CHANNEL_IN_MONO,
                AudioFormat.ENCODING_PCM_16BIT);
  
            AudioRecord audioRecord =
                new AudioRecord(
                    MediaRecorder.AudioSource.MIC,
                    sampleRateInHz,
                    AudioFormat.CHANNEL_IN_MONO,
                    AudioFormat.ENCODING_PCM_16BIT,
                    bufferSize);
            byte[] buffer = new byte[bufferSize];
            audioRecord.startRecording();
            while (isRecording) {
                int bufferReadResult = audioRecord.read(buffer, 0, bufferSize);
                for (int i = 0; i < bufferReadResult; i++)
                    dos.write(buffer[i]);
            }  
            // filler, data size need can %8 = 0            if (dos.size()%8  != 0) {
                int filler = 0;
                filler = 8 - (dos.size()%8);
                for (int i = 0 ; i < filler ; i++) {
                    dos.writeByte(0);
                }
            }
  
            // stop record and close the file.            audioRecord.stop();
            dos.close();
        } catch (Throwable t) { }
        // stop thread, this method may be not great, we can use the "thread.join( )" method
        thread.stop();
    }

FingerPaint功能

FingerPaint功能
下面為一繪圖的範例
    public class Project1 extends Activity {
        private Bitmap  mBitmap;
        private MyView mView;

        public void onCreate (Bundle bundle) {
            super.onCreate(bundle);
            // remove the title, and display "full screen"
            this.requestWindowFeature(Window.FEATURE_NO_TITLE);
            this.getWindow().setFlags(
                WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
            // get the windows resolution, for bitmap use
            DisplayMetrics dm = new DisplayMetrics();
            getWindowManager().getDefaultDisplay().getMetrics(dm);
            // create a new bitmap for paint
            mBitmap = Bitmap.createBitmap(dm.widthPixels, dm.heightPixels, Bitmap.Config.ARGB_8888);
            // use "MyView" class, this is define by author
            mView = new MyView(this);
            setContentView(mView);
        }

        private class MyView extends View {
            private Canvas mCanvas;
            private Path mPath;
            private Paint mBitmapPaint;
            private Paint mPaint;

            private float new_x, new_y;
            private float old_x, old_y;

            public MyView(Context context) {
                super(context);
                // create and initial object
                mCanvas = new Canvas(mBitmap);
                mPath = new Path();
                mBitmapPaint = new Paint(Paint.DITHER_FLAG);
        
                mPaint = new Paint();
                // make paint more smooth
                mPaint.setAntiAlias(true);
                mPaint.setDither(true);
                // (1.FILL 2.FILL_AND_STROKE 3.STROKE)
                mPaint.setStyle(Paint.Style.STROKE);
                // (1.BEVEL 2.MITER 3.ROUND) default is MITER
                mPaint.setStrokeJoin(Paint.Join.ROUND);
                // (1.BUTT 2.ROUND 3.SQUARE) default is BUIT
                mPaint.setStrokeCap(Paint.Cap.ROUND);
                // if set "0", will be a line
                mPaint.setStrokeWidth(12);
                mPaint.setColor(Color.GREEN);
            }
    
            protected void onDraw(Canvas canvas) {
                // set background color
                canvas.drawColor(Color.WHITE);
                // draw the specified bitmap
                canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
                // the path will be filled or framed based on the Style in the paint
                canvas.drawPath(mPath, mPaint);
            }
 
            public boolean onTouchEvent(MotionEvent event) {
                new_x = event.getX();
                new_y = event.getY();
      
                if (event.getAction() == MotionEvent.ACTION_DOWN) {
                    // save the previous path, then reset the path
                    mPath.reset();
                    // start position
                    mPath.moveTo(new_x, new_y);
                    old_x = new_x;
                    old_y = new_y;
                }
                else if (event.getAction() == MotionEvent.ACTION_MOVE) {
                    float dx = Math.abs(new_x - old_x);
                    float dy = Math.abs(new_y - old_y);
          
                    if (dx >= 4 || dy >= 4) {
                        // set path from (old_x, old_y) to ((new_x + old_x)/2, (new_y + old_y)/2)
                        mPath.quadTo(old_x, old_y, (new_x + old_x)/2, (new_y + old_y)/2);
                        old_x = new_x;
                        old_y = new_y;
                    }
                }
                else if (event.getAction() == MotionEvent.ACTION_UP) {
                    // unknown, this line like no used
                    mPath.lineTo(old_x, old_y);
                    // paint the path when "ACTION_UP"
                    mCanvas.drawPath(mPath, mPaint);
                    // save the paint
                    mPath.reset();
                }
      
                // update the paint, it will recall the onDraw function
                invalidate();
                return true;
            }
        }
    }

WiFi功能

WiFi功能
這邊簡單介紹WIFI開關的功能
    public class wifi extends Activity implements OnCheckedChangeListener{
        private WifiManager wifiManager;
        private WifiInfo wifiInfo;
        private CheckBox chkOpenCloseWifiBox;
        private List<WifiConfiguration> wifiConfigurations;

        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.display);
            // 獲得WifiManager對象
            wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
       
            // 獲得連接訊息
            wifiInfo = wifiManager.getConnectionInfo();
            chkOpenCloseWifiBox = (CheckBox) findViewById(R.id.chkOpenCloseWifi);
            TextView tvWifiConfigurations = (TextView) findViewById(R.id.tvWifiConfigurations);
            TextView tvWifiInfo = (TextView) findViewById(R.id.tvWifiInfo);       
            chkOpenCloseWifiBox.setOnCheckedChangeListener(this);
            // 根據目前WiFi狀態設置輸出訊息
            if (wifiManager.isWifiEnabled()) {
                chkOpenCloseWifiBox.setText("Wifi opened");
                chkOpenCloseWifiBox.setChecked(true);
            }
            else {
                chkOpenCloseWifiBox.setText("Wifi closed");
                chkOpenCloseWifiBox.setChecked(false);
            }
       
            // 輸出WIFI訊息
            StringBuffer sb = new StringBuffer();
            sb.append("Wifi Info\n");
            sb.append("MAC Address：" + wifiInfo.getMacAddress() + "\n");
            sb.append("SSID：" + wifiInfo.getSSID() + "\n");
            sb.append("IP Address（int）：" + wifiInfo.getIpAddress() + "\n");
            sb.append("IP Address（Hex）：" + Integer.toHexString(wifiInfo.getIpAddress()) + "\n");
            sb.append("IP Address：" + ipIntToString(wifiInfo.getIpAddress()) + "\n");
            sb.append("Network ID：" + wifiInfo.getNetworkId() + "\n");
            sb.append("Network Speed：" + Integer.toString(wifiInfo.getLinkSpeed()) + "\n");
            sb.append("Signal Strength：" + Integer.toString(wifiInfo.getRssi()) + "\n");
            tvWifiInfo.setText(sb.toString());
            // 得到配置好的網路
            wifiConfigurations = wifiManager.getConfiguredNetworks();
            tvWifiConfigurations.setText("Had connected wifi\n");
            for (WifiConfiguration wifiConfiguration : wifiConfigurations) {
                tvWifiConfigurations.setText(tvWifiConfigurations.getText() + wifiConfiguration.SSID + "\n");
            }
        }

        // 將int型態的IP轉換成文字型態
        private String ipIntToString(int ip) {
            try {
                byte[] bytes = new byte[4];
                bytes[0] = (byte) (0xff & ip);
                bytes[1] = (byte) ((0xff00 & ip) >> 8);
                bytes[2] = (byte) ((0xff0000 & ip) >> 16);
                bytes[3] = (byte) ((0xff000000 & ip) >> 24);
                return Inet4Address.getByAddress(bytes).getHostAddress();
            }
            catch (Exception e) {
                return "";
            }
        }
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            // 當選中複選框時打開WiFi
            if (isChecked) {
                wifiManager.setWifiEnabled(true);
                chkOpenCloseWifiBox.setText("Wifi opened");
            }
            // 當取消複選框時關閉WiFi
            else {
                wifiManager.setWifiEnabled(false);
                chkOpenCloseWifiBox.setText("Wifi closed");
            }
        }
    }

SD card read/write功能

SD card read/write功能
功能：讀寫SD card

AndroidManifest.xml
    加入權限"android.permission.WRITE_EXTERNAL_STORAGE"

 Xxx.java
    // Write
    private writeToSdCard() {
        File vSDCard= null;
        try {
            // 獲得外部外接裝置位置
            vSDCard= Environment.getExternalStorageDirectory();
 
            // vSDCard.getParent() - "/" ; vSDCard.getName() - "sdcard"
            FileWriter vFile = new FileWriter(vSDCard.getParent() + vSDCard.getName() + "/Log.txt", true);
            // 使用這種方式有可能會得到錯誤的路徑，所以改用下面的方式
            // vSDCard.getAbsolutePath() - 擷取目前位置路徑
            FileWriter vFile = new FileWriter(vSDCard.getAbsolutePath() + "/Log.txt", true);
    
            // write the data to file
            vFile.append("," + status + "," + level + "," + "\n");
            vFile.close();
        }
        catch (Exception e) {
        }
    }

    // Read
    private void readFromSdCard() {
        File vSDCard= null;
        try {
            // 獲得外部外接裝置位置
            vSDCard= Environment.getExternalStorageDirectory();
 
            // read data form sd card file
            FileReader vFile = new FileReader( vSDCard.getAbsolutePath() + "/sd_test.txt" );
            StringBuffer sb = new StringBuffer();
            int c;
            // if value = "-1", it mean the end of the file
            while ((c = vFile.read()) != -1) {
                sb.append((char) c);
            }
            vFile.close();
        }
        catch (Exception e) {
        }
    }

設定Brightness功能

設定Brightness功能
在提及設定Brightness功能之前要先介紹一下目前Android設定Brightness的方式。
目前Android設定Brightness的方式大致上分為二種：
1. 調整目前AP的亮度，離開AP會返回系統設定亮度。
2. 調整系統亮度，但是設定值要在亮度有被修改時才會更新。
    例如：進入設定亮度頁面，再離開，或修改AP亮度。

若要在AP裡設定系統亮度，則需要使用到上述二個部分。
相關程式碼如下：

AndroidManifest.xml
    加入權限"android.permission.WRITE_SETTINGS"

Xxx.java
// 可以利用SeekBar物件當作設定值的輸入
// 修改系統亮度設定
    // 先將亮度設定模式調整為手動
    Settings.System.putInt(
        getContentResolver(),
        Settings.System.SCREEN_BRIGHTNESS_MODE,
        Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
    // 修改系統亮度設定 (setting rage : 0~255)
    Settings.System.putInt(getContentResolver(),Settings.System.SCREEN_BRIGHTNESS,value);

    // 修改目前視窗亮度 (setting rage : 0.0~1.0)
    WindowManager.LayoutParams lp = getWindow().getAttributes();
    lp.screenBrightness = value/255f;
    getWindow().setAttributes(lp);

*當設定值0時，會造成Android系統將整個螢幕關閉的問題。

Wake up lock功能

Wake up lock功能
功能：程式執行時，鎖定在Wake up狀態

AndroidManifest.xml
Add "android.permission.WAKE_LOCK" user permission

    private PowerManager.WakeLock wl;

    // 利用PowerManager取得service，設定wake up狀態
    public void onCreate(Bundle savedInstanceState) {
        .............................
        PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
        wl = pm.newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK, "My Tag");
        wl.acquire();
    }

    // 離開時，釋放控制權
    protected void onDestroy() {
        super.onDestroy();
        wl.release();
    }