public class MainActivity extends Activity implements SurfaceTextureListener{
private Camera mCamera;
private TextureView [mTextureView]();
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mTextureView = new TextureView(this);
mTextureView.setSurfaceTextureListener(this);
setContentView(mTextureView);
}
public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
mCamera = Camera.open();
try {
mCamera.setPreviewTexture(surface);
mCamera.startPreview();
//可以修改透明度和旋转方向
mTextureView.setAlpha(1.0f);
mTextureView.setRotation(90.0f);
} catch (IOException ioe) {
// 异常处理
}
}
public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {
}
public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
mCamera.stopPreview();
mCamera.release();
return true;
}
public void onSurfaceTextureUpdated(SurfaceTexture surface) {
}
}
Java版本自定义
public class ECGSurfaceViewJava extends SurfaceView implements SurfaceHolder.Callback {
//简单模拟一下数据
public List<Integer> ecgDatas = new ArrayList<>();
//矩阵 画布 画笔 颜色
private Rect rect;
private Canvas mCanvas;
private Paint mPaint; //画波形的画笔
private String line_color = "#01FC00"; //画笔默认是绿色的
private int wave_speed = 30;//定义波速：30mm/s
private int sleepTime = 8;//每次锁屏的时间间距，单位ms 连线的时间长度，，如果大则会卡顿效果
private SurfaceHolder surfaceHolder;
private boolean isCanRun = true;
private int mStartX = 0;
private int mStartY = 0;
private Runnable drawRunnable = new Runnable() {
@Override
public void run() {
while (isCanRun) {
//在这获取改view的宽度 如果mStartX超过则归位 这样实现反复从头画，我这800只是简单表示下效果
if (mStartX > 800) {
mStartX = 0;
}
//绘制区域不断向右变化
rect.set(mStartX, 0, mStartX + 16, 300);
mCanvas = surfaceHolder.lockCanvas(rect); //提交绘制区域
if (mCanvas == null) return;
//很重要，如果反复从头绘制，会覆盖上一次的绘制
mCanvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
if (ecgDatas.size() > 0) {
mCanvas.drawLine(mStartX, mStartY, mStartX + 16, ecgDatas.get(0), mPaint);
//这个点的重点是下一个点的起点
mStartX = mStartX + 16;
mStartY = ecgDatas.get(0);
ecgDatas.remove(0);
} else {
initData();
}
surfaceHolder.unlockCanvasAndPost(mCanvas); //这种方式把上次绘制的遮盖了 因此出现了断点
}
}
};
public ECGSurfaceViewJava(Context context, AttributeSet attrs) {
super(context, attrs);
this.surfaceHolder = this.getHolder();//获取holder
this.surfaceHolder.addCallback(this);
rect = new Rect(); //绘制矩阵内
mPaint = new Paint();
mPaint.setColor(Color.parseColor(line_color)); //画笔颜色
mPaint.setAntiAlias(true); //抗锯齿
mPaint.setStrokeWidth(2);
initData();
}
private void initData() {
ecgDatas.clear();
for (int i = 0; i < 200; i++) {
ecgDatas.add((int) (Math.random() * 200));
}
mStartY = ecgDatas.get(0);
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
new Thread(drawRunnable).start();
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
isCanRun = false;
}
}
Kotlin版本自定义
class ECGSurfaceViewKotlin(context: Context?, attrs: AttributeSet?) : SurfaceView(context, attrs), SurfaceHolder.Callback {
//简单模拟一下数据
var ecgDatas: MutableList<Int> = ArrayList()
//矩阵 画布 画笔 颜色
private var rect: Rect? = null
private var mCanvas: Canvas? = null
//画波形的画笔
private var mPaint: Paint? = null
private val line_color = "#01FC00" //画笔默认是绿色的
private val wave_speed = 30 //定义波速：30mm/s
private val sleepTime = 8 //每次锁屏的时间间距，单位ms 连线的时间长度，，如果大则会卡顿效果
var surfaceHolder: SurfaceHolder? = null
private var isCanRun = true
private var mStartX = 0
private var mStartY = 0
private val drawRunnable = Runnable {
while (isCanRun) {
//在这获取改view的宽度 如果mStartX超过则归位 这样实现反复从头画，我这800只是简单表示下效果
if (mStartX > 800) {
mStartX = 0
}
//绘制区域不断向右变化
rect!![mStartX, 0, mStartX + 16] = 300
mCanvas = surfaceHolder!!.lockCanvas(rect) //提交绘制区域
if (mCanvas == null) return@Runnable
//很重要，如果反复从头绘制，会覆盖上一次的绘制
mCanvas!!.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR)
if (ecgDatas.size > 0) {
mCanvas!!.drawLine(mStartX.toFloat(), mStartY.toFloat(), (mStartX + 16).toFloat(), ecgDatas[0].toFloat(), mPaint)
//这个点的重点是下一个点的起点
mStartX = mStartX + 16
mStartY = ecgDatas[0]
ecgDatas.removeAt(0)
} else {
initData()
}
surfaceHolder!!.unlockCanvasAndPost(mCanvas!!) //这种方式把上次绘制的遮盖了 因此出现了断点
}
}
init {
surfaceHolder = this.holder //获取holder
surfaceHolder!!.addCallback(this)
rect = Rect() //绘制矩阵内
mPaint = Paint()
mPaint!!.setColor(Color.parseColor(line_color)) //画笔颜色
mPaint!!.setAntiAlias(true) //抗锯齿
mPaint!!.setStrokeWidth(2f)
initData()
}
private fun initData() {
ecgDatas.clear()
for (i in 0..199) {
ecgDatas.add((Math.random() * 200).toInt())
}
mStartY = ecgDatas[0]
}
override fun surfaceCreated(holder: SurfaceHolder?) {
Thread(drawRunnable).start()
}
override fun surfaceChanged(holder: SurfaceHolder?, format: Int, width: Int, height: Int) {
}
override fun surfaceDestroyed(holder: SurfaceHolder?) {
isCanRun = false
}
}布局直接使用即可：
<cn.appstudy.customView.ECGSurfaceViewJava
android:layout_width="match_parent"
android:layout_height="200dp"/>
<cn.appstudy.customView.ECGSurfaceViewKotlin
android:layout_width="match_parent"
android:layout_height="200dp"
android:layout_marginTop="220dp" />
上面小空只是简单写了下示例，如果是画心电图其实还有更多的逻辑，比如多个心电图同步，比如超出屏幕后回到起始位置，比如实时更新心电图数据，再比如心电图速度控制等等。
而且上面心电图示例是从左到右的，还有可能从上到下，从右到左的等等，更多功能就交给大佬们去开发了。
