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Android extureView和SurfaceView

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实践过程

SurfaceView属性和方法

TextureView属性和方法

TextureView示例

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) {
    }
}

SurfaceView示例

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。

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