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Android?中TextureView和SurfaceView的屬性方法及示例說明_Android

作者：??芝麻粒兒???? ? 更新時間： 2022-08-14 編程語言

實踐過程

SurfaceView屬性和方法

  • surfaceCreated(@NonNull SurfaceHolder holder)：surface創建時回調
  • surfaceDestroyed(@NonNull SurfaceHolder holder)：surface銷毀時回調
  • surfaceChanged(@NonNull SurfaceHolder holder, int format, int width, int height)：surface發生變化時回調
  • SurfaceHolder.addCallback(context)：添加回調，也就是上面三個方法
  • lockCanvas()：獲取Canvas對象并鎖定畫布，調用Canvas進行繪圖，和unlockCanvasAndPost是依次成對出現。
  • unlockCanvasAndPost()：結束鎖定畫布，并且提交改變。和lockCanvas是依次成對出現。

TextureView屬性和方法

  • getSurfaceTexture（）：此方法返回此視圖使用的 SurfaceTexture。
  • getBitmap（整型寬度，整型高度）：此方法返回返回關聯表面紋理內容的位圖表示形式。
  • getTransform（Matrix transform）：此方法返回與此紋理視圖關聯的轉換。
  • isOpaque（）：此方法指示此視圖是否不透明。
  • lockCanvas（）：此方法開始編輯曲面中的像素。
  • setOpaque（boolean opaque）：此方法指示此紋理視圖的內容是否不透明。
  • setTransform（Matrix transform）：此方法將轉換設置為與此紋理視圖關聯。
  • unlockCanvasAndPost（Canvas canvas）：此方法完成對曲面中像素的編輯。
  • onSurfaceTextureAvailable(SurfaceTexture arg0, int arg1, int arg2)：創建的監聽，前提開啟硬件加速
  • onSurfaceTextureDestroyed(SurfaceTexture arg0)：銷毀的監聽
  • onSurfaceTextureSizeChanged(SurfaceTexture arg0, int arg1,int arg2)：變化的監聽
  • onSurfaceTextureUpdated(SurfaceTexture arg0)：更新的監聽

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轉方向
            mTextureView.setAlpha(1.0f);
            mTextureView.setRotation(90.0f);
??????? } catch (IOException ioe) {
??????????? // 異常處理
??????? }
??? }
??? 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版本自定義

public class ECGSurfaceViewJava extends SurfaceView implements SurfaceHolder.Callback {
??? //簡單模擬一下數據
??? public List<Integer> ecgDatas = new ArrayList<>();
??? //矩陣? 畫布 畫筆 顏色
??? private Rect rect;
??? private Canvas mCanvas;
??? private Paint mPaint;? //畫波形的畫筆
??? private String line_color = "#01FC00";? //畫筆默認是綠色的
??? private int wave_speed = 30;//定義波速：30mm/s
??? private int sleepTime = 8;//每次鎖屏的時間間距，單位ms 連線的時間長度，，如果大則會卡頓效果
??? 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) {
?????????????? //在這獲取改view的寬度? 如果mStartX超過則歸位 這樣實現反復從頭畫，我這800只是簡單表示下效果
??????????????? if (mStartX > 800) {
??????????????????? mStartX = 0;
??????????????? }
??????????????? //繪制區域不斷向右變化
??????????????? rect.set(mStartX, 0, mStartX + 16, 300);
????????? ??????mCanvas = surfaceHolder.lockCanvas(rect);? //提交繪制區域
??????????????? if (mCanvas == null) return;
??????????????? //很重要，如果反復從頭繪制，會覆蓋上一次的繪制
??????????????? mCanvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
??????????????? if (ecgDatas.size() > 0) {
??????????????????? mCanvas.drawLine(mStartX, mStartY, mStartX + 16, ecgDatas.get(0), mPaint);
??????????????????? //這個點的重點是下一個點的起點
??????????????????? mStartX = mStartX + 16;
??????????????????? mStartY = ecgDatas.get(0);
??????????????????? ecgDatas.remove(0);
??????????????? } else {
??????????????????? initData();
??????????????? }
??????????????? surfaceHolder.unlockCanvasAndPost(mCanvas);??? //這種方式把上次繪制的遮蓋了 因此出現了斷點
??????????? }
??????? }
??? };
??? public ECGSurfaceViewJava(Context context, AttributeSet attrs) {
??????? super(context, attrs);
??????? this.surfaceHolder = this.getHolder();//獲取holder
??????? this.surfaceHolder.addCallback(this);
??????? rect = new Rect();? //繪制矩陣內
??????? mPaint = new Paint();
??????? mPaint.setColor(Color.parseColor(line_color));?? //畫筆顏色
??????? mPaint.setAntiAlias(true);?? //抗鋸齒
??????? 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版本自定義

class ECGSurfaceViewKotlin(context: Context?, attrs: AttributeSet?) : SurfaceView(context, attrs), SurfaceHolder.Callback {
??? //簡單模擬一下數據
??? var ecgDatas: MutableList<Int> = ArrayList()
??? //矩陣? 畫布 畫筆 顏色
??? private var rect: Rect? = null
??? private var mCanvas: Canvas? = null
??? //畫波形的畫筆
??? private var mPaint: Paint? = null
??? private val line_color = "#01FC00" //畫筆默認是綠色的
??? private val wave_speed = 30 //定義波速：30mm/s
??? private val sleepTime = 8 //每次鎖屏的時間間距，單位ms 連線的時間長度，，如果大則會卡頓效果
??? var surfaceHolder: SurfaceHolder? = null
??? private var isCanRun = true
??? private var mStartX = 0
??? private var mStartY = 0
?
??? private val drawRunnable = Runnable {
??????? while (isCanRun) {
?????????? //在這獲取改view的寬度? 如果mStartX超過則歸位 這樣實現反復從頭畫，我這800只是簡單表示下效果
??????????? if (mStartX > 800) {
??????????????? mStartX = 0
??????????? }
??????????? //繪制區域不斷向右變化
??????????? rect!![mStartX, 0, mStartX + 16] = 300
??????????? mCanvas = surfaceHolder!!.lockCanvas(rect) //提交繪制區域
??????????? if (mCanvas == null) return@Runnable
??????????? //很重要，如果反復從頭繪制，會覆蓋上一次的繪制
??????????? mCanvas!!.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR)
??????????? if (ecgDatas.size > 0) {
??????????????? mCanvas!!.drawLine(mStartX.toFloat(), mStartY.toFloat(), (mStartX + 16).toFloat(), ecgDatas[0].toFloat(), mPaint)
??????????????? //這個點的重點是下一個點的起點
??????????????? mStartX = mStartX + 16
??????????????? mStartY = ecgDatas[0]
??????????????? ecgDatas.removeAt(0)
??????????? } else {
??????????????? initData()
??????????? }
??????????? surfaceHolder!!.unlockCanvasAndPost(mCanvas!!) //這種方式把上次繪制的遮蓋了 因此出現了斷點
??????? }
??? }
??? init {
??????? surfaceHolder = this.holder //獲取holder
??????? surfaceHolder!!.addCallback(this)
??????? rect = Rect() //繪制矩陣內
??????? mPaint = Paint()
??????? mPaint!!.setColor(Color.parseColor(line_color)) //畫筆顏色
??????? mPaint!!.setAntiAlias(true) //抗鋸齒
?????? ?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" />

上面小空只是簡單寫了下示例，如果是畫心電圖其實還有更多的邏輯，比如多個心電圖同步，比如超出屏幕后回到起始位置，比如實時更新心電圖數據，再比如心電圖速度控制等等。

而且上面心電圖示例是從左到右的，還有可能從上到下，從右到左的等等，更多功能就交給大佬們去開發了。

原文鏈接：https://juejin.cn/post/7111615602845810718

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