Android：使用onDraw和onTouchEvent绘制线条渲染速度慢

我尝试使用ontouch方法和onDraw方法绘制四条线，如下所示：

 @Override
       protected void onDraw(Canvas canvas) {
        initPoints();
        path.reset();
        path.addCircle(topLeftPoint.x,topLeftPoint.y, 16f,       
       Path.Direction.CW);
        canvas.drawLines(points, paint);

        path.addCircle(middleTopPoint.x, middleTopPoint.y, 16f, Path.Direction.CW);
        path.addCircle(topRightPoint.x, topRightPoint.y, 16f, Path.Direction.CW);

//      canvas.drawLine(topRightPoint.x, topRightPoint.y, bottomRightPoint.x, bottomRightPoint.y, paint);
        path.addCircle(bottomRightPoint.x, bottomRightPoint.y, 16f, Path.Direction.CW);

        path.addCircle(middleRightPoint.x, middleRightPoint.y, 16f, Path.Direction.CW);
//      canvas.drawLine(bottomRightPoint.x, bottomRightPoint.y, bottomLeftPoint.x, bottomLeftPoint.y, paint);
        path.addCircle(bottomLeftPoint.x, bottomLeftPoint.y, 16f, Path.Direction.CW);
        path.addCircle(middleBottomPoint.x, middleBottomPoint.y, 16f, Path.Direction.CW);

//      canvas.drawLine(bottomLeftPoint.x, bottomLeftPoint.y, topLeftPoint.x, topLeftPoint.y, paint);
        path.addCircle(topRightPoint.x, topRightPoint.y, 16f, Path.Direction.CW);
        path.addCircle(middleLeftPoint.x, middleLeftPoint.y, 16f, Path.Direction.CW);
        path.close();
        canvas.drawPath(path, paint);
            }

    @Override
    public boolean onTouchEvent(final MotionEvent event) {

        int action = event.getActionMasked();

        if (event.getAction() == MotionEvent.ACTION_DOWN ||
                event.getAction() == MotionEvent.ACTION_MOVE
                || event.getAction() == MotionEvent.ACTION_UP) {

            float xCoordinate = 16;
            float yCoordinate = 16;

            if (event.getX() < 16) {
                xCoordinate = 16;
            } else if (event.getX() > getWidth() - 16) {
                xCoordinate = getWidth() - 16;
            } else {
                xCoordinate = event.getX();
            }

            if (event.getY() < 16) {
                yCoordinate = 16;
            } else if (event.getY() > getHeight() - 16) {
                yCoordinate = getHeight() - 16;
            } else {
                yCoordinate = event.getY();
            }
            if (isInsideTopLeft(event.getX(), event.getY())) {
                topLeftPoint.set(xCoordinate, yCoordinate);

                middleTopPoint.set((topRightPoint.x + topLeftPoint.x) / 2,
                        (topRightPoint.y + topLeftPoint.y) / 2);
                middleLeftPoint.set((bottomLeftPoint.x + topLeftPoint.x) / 2,
                        (bottomLeftPoint.y + topLeftPoint.y) / 2);
                invalidate();
                return true;
            } else if (isInsideTopRight(event.getX(), event.getY())) {
                topRightPoint.set(xCoordinate, yCoordinate);

                middleTopPoint.set((topRightPoint.x + topLeftPoint.x) / 2,
                        (topRightPoint.y + topLeftPoint.y) / 2);
                middleRightPoint.set((bottomRightPoint.x + topRightPoint.x) / 2,
                        (bottomRightPoint.y + topRightPoint.y) / 2);
                invalidate();
                return true;
            } else if (isInsideBottomRight(event.getX(), event.getY())) {
                bottomRightPoint.set(xCoordinate, yCoordinate);

                middleBottomPoint.set((bottomLeftPoint.x + bottomRightPoint.x) / 2,
                        (bottomLeftPoint.y + bottomRightPoint.y) / 2);
                middleRightPoint.set((bottomRightPoint.x + topRightPoint.x) / 2,
                        (bottomRightPoint.y + topRightPoint.y) / 2);
                invalidate();
                return true;
            } else if (isInsideBottomLeft(event.getX(), event.getY())) {
                bottomLeftPoint.set(xCoordinate, yCoordinate);

                middleBottomPoint.set((bottomLeftPoint.x + bottomRightPoint.x) / 2,
                        (bottomLeftPoint.y + bottomRightPoint.y) / 2);
                middleLeftPoint.set((bottomLeftPoint.x + topLeftPoint.x) / 2,
                        (bottomLeftPoint.y + topLeftPoint.y) / 2);
                invalidate();
                return true;
            } 
        }

        return super.onTouchEvent(event);
    }   

@覆盖
受保护的void onDraw（画布）{
initPoints（）；
path.reset（）；
path.addCircle（topLeftPoint.x，topLeftPoint.y，16f，
路径。方向。CW）；
帆布。抽绳（点、油漆）；
添加圆（middletopoint.x，middletopoint.y，16f，path.Direction.CW）；
添加圆（topRightPoint.x，topRightPoint.y，16f，path.Direction.CW）；
//画布.抽绳（topRightPoint.x，topRightPoint.y，bottomRightPoint.x，bottomRightPoint.y，绘制）；
添加圆（bottomRightPoint.x，bottomRightPoint.y，16f，path.Direction.CW）；
添加圆（middleRightPoint.x，middleRightPoint.y，16f，path.Direction.CW）；
//画布.抽绳（bottomRightPoint.x，bottomRightPoint.y，bottomLeftPoint.x，bottomLeftPoint.y，绘制）；
addCircle（bottomLeftPoint.x，bottomLeftPoint.y，16f，path.Direction.CW）；
添加圆（中间点x，中间点y，16f，路径方向CW）；
//画布绘制线（bottomLeftPoint.x，bottomLeftPoint.y，topLeftPoint.x，topLeftPoint.y，绘制）；
添加圆（topRightPoint.x，topRightPoint.y，16f，path.Direction.CW）；
添加圆（middleftpoint.x，middleftpoint.y，16f，path.Direction.CW）；
path.close（）；
画布.绘制路径（路径，绘制）；
}
@凌驾
公共布尔onTouchEvent（最终运动事件）{
int action=event.getActionMasked（）；
如果（event.getAction（）==MotionEvent.ACTION\u向下||
event.getAction（）==MotionEvent.ACTION\u MOVE
||event.getAction（）==MotionEvent.ACTION\u UP）{
浮点数xCoordinate=16；
浮动yCoordinate=16；
if（event.getX（）<16）{
xCoordinate=16；
}else if（event.getX（）>getWidth（）-16）{
xCoordinate=getWidth（）-16；
}否则{
xCoordinate=event.getX（）；
}
if（event.getY（）<16）{
yCoordinate=16；
}else if（event.getY（）>getHeight（）-16）{
yCoordinate=getHeight（）-16；
}否则{
yCoordinate=event.getY（）；
}
if（isInsideTopLeft（event.getX（），event.getY（））{
topLeftPoint.set（xCoordinate，yCoordinate）；
middleTopPoint.set（（topRightPoint.x+topLeftPoint.x）/2，
（右上角点y+左上角点y）/2）；
middleftpoint.set（（bottomLeftPoint.x+topLeftPoint.x）/2，
（底部leftpoint.y+顶部leftpoint.y）/2）；
使无效（）；
返回true；
}else if（isInsideTopRight（event.getX（），event.getY（））{
topRightPoint.set（xCoordinate，yCoordinate）；
middleTopPoint.set（（topRightPoint.x+topLeftPoint.x）/2，
（右上角点y+左上角点y）/2）；
middleRightPoint.set（（bottomRightPoint.x+topRightPoint.x）/2，
（右下角点y+右上角点y）/2）；
使无效（）；
返回true；
}else if（isInsideBottomRight（event.getX（），event.getY（））{
右下角点集（xCoordinate，yccoordinate）；
中间底部点.set（（bottomLeftPoint.x+bottomRightPoint.x）/2，
（bottomLeftPoint.y+bottomRightPoint.y）/2）；
middleRightPoint.set（（bottomRightPoint.x+topRightPoint.x）/2，
（右下角点y+右上角点y）/2）；
使无效（）；
返回true；
}else if（isInsideBottomLeft（event.getX（），event.getY（））{
底部左端点集（xCoordinate，yccoordinate）；
中间底部点.set（（bottomLeftPoint.x+bottomRightPoint.x）/2，
（bottomLeftPoint.y+bottomRightPoint.y）/2）；
middleftpoint.set（（bottomLeftPoint.x+topLeftPoint.x）/2，
（底部leftpoint.y+顶部leftpoint.y）/2）；
使无效（）；
返回true；
} 
}
返回super.onTouchEvent（事件）；
}   

但是当我增加触摸速度时，渲染速度变慢了。 我已经使用了路径和线，但性能的提高仍然很小

我从代码中删除的其他方法，如声明PointF对象和使用默认值启动这些对象

如果有人有任何想法，我将不胜感激

致以最良好的祝愿，

---

AurelianR

如果没有完整的代码，很难检查可能需要改进的地方。 您正在调用initPoints（）并在每次绘制调用时重置路径

如果在触摸事件中考虑以下情况：

if (isInsideTopLeft(event.getX(), event.getY())) {
      // update topLeftPoint, middleTopPoint and middleLeftPoint.
        invalidate();
        return true;
    }

然后在onDraw（）中

只有三个调用更新了rest 6路径更新，可以避免。可以使用postInvalidate（dirtyRect）。

---

如果您添加了完整的代码（以及基本注释），那么我可以通过运行它进行检查。

您的问题与性能无关，而是触摸处理的错误执行。触摸处理概念简介：您的视图获得以下触摸事件的

操作：用户将手指放在视图上时接收（一次性）。总是生成

动作\移动：当用户移动手指时接收（多次）。如果用户不移动手指，则不会生成此事件

动作提示：当用户将手指从您的视线中抬起时收到（一次）。总是生成

向下直到向上完成一个周期的触摸事件，用户可以多次触摸您的视图

您的代码：

if (event.getAction() == MotionEvent.ACTION_DOWN ||
            event.getAction() == MotionEvent.ACTION_MOVE
            || event.getAction() == MotionEvent.ACTION_UP){

    if(isInsideTopLeft()){
    // do something
    // return
    } 
    // do same for other cases also.
}

这样，您每次都在计算案例（isInsideTopLeft（）等），这会导致删除触摸事件（任何案例都不包括该事件）。你呢

if (event.getAction() == MotionEvent.ACTION_DOWN ||
            event.getAction() == MotionEvent.ACTION_MOVE
            || event.getAction() == MotionEvent.ACTION_UP){

    if(isInsideTopLeft()){
    // do something
    // return
    } 
    // do same for other cases also.
}

//create touch lock cases 
private final int TOUCH_STATE_UNLOCKED = 0;
private final int TOUCH_STATE_LOCKED_TOP_LEFT = 1;
private final int TOUCH_STATE_LOCKED_TOP_RIGHT = 2;
private final int TOUCH_STATE_LOCKED_BOTTOM_LEFT = 3;
private final int TOUCH_STATE_LOCKED_BOTTOM_RIGHT = 4;
private final int TOUCH_STATE_LOCKED_MIDDLE_LEFT = 5;
private final int TOUCH_STATE_LOCKED_MIDDLE_BOTTOM = 6;

private int TOUCH_STATE = TOUCH_STATE_UNLOCKED;

 @Override
public boolean onTouchEvent(final MotionEvent event) {

    int action = event.getActionMasked();
    float xCoordinate = 16;
    float yCoordinate = 16;
    int eventX = (int) event.getX();
    int eventY = (int) event.getY();

    if (eventX < 16) {
        xCoordinate = 16;
    } else if (eventX > getWidth() - 16) {
        xCoordinate = getWidth() - 16;
    } else {
        xCoordinate = eventX;
    }

    if (eventY < 16) {
        yCoordinate = 16;
    } else if (eventY > getHeight() - 16) {
        yCoordinate = getHeight() - 16;
    } else {
        yCoordinate = eventY;
    }

    switch (event.getAction() & MotionEvent.ACTION_MASK) {
        /* Touch event handling in brief,  read about touch event handling,

        in ACTION_DOWN lock touch event for a particular point.


         */
        case MotionEvent.ACTION_DOWN:

            // lock touch event for a point . subsequent touch events
            if (isInsideTopLeft(event.getX(), event.getY())) {
                TOUCH_STATE = TOUCH_STATE_LOCKED_TOP_LEFT;
            } else if (isInsideTopRight(event.getX(), event.getY())) {
                TOUCH_STATE = TOUCH_STATE_LOCKED_TOP_RIGHT;
            } else if (isInsideBottomLeft(event.getX(), event.getY())) {
                TOUCH_STATE = TOUCH_STATE_LOCKED_BOTTOM_LEFT;
            } else if (isInsideBottomRight(event.getX(), event.getY())) {
                TOUCH_STATE = TOUCH_STATE_LOCKED_BOTTOM_RIGHT;
            } else if (isInsideMiddleLeft(event.getX(), event.getY())) {
                TOUCH_STATE = TOUCH_STATE_LOCKED_MIDDLE_LEFT;
            } else if (isInsideMiddleBottom(event.getX(), event.getY())) {
                TOUCH_STATE = TOUCH_STATE_LOCKED_MIDDLE_BOTTOM;
            }
            Log.e(TAG, "onTouchEvent: TOUCH_STATE = " + TOUCH_STATE);
            break;

        case MotionEvent.ACTION_MOVE:
// simply check for locked case
            if (TOUCH_STATE == TOUCH_STATE_LOCKED_TOP_LEFT) {
                Log.e(TAG, "onTouchEvent: top left locked");
                topLeftPoint.set(xCoordinate, yCoordinate);

                middleTopPoint.set((topRightPoint.x + topLeftPoint.x) / 2,
                        (topRightPoint.y + topLeftPoint.y) / 2);
                middleLeftPoint.set((bottomLeftPoint.x + topLeftPoint.x) / 2,
                        (bottomLeftPoint.y + topLeftPoint.y) / 2);
                // working fine with full invalidate also.
                invalidate();
            }
            // handle other cases also
            break;

        case MotionEvent.ACTION_UP:
            TOUCH_STATE = TOUCH_STATE_UNLOCKED;  // unlock

    }
    return true;
}