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继承我的代码，用手指画线绘制圆。我想知道如何查找线条的长度，并想要绘制具有半径线长度的圆。如何在Android Java中查找绘制线的长度？
我该怎么做？
和在哪里，就把这行？
circlePath.addCircle(mX, mY, "line's length", Path.Direction.CW);
public class MainActivity extends Activity {
/** Called when the activity is first created. */
Paint mPaint;
float Mx1,My1;
float x,y;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// setContentView(R.layout.main);
MyView view1 =new MyView(this);
view1.setBackgroundResource(R.color.colorPrimary);
setContentView(view1);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(Color.BLACK);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(10);
}
public class MyView extends View {
private static final float MINP = 0.25f;
private static final float MAXP = 0.75f;
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
private Paint circlePaint;
private Path circlePath;
public MyView(Context c) {
super(c);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
circlePaint = new Paint();
circlePath = new Path();
circlePaint.setAntiAlias(true);
circlePaint.setColor(Color.BLUE);
circlePaint.setStyle(Paint.Style.STROKE);
circlePaint.setStrokeJoin(Paint.Join.MITER);
circlePaint.setStrokeWidth(8f);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.WHITE);
//canvas.drawLine(mX, mY, Mx1, My1, mPaint);
//canvas.drawLine(mX, mY, x, y, mPaint);
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
canvas.drawPath(circlePath, circlePaint);
}
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
//mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
mX = x;
mY = y;
}
//circlePath.reset();
//circlePath.addCircle(mX, mY, Math.abs(mX - mY), Path.Direction.CW);
}
private void touch_up() {
mPath.lineTo(mX, mY);
//circlePath.reset();
// commit the path to our offscreen
mCanvas.drawPath(mPath, mPaint);
// kill this so we don't double draw
mPath.reset();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
circlePath.addCircle(mX, mY, x, Path.Direction.CW);
invalidate();
break;
case MotionEvent.ACTION_UP:
touch_up();
//Mx1=(int) event.getX();
//My1= (int) event.getY();
invalidate();
break;
}
return true;
}
}
}