画圆拖动0630

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.Rect;

import android.support.annotation.Nullable;

import android.util.AttributeSet;

import android.view.MotionEvent;

import android.view.View;

/**

* Created by muhanxi on 17/6/6.

*/

public class CircleView extends View {

Paint paint;

private float x = 100;

private float y = 100;

Rect rect = new Rect();

public CircleView(Context context) {

super(context);

}

public CircleView(Context context, @Nullable AttributeSet attrs) {

super(context, attrs);

paint = new Paint();

paint.setColor(Color.RED);

paint.setAntiAlias(true);

}

public CircleView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {

super(context, attrs, defStyleAttr);

}

public CircleView(Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {

super(context, attrs, defStyleAttr, defStyleRes);

}

@Override

protected void onDraw(Canvas canvas) {

super.onDraw(canvas);

canvas.drawCircle(x,y,100,paint);

rect.set((int)(x-100),(int) (y-100),(int)( x+100),(int)(y+100));

}

@Override

public boolean onTouchEvent(MotionEvent event) {

switch (event.getAction()){

case MotionEvent.ACTION_DOWN:

break;

case MotionEvent.ACTION_MOVE:

float x1 = event.getX() ;

float y1 = event.getY();

if (x1 > rect.left && x1 < rect.right && y1 > rect.top && y1 < rect.bottom) {

//主线程调用刷新

x = event.getX();

y = event.getY();

invalidate();

//子线程 调用刷新

// postInvalidate();

}

break;

case MotionEvent.ACTION_UP:

break;

case MotionEvent.ACTION_POINTER_DOWN:

System.out.println("event = ACTION_POINTER_DOWN " + event);

break;

}

return true;

}

}