Android自定义View实现雪花特效

package com.ilz.rocketapplication.handaccount.view;
 
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.widget.RelativeLayout;
 
import com.ilz.rocketapplication.handaccount.R;
import com.ilz.rocketapplication.handaccount.bean.SnowBean;
import com.ilz.rocketapplication.handaccount.utils.ColorUtils;
import com.ilz.rocketapplication.handaccount.utils.Tools;
 
import java.util.ArrayList;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;
 
public class SnowView extends RelativeLayout {
// private final String SNOW = "❄";
// private final String SNOW = "☀❆★❉❈❀✿❃❁";
 private final String SNOW = "❄";
 private float vX = 2.5f;//风向 >0 右边飘 <0 左边飘
 private float vY = 5f;//下落速度 <0你的雪花要往上飘呀
 private int snowCount = 50;//雪花个数
 private List<SnowBean> snowBeanList = new ArrayList<>();
 
 private int XB = Tools.getWindowsWidth();
 private int YB = Tools.getWindowsHeight();
 
 private Paint paint = new Paint();
 private Timer timer;
 
 private boolean isStart = false;
 
 public SnowView(Context context) {
  this(context, null);
 }
 
 public SnowView(Context context, AttributeSet attrs) {
  this(context, attrs, 0);
 }
 
 public SnowView(Context context, AttributeSet attrs, int defStyleAttr) {
  super(context, attrs, defStyleAttr);
  initView();
 }
 
 private void initView() {
  paint.setAntiAlias(true);
  initSnowData();
 }
 
 public void start() {
  if (timer == null) {
   timer = new Timer();
  }
  isStart = true;
  timer.schedule(new TimerTask() {
   @Override
   public void run() {
 
    if (!isStart) return;
    for (int i = 0; i < snowBeanList.size(); i++) {
 
     snowBeanList.get(i).setX(snowBeanList.get(i).getX() + vX);
     snowBeanList.get(i).setY(snowBeanList.get(i).getY() + vY);
 
     if (snowBeanList.get(i).getX() < 0 || snowBeanList.get(i).getX() > XB) {
      snowBeanList.get(i).setX(getRandomX());
     }
     if (snowBeanList.get(i).getY() < 0 || snowBeanList.get(i).getY() > YB) {
      snowBeanList.get(i).setY(0f);
     }
    }
 
    postInvalidate();
   }
  }, 0, 15);
 }
 
 public void resume() {
  if (timer == null) {
   start();
  }
  isStart = true;
 }
 
 public void pause(){
  isStart = false;
 }
 
 public void destroy() {
  isStart = false;
  if (snowBeanList != null) {
   snowBeanList.clear();
  }
  invalidate();
  if (timer != null) {
   timer.cancel();
   timer = null;
  }
 }
 
 private void initSnowData() {
  for (int i = 0; i < snowCount; i++) {
   SnowBean bean = new SnowBean();
   bean.setX(getRandomX());
   bean.setY(getRandomY());
   bean.setSize((float) (Math.random() * 50) + 5);
   snowBeanList.add(bean);
  }
 }
 
 private float getRandomX() {
  return (float) (Math.random() * Tools.getWindowsWidth());
 }
 
 private float getRandomY() {
  return (float) (Math.random() * Tools.getWindowsHeight());
 }
 
 
 @Override
 protected void onLayout(boolean changed, int l, int t, int r, int b) {
  super.onLayout(changed, l, t, r, b);
 }
 
 @Override
 protected void onDraw(Canvas canvas) {
  super.onDraw(canvas);
  for (int i = 0; i < snowBeanList.size(); i++) {
   SnowBean bean = snowBeanList.get(i);
   paint.setTextSize(bean.getSize());
   paint.setColor(bean.getColor());
   canvas.drawText(SNOW, bean.getX(), bean.getY(), paint);
  }
 }
 
 
 private GestureDetector detector = new GestureDetector(getContext(),new MyGestureDetector());
 private boolean isPoint = false;
 private long pointTime = 0;
 @Override
 public boolean onTouchEvent(MotionEvent event) {
//  switch (event.getAction()) {
//   case MotionEvent.ACTION_DOWN:
//    pointTime = 0;
//    int pCount = event.getPointerCount();
//    if (pCount >= 2) {
//     isPoint = true;
//     pointTime = System.currentTimeMillis();
//    }
//    break;
//   case MotionEvent.ACTION_MOVE:
//    break;
//   case MotionEvent.ACTION_UP:
//    isPoint = false;
//    pointTime = 0;
//    break;
//  }
 
//  return super.onTouchEvent(event);
  return detector.onTouchEvent(event);
 }
 
 private class MyGestureDetector implements GestureDetector.OnGestureListener, GestureDetector.OnDoubleTapListener {
 
  @Override
  public boolean onDown(MotionEvent e) {
   return false;
  }
 
  @Override
  public void onShowPress(MotionEvent e) {
 
  }
 
  @Override
  public boolean onSingleTapUp(MotionEvent e) {
   return false;
  }
 
  @Override
  public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
   return false;
  }
 
  @Override
  public void onLongPress(MotionEvent e) {
 
  }
 
  @Override
  public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
   return false;
  }
 
  @Override
  public boolean onSingleTapConfirmed(MotionEvent e) {
   return false;
  }
 
  @Override
  public boolean onDoubleTap(MotionEvent e) {
   return false;
  }
 
  @Override
  public boolean onDoubleTapEvent(MotionEvent e) {
   return false;
  }
 }
}

package com.ilz.rocketapplication.handaccount.bean;
 
import android.graphics.Color;
 
import com.ilz.rocketapplication.handaccount.utils.ColorUtils;
 
public class SnowBean {
 float x;
 float y;
 float size;
 int color = Color.WHITE;
 
 public float getX() {
  return x;
 }
 
 public void setX(float x) {
  this.x = x;
 }
 
 public float getY() {
  return y;
 }
 
 public void setY(float y) {
  this.y = y;
 }
 
 public float getSize() {
  return size;
 }
 
 public void setSize(float size) {
  this.size = size;
 }
 
 public int getColor() {
  return color;
 }
 
 public void setColor(int color) {
  this.color = color;
 }
}

/**
  * 获取屏幕的宽度
*/
 public static int getWindowsWidth() {
  WindowManager wm = (WindowManager) (MyApplication.getInstance().getSystemService(Context.WINDOW_SERVICE));
  DisplayMetrics dm = new DisplayMetrics();
  wm.getDefaultDisplay().getMetrics(dm);
  int mScreenWidth = dm.widthPixels;
  return mScreenWidth;
 }
 
 /**
  * 获取屏幕的高度
  */
 public static int getWindowsHeight() {
  WindowManager wm = (WindowManager) (MyApplication.getInstance().getSystemService(Context.WINDOW_SERVICE));
  DisplayMetrics dm = new DisplayMetrics();
  wm.getDefaultDisplay().getMetrics(dm);
  int mScreenHeigh = dm.heightPixels;
  return mScreenHeigh;
 }