android 實現漫天飛舞雪花以及下雨天的效果

BigWang 8年前發布 | 15K 次閱讀 Android開發移動開發

來自： http://blog.csdn.net/qq_16064871/article/details/50603105

前言：

這個效果實現的原作者是國外一位大神。我在其基礎上測試，以及在代碼上加了不少注釋，以及局部修改。后面我有根據漫天飛舞雪花，實現下雨天場景的效果。原作者項目還是android studio版本的。我改成eclipse android 版本。

英文原文地址：https://blog.stylingandroid.com/snowfall/

中文翻譯地址：http://www.baiduhome.net/lib/view/open1452263908573.html

國外大神實現效果油Tube視頻地址：https://www.油Tube.com/watch?v=pk66ZziTfOw

中文翻譯是open開發者經驗庫一位作者翻譯，翻譯的很好。在那篇文章也能看到實現的最原始的效果。

實現漫天飛舞的雪花下載地址：http://download.csdn.net/detail/qq_16064871/9420804

實現下雨天效果的下載地址：http://download.csdn.net/detail/qq_16064871/9420808

1、漫天飛舞的雪花主要代碼

SnowView

<span style="font-size:14px;">package com.ex</span>ample.snowflake.view;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;
/**

雪花視圖, DELAY時間重繪, 繪制NUM_SNOWFLAKES個雪花
*/
public class SnowView extends View {
private static final int NUM_SNOWFLAKES = 150; // 雪花數量
 private static final int DELAY = 5; // 延遲
 private SnowFlake[] mSnowFlakes; // 雪花
public SnowView(Context context) {

 super(context);

}
public SnowView(Context context, AttributeSet attrs) {

 super(context, attrs);

}
public SnowView(Context context, AttributeSet attrs, int defStyleAttr) {

 super(context, attrs, defStyleAttr);

}
@Override 
 protected void onSizeChanged(int w, int h, int oldw, int oldh) {

 super.onSizeChanged(w, h, oldw, oldh);
 if (w != oldw || h != oldh) {
     initSnow(w, h);
 }

}
private void initSnow(int width, int height) {

 Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG); // 抗鋸齒
 paint.setColor(Color.WHITE); // 白色雪花
 paint.setStyle(Paint.Style.FILL); // 填充;
 mSnowFlakes = new SnowFlake[NUM_SNOWFLAKES];
 //mSnowFlakes所有的雪花都生成放到這里面
 for (int i = 0; i < NUM_SNOWFLAKES; ++i) {
     mSnowFlakes[i] = SnowFlake.create(width, height, paint);
 }

}
@Override 
 protected void onDraw(Canvas canvas) {

 super.onDraw(canvas);
 //for返回SnowFlake
 for (SnowFlake s : mSnowFlakes) {
     //然后進行繪制
     s.draw(canvas);
 }
 // 隔一段時間重繪一次, 動畫效果
 getHandler().postDelayed(runnable, DELAY);

}
// 重繪線程
 private Runnable runnable = new Runnable() {

 @Override
 public void run() {
     //自動刷新
     invalidate();
 }

};
}</pre> SnowFlake 


package com.example.snowflake.view;


import com.example.snowflake.RandomGenerator;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Point;
/**

雪花的類, 移動, 移出屏幕會重新設置位置.
*/
public class SnowFlake {
 // 雪花的角度
 private static final float ANGE_RANGE = 0.1f; // 角度范圍
 private static final float HALF_ANGLE_RANGE = ANGE_RANGE / 2f; // 一般的角度
 private static final float HALF_PI = (float) Math.PI / 2f; // 半PI
 private static final float ANGLE_SEED = 25f; // 角度隨機種子
 private static final float ANGLE_DIVISOR = 10000f;
 // 雪花的移動速度
 private static final float INCREMENT_LOWER = 2f;
 private static final float INCREMENT_UPPER = 4f;
// 雪花的大小
 private static final float FLAKE_SIZE_LOWER = 7f;
 private static final float FLAKE_SIZE_UPPER = 20f;
private final RandomGenerator mRandom; // 隨機控制器
 private final Point mPosition; // 雪花位置
 private float mAngle; // 角度
 private final float mIncrement; // 雪花的速度
 private final float mFlakeSize; // 雪花的大小
 private final Paint mPaint; // 畫筆
private SnowFlake(RandomGenerator random, Point position, float angle, float increment, float flakeSize, Paint paint) {

 mRandom = random;
 mPosition = position;
 mIncrement = increment;
 mFlakeSize = flakeSize;
 mPaint = paint;
 mAngle = angle;

}
public static SnowFlake create(int width, int height, Paint paint) {

 RandomGenerator random = new RandomGenerator();
 int x = random.getRandom(width);
 int y = random.getRandom(height);
 Point position = new Point(x, y);
 float angle = random.getRandom(ANGLE_SEED) / ANGLE_SEED * ANGE_RANGE + HALF_PI - HALF_ANGLE_RANGE;
 float increment = random.getRandom(INCREMENT_LOWER, INCREMENT_UPPER);
 float flakeSize = random.getRandom(FLAKE_SIZE_LOWER, FLAKE_SIZE_UPPER);
 return new SnowFlake(random, position, angle, increment, flakeSize, paint);

}
// 繪制雪花
 public void draw(Canvas canvas) {

 int width = canvas.getWidth();
 int height = canvas.getHeight();
 move(width, height);
 canvas.drawCircle(mPosition.x, mPosition.y, mFlakeSize, mPaint);

}
// 移動雪花
 private void move(int width, int height) {

 //x水平方向，那么需要晃動，主要設置這個值就可以，現在取消晃動了
 //如果 mPosition.x不加上后面那個值，就不會晃動了
 double x = mPosition.x + (mIncrement * Math.cos(mAngle));
 //y是豎直方向，就是下落
 double y = mPosition.y + (mIncrement * Math.sin(mAngle));

 mAngle += mRandom.getRandom(-ANGLE_SEED, ANGLE_SEED) / ANGLE_DIVISOR;
 //這個是設置雪花位置，如果在很短時間內刷新一次，就是連起來的動畫效果
 mPosition.set((int) x, (int) y);

 // 移除屏幕, 重新開始
 if (!isInside(width, height)) {
     // 重置雪花
     reset(width);
 }

}
// 判斷是否在其中
 private boolean isInside(int width, int height) {

 int x = mPosition.x;
 int y = mPosition.y;
 return x > mFlakeSize -5 && x + mFlakeSize <= width && y >= -mFlakeSize - 1 && y - mFlakeSize < height;

}
// 重置雪花
 private void reset(int width) {

 mPosition.x = mRandom.getRandom(width);
 mPosition.y = (int) (-mFlakeSize - 1); // 最上面
 mAngle = mRandom.getRandom(ANGLE_SEED) / ANGLE_SEED * ANGE_RANGE + HALF_PI - HALF_ANGLE_RANGE;

}
}</pre> 


2、實現下雨天效果代碼

RainView



package com.example.raindrop.view;


import com.example.raindrop.R;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;
/**

雨滴視圖, DELAY時間重繪, 繪制NUM_SNOWFLAKES個雨滴
*/
public class RainView extends View {
private static final int NUM_SNOWFLAKES = 150; // 雨滴數量
 private static final int DELAY = 5; // 延遲
 private RainFlake[] mSnowFlakes; // 雨滴
public RainView(Context context) {

 super(context);

}
public RainView(Context context, AttributeSet attrs) {

 super(context, attrs);

}
public RainView(Context context, AttributeSet attrs, int defStyleAttr) {

 super(context, attrs, defStyleAttr);

}
@Override 
 protected void onSizeChanged(int w, int h, int oldw, int oldh) {

 super.onSizeChanged(w, h, oldw, oldh);
 if (w != oldw || h != oldh) {
     initSnow(w, h);
 }

}
private void initSnow(int width, int height) {

 Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG); // 抗鋸齒
 paint.setColor(getResources().getColor(R.color.colorWater)); // 雨滴的顏色
 paint.setStyle(Paint.Style.FILL); // 填充;
 mSnowFlakes = new RainFlake[NUM_SNOWFLAKES];
 //mSnowFlakes所有的雨滴都生成放到這里面
 for (int i = 0; i < NUM_SNOWFLAKES; ++i) {
     mSnowFlakes[i] = RainFlake.create(width, height, paint);
 }

}
@Override 
 protected void onDraw(Canvas canvas) {

 super.onDraw(canvas);
 //for返回SnowFlake
 for (RainFlake s : mSnowFlakes) {
     //然后進行繪制
     s.draw(canvas);
 }
 // 隔一段時間重繪一次, 動畫效果
 getHandler().postDelayed(runnable, DELAY);

}
// 重繪線程
 private Runnable runnable = new Runnable() {

 @Override
 public void run() {
     //自動刷新
     invalidate();
 }

};
}</pre> 


RainFlake

package com.example.raindrop.view;


import com.example.raindrop.RandomGenerator;
import android.graphics.Canvas;
import android.graphics.Paint;
/**

雨滴的類, 移動, 移出屏幕會重新設置位置.
*/
public class RainFlake {
// 雨滴的移動速度
 private static final float INCREMENT_LOWER = 6f;
 private static final float INCREMENT_UPPER = 8f;
// 雨滴的大小
 private static final float FLAKE_SIZE_LOWER = 2f;
 private static final float FLAKE_SIZE_UPPER = 5f;
private final float mIncrement; // 雨滴的速度
 private final float mFlakeSize; // 雨滴的大小
 private final Paint mPaint; // 畫筆
private Line mLine; // 雨滴
private RandomGenerator mRandom;
private RainFlake(RandomGenerator random,Line line, float increment, float flakeSize, Paint paint) {

 mRandom = random;
 mLine = line;
 mIncrement = increment;
 mFlakeSize = flakeSize;
 mPaint = paint;

}
//生成雨滴
 public static RainFlake create(int width, int height, Paint paint) {

 RandomGenerator random = new RandomGenerator();
 int [] nline;
 nline = random.getLine(width, height);

 Line line = new Line(nline[0], nline[1], nline[2], nline[3]);
 float increment = random.getRandom(INCREMENT_LOWER, INCREMENT_UPPER);
 float flakeSize = random.getRandom(FLAKE_SIZE_LOWER, FLAKE_SIZE_UPPER);
 return new RainFlake(random,line, increment, flakeSize, paint);

}
// 繪制雨滴
 public void draw(Canvas canvas) {

 int width = canvas.getWidth();
 int height = canvas.getHeight();
 drawLine(canvas, width, height);

}
/**

改成線條，類似于雨滴效果
@param canvas
@param width
@param height
/
private void drawLine(Canvas canvas, int width, int height) {
 //設置線寬
mPaint.setStrokeWidth(mFlakeSize);
 //y是豎直方向，就是下落
double y1 = mLine.y1 + (mIncrement  Math.sin(1.5));
double y2 = mLine.y2 + (mIncrement * Math.sin(1.5));
//這個是設置雨滴位置，如果在很短時間內刷新一次，就是連起來的動畫效果
mLine.set(mLine.x1,(int) y1,mLine.x2 ,(int) y2);
if (!isInsideLine(height)) {

 resetLine(width,height);

}
canvas.drawLine(mLine.x1, mLine.y1, mLine.x2, mLine.y2, mPaint);
}
// 判斷是否在其中
private boolean isInsideLine(int height) {
 return mLine.y1 < height && mLine.y2 < height;
}
// 重置雨滴
private void resetLine(int width, int height) {
 int [] nline;
 nline = mRandom.getLine(width, height);
 mLine.x1 = nline[0];
 mLine.y1 = nline[1];
 mLine.x2 = nline[2];
 mLine.y2 = nline[3];
}




}</pre> 

 

 3、效果圖
 
 

 
 

 
 

 
 在這里我說一下為什么是沒有gif效果圖，android手機錄制屏幕太太麻煩了，還要轉為gif。以前我是用騰訊應用寶截圖做成gif效果圖。但是這次效果不好我就直接截圖了。
 需要看動畫效果，下載我demo。或者去中文翻譯那片文章也有效果圖。
 還有各位有什么推薦工具，關于android 機器錄制gif工具或者軟件。
 再次說明以下：
 
 英文原文地址：https://blog.stylingandroid.com/snowfall/
 中文翻譯地址：http://www.baiduhome.net/lib/view/open1452263908573.html
 國外大神實現效果油Tube視頻地址：https://www.油Tube.com/watch?v=pk66ZziTfOw 

 
 中文翻譯是open開發者經驗庫一位作者翻譯，翻譯的很好。在那篇文章也能看到實現的最原始的效果。
 實現漫天飛舞的雪花下載地址：http://download.csdn.net/detail/qq_16064871/9420804
 實現下雨天效果的下載地址：http://download.csdn.net/detail/qq_16064871/9420808