Android营造雪花和雨滴浪漫效果

本文在实现雪花效果的基础上，根据漫天飞舞雪花，实现下雨天场景的效果，使用eclipse android 版本，具体内容如下

雪花效果图：

具体代码：

1、漫天飞舞的雪花主要代码
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; 
 
/** 
 * 雪花视图, delay时间重绘, 绘制num_snowflakes个雪花 
 */ 
public class snowview extends view { 
 
 private static final int num_snowflakes = 150; // 雪花数量 
 private static final int delay = 5; // 延迟 
 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); // 抗锯齿 
 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这里面 
 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) { 
  //然后进行绘制 
  s.draw(canvas); 
 } 
 // 隔一段时间重绘一次, 动画效果 
 gethandler().postdelayed(runnable, delay); 
 } 
 
 // 重绘线程 
 private runnable runnable = new runnable() { 
 @override 
 public void run() { 
  //自动刷新 
  invalidate(); 
 } 
 }; 
} 

snowflake

package com.example.snowflake.view; 
 
import com.example.snowflake.randomgenerator; 
 
import android.graphics.canvas; 
import android.graphics.paint; 
import android.graphics.point; 
 
/** 
 * 雪花的类, 移动, 移出屏幕会重新设置位置. 
 */ 
public class snowflake { 
 // 雪花的角度 
 private static final float ange_range = 0.1f; // 角度范围 
 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; // 角度随机种子 
 private static final float angle_divisor = 10000f; 
 // 雪花的移动速度 
 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; // 随机控制器 
 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; // 画笔 
 
 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); 
 } 
 
 // 绘制雪花 
 public void draw(canvas canvas) { 
 int width = canvas.getwidth(); 
 int height = canvas.getheight(); 
 move(width, height); 
 canvas.drawcircle(mposition.x, mposition.y, mflakesize, mpaint); 
 } 
 
 // 移动雪花 
 private void move(int width, int height) { 
 //x水平方向，那么需要晃动，主要设置这个值就可以，现在取消晃动了 
 //如果 mposition.x不加上后面那个值，就不会晃动了 
 double x = mposition.x + (mincrement * math.cos(mangle)); 
 //y是竖直方向，就是下落 
 double y = mposition.y + (mincrement * math.sin(mangle)); 
 
 mangle += mrandom.getrandom(-angle_seed, angle_seed) / angle_divisor; 
 //这个是设置雪花位置，如果在很短时间内刷新一次，就是连起来的动画效果 
 mposition.set((int) x, (int) y); 
 
 // 移除屏幕, 重新开始 
 if (!isinside(width, height)) { 
  // 重置雪花 
  reset(width); 
 } 
 } 
 
 // 判断是否在其中 
 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; 
 } 
} 

2、实现下雨天效果代码
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; 
 
/** 
 * 雨滴视图, delay时间重绘, 绘制num_snowflakes个雨滴 
 */ 
public class rainview extends view { 
 
 private static final int num_snowflakes = 150; // 雨滴数量 
 private static final int delay = 5; // 延迟 
 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); // 抗锯齿 
 paint.setcolor(getresources().getcolor(r.color.colorwater)); // 雨滴的颜色 
 paint.setstyle(paint.style.fill); // 填充; 
 msnowflakes = new rainflake[num_snowflakes]; 
 //msnowflakes所有的雨滴都生成放到这里面 
 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) { 
  //然后进行绘制 
  s.draw(canvas); 
 } 
 // 隔一段时间重绘一次, 动画效果 
 gethandler().postdelayed(runnable, delay); 
 } 
 
 // 重绘线程 
 private runnable runnable = new runnable() { 
 @override 
 public void run() { 
  //自动刷新 
  invalidate(); 
 } 
 }; 
} 

rainflake

package com.example.raindrop.view; 
 
import com.example.raindrop.randomgenerator; 
 
import android.graphics.canvas; 
import android.graphics.paint; 
 
/** 
 * 雨滴的类, 移动, 移出屏幕会重新设置位置. 
 */ 
public class rainflake { 
 
 // 雨滴的移动速度 
 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; // 画笔 
 
 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); 
 } 
 
 // 绘制雨滴 
 public void draw(canvas canvas) { 
 int width = canvas.getwidth(); 
 int height = canvas.getheight(); 
 drawline(canvas, width, height); 
 } 
 
 /** 
 * 改成线条，类似于雨滴效果 
 * @param canvas 
 * @param width 
 * @param height 
 */ 
 private void drawline(canvas canvas, int width, int height) { 
 //设置线宽 
 mpaint.setstrokewidth(mflakesize); 
 //y是竖直方向，就是下落 
 double y1 = mline.y1 + (mincrement * math.sin(1.5)); 
 double y2 = mline.y2 + (mincrement * math.sin(1.5)); 
 
 //这个是设置雨滴位置，如果在很短时间内刷新一次，就是连起来的动画效果 
 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); 
 } 
 
 // 判断是否在其中 
 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]; 
 } 
 
} 

雨滴效果图：

以上就是本文的全部内容，帮助大家轻松实现浪漫的雪花雨滴效果，大家可以把效果运用到自己的项目中，希望大家喜欢。