Android实现波浪球效果

波浪球的效果一直都是想模仿的对象，在最近一段时间里模仿了这一界面，其实所用知识并不多。

1）、波浪的效果是利用三角函数来实现的，在自定义view中创建容量为width的数组，由y=Asin(Kx+T)+H得到每个x相对应的y值，然后存入数组里面。

2）、利用Android中Canvas提供的drawLine来从上部向下画线，每个像素上画完线之后就组成了图像。

3）、自定义view中的变量都与width建立了比例关系，可以任意大小，且效果一致。

4）、分别对y=Asin(Kx+T)+H中的T与H做valueAnimation的数字动画，就能实现波浪和上升的效果。

5）、利用Android中Paint的setXfermode来实现圆形效果。

6）、给外部提供了外部接口，可以对内部状态进行改变。

具体代码如下：

1 界面XML代码：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:id="@+id/activity_wave_view"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:paddingBottom="@dimen/activity_vertical_margin"
  android:paddingLeft="@dimen/activity_horizontal_margin"
  android:paddingRight="@dimen/activity_horizontal_margin"
  android:paddingTop="@dimen/activity_vertical_margin"
  tools:context="com.example.app_switchbutton.WaveViewActivity">

  <Button
    android:id="@+id/begainButtton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="开始"
    android:layout_below="@+id/waveview"
    android:layout_alignParentStart="true" />

  <com.example.app_switchbutton.waveView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/waveview"
    android:layout_alignParentTop="true"
    android:layout_alignParentStart="true"
    android:layout_marginStart="11dp" />

</RelativeLayout>

2、waveView的java代码：

package com.example.app_switchbutton;

import android.animation.ValueAnimator;
import android.content.Context;
import android.content.pm.ProviderInfo;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

/**
 * Created by 尽途 on 2017/4/30.
 */

public class waveView extends View {
  private int widthSize;
  private int heightSize;
  private float[] mContentOneYs=null;
  private float[] mContentTwoYs=null;
  private float[] restoreOnes=null;
  private float[] restoreTwos=null;
  private float n=0.5f;
  private int SWINGONE;
  private int SWINGTWO;
  private int OFFSETONE=0;
  private int OFFSETTWO=0;
  private Paint mPaint1;
  private Paint mPaint2;
  private Paint circlePaint;
  private Canvas bitmapCanvas;
  private Bitmap bitmap;
  private float endValue;

  public waveView(Context context){
    super(context);
    init();
  }
  public waveView(Context context, AttributeSet attributeSet){
    super(context,attributeSet);
    init();
  }
  private void init(){
    mPaint1=new Paint();
    mPaint1.setColor(Color.parseColor("#AB9DCF"));
    mPaint1.setStrokeWidth(4);
    mPaint1.setAlpha(240);
    mPaint1.setStyle(Paint.Style.FILL);
    mPaint1.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));

    mPaint2=new Paint();
    mPaint2.setColor(Color.parseColor("#A2D1F3"));
    mPaint2.setStrokeWidth(4);
    mPaint2.setAlpha(240);
    mPaint2.setStyle(Paint.Style.FILL);
    mPaint2.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));

    circlePaint=new Paint();
    circlePaint.setAntiAlias(true);
    circlePaint.setColor(Color.GRAY);
    // circlePaint.setAlpha(56);

  }

  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    widthSize=MeasureSpec.getSize(widthMeasureSpec);
    heightSize=widthSize;
    setMeasuredDimension(widthSize,heightSize);

    bitmap=Bitmap.createBitmap(widthSize,heightSize, Bitmap.Config.ARGB_8888);//实现圆球效果
    bitmapCanvas=new Canvas(bitmap);
    SWINGONE=widthSize/20;
    SWINGTWO=widthSize/10;
  }

  @Override
  protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    super.onSizeChanged(w, h, oldw, oldh);
    getPoints();
  }
  private void getPoints(){
    mContentOneYs=new float[widthSize];
    mContentTwoYs=new float[widthSize];
    restoreOnes=new float[widthSize];
    restoreTwos=new float[widthSize];
    for (int i=0;i<widthSize;i++){
      mContentOneYs[i]=getposition1(i,SWINGONE,OFFSETONE,(int)(widthSize*n));
      mContentTwoYs[i]=getposition2(i,SWINGTWO,OFFSETTWO,(int)(widthSize*n));
    }
  }
  private float getposition1(int x,int swing,int offset,int baseHeight){
    float cycle=(float)(2*Math.PI)/widthSize;
    return (float)Math.sin(cycle*x+offset)*swing+baseHeight;
  }
  private float getposition2(int x,int swing,int offset,int baseHeight){
    float cycle=(float)(2*Math.PI)/widthSize;
    return (float)Math.cos(cycle*x+offset)*swing+baseHeight;
  }

  @Override
  protected void onDraw(Canvas canvas) {
    bitmapCanvas.drawCircle(widthSize/2,heightSize/2,widthSize/2,circlePaint);//实现圆球效果

    canvas.save();
    getPoints();
    for (int i=0;i<widthSize;i++){
      final float x=i;
      final float y1=mContentOneYs[i];
      final float y2=mContentTwoYs[i];
      bitmapCanvas.drawLine(x,y1,x,heightSize,mPaint2);//实现了线的绘制最终生成了图，在画的球上画的线
      bitmapCanvas.drawLine(x,y2,x,heightSize,mPaint1);
    }
    canvas.drawBitmap(bitmap,0,0,null);//将球画在了主界面的View中。
  }

  @Override
  public boolean onTouchEvent(MotionEvent event) {//按下就会产生动画效果
    switch (event.getAction()){
      case MotionEvent.ACTION_DOWN:
        return true;
      case MotionEvent.ACTION_MOVE:
        return false;
      case MotionEvent.ACTION_UP:
        begainAnimation();
        invalidate();
        default:
          break;
    }
    return super.onTouchEvent(event);
  }

  public void begainAnimation(){//所有动画的实现都在这个函数里面
    final ValueAnimator valueAnimator=ValueAnimator.ofInt(0,20);
    final ValueAnimator valueAnimator1=ValueAnimator.ofInt(0,20);
    final ValueAnimator valueAnimator2=ValueAnimator.ofFloat(1,0.5f);
    valueAnimator2.setDuration(5000);
    valueAnimator.setDuration(5000);
    valueAnimator1.setDuration(5000);
    valueAnimator.setTarget(OFFSETTWO);
    valueAnimator1.setTarget(OFFSETONE);
    valueAnimator2.setTarget(n);
    valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
      @Override
      public void onAnimationUpdate(ValueAnimator animation) {
        OFFSETTWO=(int)valueAnimator.getAnimatedValue();
        invalidate();
      }
    });
    valueAnimator1.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
      @Override
      public void onAnimationUpdate(ValueAnimator animation) {
        OFFSETONE=(int)valueAnimator1.getAnimatedValue();
        invalidate();
      }
    });
    valueAnimator2.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
      @Override
      public void onAnimationUpdate(ValueAnimator animation) {
        n=(float)valueAnimator2.getAnimatedValue();
      }
    });
    valueAnimator.start();
    valueAnimator1.start();
    valueAnimator2.start();
  }
  public void changgeState(float endValue){//给外部的一个接口
    this.endValue=1-endValue;
    begainAnimation();
  }

}

3、waveActivity的java代码：

package com.example.app_switchbutton;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class WaveViewActivity extends AppCompatActivity {
  private Button begainButton;
  private waveView waveview;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_wave_view);
    waveview=(waveView)findViewById(R.id.waveview);
    begainButton=(Button)findViewById(R.id.begainButtton);
    begainButton.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        waveview.begainAnimation();
      }
    });
  }
}

在此也多些网上的老前辈的学习代码。

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