Android自定义View 实现水波纹动画引导效果

package com.czhappy.showintroduce.view;import android.content.Context;import android.graphics.Bitmap;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.Path;import android.util.AttributeSet;import android.view.View;import android.widget.RelativeLayout;/** * Description: 水波纹动画引导view * User: chenzheng * Date: 2017/1/14 0014 * Time: 18:01 */public class RippleIntroView extends RelativeLayout implements Runnable {  private int mMaxRadius = 70;  private int mInterval = 20;  private int count = 0;  private Bitmap mCacheBitmap;  private Paint mRipplePaint;  private Paint mCirclePaint;  private Path mArcPath;  public RippleIntroView(Context context) {    this(context, null);  }  public RippleIntroView(Context context, AttributeSet attrs) {    this(context, attrs, 0);  }  public RippleIntroView(Context context, AttributeSet attrs, int defStyleAttr) {    super(context, attrs, defStyleAttr);    init();  }  private void init() {    mRipplePaint = new Paint();    mRipplePaint.setAntiAlias(true);    mRipplePaint.setStyle(Paint.Style.STROKE);    mRipplePaint.setColor(Color.WHITE);    mRipplePaint.setStrokeWidth(2.f);    mCirclePaint = new Paint();    mCirclePaint.setAntiAlias(true);    mCirclePaint.setStyle(Paint.Style.FILL);    mCirclePaint.setColor(Color.WHITE);    mArcPath = new Path();  }  /**   * view大小变化时系统调用   * @param w   * @param h   * @param oldw   * @param oldh   */  @Override  protected void onSizeChanged(int w, int h, int oldw, int oldh) {    super.onSizeChanged(w, h, oldw, oldh);    if (mCacheBitmap != null) {      mCacheBitmap.recycle();      mCacheBitmap = null;    }  }  @Override  protected void onDraw(Canvas canvas) {    //获取加号图片view    View mPlusChild = getChildAt(0);    //获取提示图片view    View mRefsChild = getChildAt(1);    if (mPlusChild == null || mRefsChild == null) return;    //获取加号图片大小    final int pw = mPlusChild.getWidth();    final int ph = mPlusChild.getHeight();    //获取提示图片大小    final int fw = mRefsChild.getWidth();    final int fh = mRefsChild.getHeight();    if (pw == 0 || ph == 0) return;    //加号图片中心点坐标    final float px = mPlusChild.getX() + pw / 2;    final float py = mPlusChild.getY() + ph / 2;    //提示图片左上角坐标    final float fx = mRefsChild.getX();    final float fy = mRefsChild.getY();    final int rw = pw / 2;    final int rh = ph / 2;    if (mCacheBitmap == null) {      mCacheBitmap = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888);      Canvas cv = new Canvas(mCacheBitmap);      super.onDraw(cv);      //清空所有已经画过的path至原始状态      mArcPath.reset();      //起始轮廓点移至x，y坐标点,即加号图片正下方再往下20位置      mArcPath.moveTo(px, py + rh + mInterval);      //设置二次贝塞尔，实现平滑曲线，前两个参数为操作点坐标，后两个参数为结束点坐标      mArcPath.quadTo(px, fy - mInterval, fx + fw * 0.618f, fy - mInterval);      //0~255，数值越小越透明      mRipplePaint.setAlpha(255);      cv.drawPath(mArcPath, mRipplePaint);      //绘制半径为6的实心圆点      cv.drawCircle(px, py + rh + mInterval, 6, mCirclePaint);    }    //绘制背景图片    canvas.drawBitmap(mCacheBitmap, 0, 0, mCirclePaint);    //保存画布当前的状态    int save = canvas.save();    for (int step = count; step <= mMaxRadius; step += mInterval) {      //step越大越靠外就越透明      mRipplePaint.setAlpha(255 * (mMaxRadius - step) / mMaxRadius);      canvas.drawCircle(px, py, (float) (rw + step), mRipplePaint);    }    //恢复Canvas的状态    canvas.restoreToCount(save);    //延迟80毫秒后开始运行    postDelayed(this, 80);  }  @Override  public void run() {    //把run对象的引用从队列里拿出来，这样，他就不会执行了，但 run 没有销毁    removeCallbacks(this);    count += 2;    count %= mInterval;    invalidate();//重绘  }  /**   * 销毁view时调用，收尾工作   */  @Override  protected void onDetachedFromWindow() {    super.onDetachedFromWindow();    if (mCacheBitmap != null) {      mCacheBitmap.recycle();      mCacheBitmap = null;    }  }}

package com.czhappy.showintroduce.activity;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.view.ViewGroup;import com.czhappy.showintroduce.R;public class MainActivity extends AppCompatActivity {  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    View view = findViewById(R.id.layout_ripple);    view.setOnClickListener(new View.OnClickListener() {      @Override      public void onClick(View v) {        ((ViewGroup) v.getParent()).removeView(v);      }    });  }}

<?xml version="1.0" encoding="utf-8"?><FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="match_parent">  <TextView    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:text="Hello World!" />  <com.czhappy.showintroduce.view.RippleIntroView    android:id="@+id/layout_ripple"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:clickable="true"    android:fitsSystemWindows="true"    android:background="#AA000000">    <ImageView      android:id="@+id/iv_plus"      android:layout_marginTop="36dp"      android:src="@mipmap/ic_add"      android:layout_alignParentRight="true"      android:layout_marginRight="6dp"      android:layout_width="wrap_content"      android:layout_height="wrap_content"/>    <ImageView      android:src="@mipmap/tips_subscribe"      android:id="@+id/tv_title"      android:layout_below="@id/iv_plus"      android:layout_marginTop="50dp"      android:layout_alignParentRight="true"      android:layout_marginRight="40dp"      android:layout_width="wrap_content"      android:layout_height="wrap_content"/>  </com.czhappy.showintroduce.view.RippleIntroView></FrameLayout>