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<com.airsaid.diffuseview.widget.DiffuseViewandroid:id="@+id/diffuseView"android:layout_width="match_parent"android:layout_height="0dp"android:layout_weight="1"app:diffuse_color="@color/colorAccent"app:diffuse_coreColor="@color/colorPrimaryDark"app:diffuse_coreImage="@android:drawable/ic_menu_search"app:diffuse_coreRadius="100"app:diffuse_maxWidth="300"app:diffuse_width="4"/>

DiffuseView mDiffuseView = (DiffuseView) findViewById(R.id.diffuseView);
mDiffuseView.start(); // 开始扩散
mDiffuseView.stop();// 停止扩散

/*** Created by zhouyou on 2016/9/27.* Class desc:** 这是一个自定义圆圈扩散View*/
public class DiffuseView extends View {/** 扩散圆圈颜色 */private int mColor = getResources().getColor(R.color.colorAccent);/** 圆圈中心颜色 */private int mCoreColor = getResources().getColor(R.color.colorPrimary);/** 圆圈中心图片 */private Bitmap mBitmap;/** 中心圆半径 */private float mCoreRadius = 150;/** 扩散圆宽度 */private int mDiffuseWidth = 3;/** 最大宽度 */private Integer mMaxWidth = 255;/** 是否正在扩散中 */private boolean mIsDiffuse = false;// 透明度集合private List<Integer> mAlphas = new ArrayList<>();// 扩散圆半径集合private List<Integer> mWidths = new ArrayList<>();private Paint mPaint;public DiffuseView(Context context) {this(context, null);}public DiffuseView(Context context, AttributeSet attrs) {this(context, attrs, -1);}public DiffuseView(Context context, AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);init();TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.DiffuseView, defStyleAttr, 0);mColor = a.getColor(R.styleable.DiffuseView_diffuse_color, mColor);mCoreColor = a.getColor(R.styleable.DiffuseView_diffuse_coreColor, mCoreColor);mCoreRadius = a.getFloat(R.styleable.DiffuseView_diffuse_coreRadius, mCoreRadius);mDiffuseWidth = a.getInt(R.styleable.DiffuseView_diffuse_width, mDiffuseWidth);mMaxWidth = a.getInt(R.styleable.DiffuseView_diffuse_maxWidth, mMaxWidth);int imageId = a.getResourceId(R.styleable.DiffuseView_diffuse_coreImage, -1);if(imageId != -1) mBitmap = BitmapFactory.decodeResource(getResources(), imageId);a.recycle();}private void init() {mPaint = new Paint();mPaint.setAntiAlias(true);mAlphas.add(255);mWidths.add(0);}@Overridepublic void invalidate() {if(hasWindowFocus()){super.invalidate();}}@Overridepublic void onDraw(Canvas canvas) {// 绘制扩散圆
        mPaint.setColor(mColor);for (int i = 0; i < mAlphas.size(); i++) {// 设置透明度Integer alpha = mAlphas.get(i);mPaint.setAlpha(alpha);// 绘制扩散圆Integer width = mWidths.get(i);canvas.drawCircle(getWidth() / 2, getHeight() / 2, mCoreRadius + width, mPaint);if(alpha > 0 && width < mMaxWidth){mAlphas.set(i, alpha - 1);mWidths.set(i, width + 1);}}// 判断当扩散圆扩散到指定宽度时添加新扩散圆if (mWidths.get(mWidths.size() - 1) == mMaxWidth / mDiffuseWidth) {mAlphas.add(255);mWidths.add(0);}// 超过10个扩散圆，删除最外层if(mWidths.size() >= 10){mWidths.remove(0);mAlphas.remove(0);}// 绘制中心圆及图片mPaint.setAlpha(255);mPaint.setColor(mCoreColor);canvas.drawCircle(getWidth() / 2, getHeight() / 2, mCoreRadius, mPaint);if(mBitmap != null){canvas.drawBitmap(mBitmap, getWidth() / 2 - mBitmap.getWidth() / 2, getHeight() / 2 - mBitmap.getHeight() / 2, mPaint);}if(mIsDiffuse){invalidate();}}/*** 开始扩散*/public void start() {mIsDiffuse = true;invalidate();}/*** 停止扩散*/public void stop() {mIsDiffuse = false;}/*** 是否扩散中*/public boolean isDiffuse(){return mIsDiffuse;}/*** 设置扩散圆颜色*/public void setColor(int colorId){mColor = colorId;}/*** 设置中心圆颜色*/public void setCoreColor(int colorId){mCoreColor = colorId;}/*** 设置中心圆图片*/public void setCoreImage(int imageId){mBitmap = BitmapFactory.decodeResource(getResources(), imageId);}/*** 设置中心圆半径*/public void setCoreRadius(int radius){mCoreRadius = radius;}/*** 设置扩散圆宽度(值越小宽度越大)*/public void setDiffuseWidth(int width){mDiffuseWidth = width;}/*** 设置最大宽度*/public void setMaxWidth(int maxWidth){mMaxWidth = maxWidth;}
}