本文實例為大家分享了Android 5.0 實現水波擴散效果的具體代碼，供大家參考，具體內容如下
該效果是通過自定義界面來實現的
1、首先自定義屬性，attrs.xml代碼如下：
<?xml version="1.0" encoding="utf-8"?><resources> <declare-styleable name="RippleView"> <attr name="rippleColor" format="color" /> <attr name="rippleAlpha" format="float" /> <attr name="maskAlpha" format="float" /> <attr name="rippleTime" format="integer" /> </declare-styleable> </resources>
其中屬性rippleColor為水波動畫的顏色，rippleAlpha為其透明度，rippleTime為動畫持續時間，maskAlpha為觸摸遮掩層的透明度。
2、自定義RippleView類繼承RelativeLayout布局，也可以由需求所定繼承于其它類，實現水波擴散效果主要的有兩點：水波擴散的繪制和動畫
1)水波的繪制其實就是繪制一個圓形
canvas.drawCircle(mDownX, mDownY, mRadius, mRipplePaint);
2)動畫效果就是該圓形的繪制從小到大的過程，而該圓形到最大時的半徑長度就是當前所在布局的對角線長度：
@Overrideprotected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); // 獲取最大半徑 mMaxRadius = (float) Math.sqrt(w * w + h * h);}動畫效果用屬性動畫ObjectAnimator來實現（ObjectAnimator是android3.0后出現的）如下
mRippleAnim = ObjectAnimator.ofFloat(this, "radius", 0, mMaxRadius);mRippleAnim.setInterpolator(new AccelerateDecelerateInterpolator());mRippleAnim.setDuration(mRippleTime);
其中的radius為自定義的屬性，在動畫執行時會回調對應的方法，只需要在該方法中更新圓形的半徑就行了
public void setRadius(final float radius) { mRadius = radius; invalidate();}RippleView完整代碼如下：
public class RippleView extends RelativeLayout { private int mRippleColor;// 水波顏色 private float mMaskAlpha;// 遮掩透明度 private float mRippleAlpha;// 水波透明度 private int mRippleTime;// 水波動畫時間 private ObjectAnimator mRippleAnim;// 顯示水波動畫 private float mRadius;// 當前的半徑 private float mMaxRadius;// 水波最大半徑 private float mDownX; // 記錄手指按下的位置 private float mDownY; private boolean mIsMask; private boolean mIsAnimating;// 是否正在播放動畫 private RectF mRect; private Path mPath; private Paint mMaskPaint; private Paint mRipplePaint; public RippleView(Context context) { this(context, null); } public RippleView(Context context, AttributeSet attrs) { this(context, attrs, 0); } public RippleView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); init(); // 獲取自定義屬性 TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.RippleView); mRippleColor = ta.getColor(R.styleable.RippleView_rippleColor, mRippleColor); mMaskAlpha = ta.getFloat(R.styleable.RippleView_maskAlpha, mMaskAlpha); mRippleAlpha = ta.getFloat(R.styleable.RippleView_rippleAlpha, mRippleAlpha); mRippleTime = ta.getInt(R.styleable.RippleView_rippleTime, mRippleTime); ta.recycle(); initLast(); } // 初始化方法 private void init() { mRippleColor = Color.BLACK; mMaskAlpha = 0.4f; mRippleAlpha = 0.8f; mRippleTime = 800; mPath = new Path(); mMaskPaint = new Paint(Paint.ANTI_ALIAS_FLAG); mRipplePaint = new Paint(Paint.ANTI_ALIAS_FLAG); } // 初始化 private void initLast() { mMaskPaint.setColor(mRippleColor); mRipplePaint.setColor(mRippleColor); mMaskPaint.setAlpha((int) (mMaskAlpha * 255)); mRipplePaint.setAlpha((int) (mRippleAlpha * 255)); } // 初始化動畫 private void initAnim() { mRippleAnim = ObjectAnimator.ofFloat(this, "radius", 0, mMaxRadius); mRippleAnim.setInterpolator(new AccelerateDecelerateInterpolator()); mRippleAnim.setDuration(mRippleTime); mRippleAnim.addListener(new Animator.AnimatorListener() { @Override public void onAnimationStart(Animator animator) { mIsAnimating = true; } @Override public void onAnimationEnd(Animator animator) { setRadius(0); mIsMask = false; mIsAnimating = false; } @Override public void onAnimationCancel(Animator animator) { } @Override public void onAnimationRepeat(Animator animator) { } }); } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); // 獲取最大半徑 mMaxRadius = (float) Math.sqrt(w * w + h * h); // 獲取該類布局范圍 mRect = new RectF(0f, 0f, getMeasuredWidth() * 1.0f, getMeasuredHeight() * 1.0f); // 初始化動畫 initAnim(); } @Override public boolean onTouchEvent(MotionEvent event) { // 按下事件 if (event.getAction() == MotionEvent.ACTION_DOWN) { mIsMask = true; invalidate(); } else if (event.getAction() == MotionEvent.ACTION_MOVE) { invalidate(); } // 抬起事件 else if (event.getAction() == MotionEvent.ACTION_UP) { mDownX = event.getX(); mDownY = event.getY(); if (mIsAnimating) { mRippleAnim.cancel(); } boolean isInView = mRect.contains(mDownX, mDownY); if (isInView) { mRippleAnim.start(); } else { mIsMask = false; invalidate(); } } return true; } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); // 繪制遮掩 if (mIsMask) { canvas.save(Canvas.CLIP_SAVE_FLAG); mPath.reset(); mPath.addRect(mRect, Path.Direction.CW); canvas.clipPath(mPath); canvas.drawRect(mRect, mMaskPaint); canvas.restore(); } // 繪制水波 canvas.save(Canvas.CLIP_SAVE_FLAG); mPath.reset(); mPath.addCircle(mDownX, mDownY, mRadius, Path.Direction.CW); canvas.clipPath(mPath); canvas.drawCircle(mDownX, mDownY, mRadius, mRipplePaint); canvas.restore(); } // 屬性動畫回調的方法 public void setRadius(final float radius) { mRadius = radius; invalidate(); }}界面布局代碼
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" xmlns:ripple="http://schemas.android.com/apk/res/com.example.rippleview" android:layout_width="match_parent" android:layout_height="match_parent" android:background="#000000" > <com.example.rippleview.RippleView android:layout_width="match_parent" android:layout_height="100dp" android:layout_centerInParent="true" android:background="#ffffff" android:clickable="true" ripple:rippleColor="#ababab" > <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerInParent="true" android:text="click me" android:textSize="18sp" /> </com.example.rippleview.RippleView> </RelativeLayout>
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持VEVB武林網。
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