本文实例为大家分享了Android 5.0 实现水波扩散效果的具体代码，供大家参考，具体内容如下
该效果是通过自定义界面来实现的
1、首先自定义属性，attrs.xml代码如下：
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<?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> |
其中属性rippleColor为水波动画的颜色，rippleAlpha为其透明度，rippleTime为动画持续时间，maskAlpha为触摸遮掩层的透明度。
2、自定义RippleView类继承RelativeLayout布局，也可以由需求所定继承于其它类，实现水波扩散效果主要的有两点：水波扩散的绘制和动画
1)水波的绘制其实就是绘制一个圆形
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canvas.drawCircle(mDownX, mDownY, mRadius, mRipplePaint); |
2)动画效果就是该圆形的绘制从小到大的过程，而该圆形到最大时的半径长度就是当前所在布局的对角线长度：
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@Overrideprotected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); // 获取最大半径 mMaxRadius = (float) Math.sqrt(w * w + h * h);} |
动画效果用属性动画ObjectAnimator来实现（ObjectAnimator是android3.0后出现的）如下
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mRippleAnim = ObjectAnimator.ofFloat(this, "radius", 0, mMaxRadius);mRippleAnim.setInterpolator(new AccelerateDecelerateInterpolator());mRippleAnim.setDuration(mRippleTime); |
其中的radius为自定义的属性，在动画执行时会回调对应的方法，只需要在该方法中更新圆形的半径就行了
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public void setRadius(final float radius) { mRadius = radius; invalidate();} |
RippleView完整代码如下：
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public class RippleView extends RelativeLayout { private int mRippleColor;// 水波颜色 private float mMaskAlpha;// 遮掩透明度 private float mRippleAlpha;// 水波透明度 private int mRippleTime;// 水波动画时间 private ObjectAnimator mRippleAnim;// 显示水波动画 private float mRadius;// 当前的半径 private float mMaxRadius;// 水波最大半径 private float mDownX; // 记录手指按下的位置 private float mDownY; private boolean mIsMask; private boolean mIsAnimating;// 是否正在播放动画 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(); // 获取自定义属性 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)); } // 初始化动画 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); // 获取最大半径 mMaxRadius = (float) Math.sqrt(w * w + h * h); // 获取该类布局范围 mRect = new RectF(0f, 0f, getMeasuredWidth() * 1.0f, getMeasuredHeight() * 1.0f); // 初始化动画 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); // 绘制遮掩 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(); } // 绘制水波 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(); } // 属性动画回调的方法 public void setRadius(final float radius) { mRadius = radius; invalidate(); }} |
界面布局代码
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<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内容，希望对大家的学习有所帮助，也希望大家多多支持服务器之家。
原文链接：https://blog.csdn.net/a874508605/article/details/50859066
