兩種方式實現類似水波擴散效果，先上圖為敬
- 自定義view實現
- 動畫實現
自定義view實現
思路分析：通過canvas畫圓，每次改變圓半徑和透明度，當半徑達到一定程度，再次從中心開始繪圓，達到不同層級的效果，通過不斷繪制達到view擴散效果
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private Paint centerPaint; //中心圓paintprivate int radius = 100; //中心圓半徑private Paint spreadPaint; //擴散圓paintprivate float centerX;//圓心xprivate float centerY;//圓心yprivate int distance = 5; //每次圓遞增間距private int maxRadius = 80; //最大圓半徑private int delayMilliseconds = 33;//擴散延遲間隔，越大擴散越慢private List<Integer> spreadRadius = new ArrayList<>();//擴散圓層級數，元素為擴散的距離private List<Integer> alphas = new ArrayList<>();//對應每層圓的透明度 |
style文件里自定義屬性
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<declare-styleable name="SpreadView"> <!--中心圓顏色--> <attr name="spread_center_color" format="color" /> <!--中心圓半徑--> <attr name="spread_radius" format="integer" /> <!--擴散圓顏色--> <attr name="spread_spread_color" format="color" /> <!--擴散間距--> <attr name="spread_distance" format="integer" /> <!--擴散最大半徑--> <attr name="spread_max_radius" format="integer" /> <!--擴散延遲間隔--> <attr name="spread_delay_milliseconds" format="integer" /></declare-styleable> |
初始化
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public SpreadView(Context context) { this(context, null, 0);}public SpreadView(Context context, @Nullable AttributeSet attrs) { this(context, attrs, 0);}public SpreadView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.SpreadView, defStyleAttr, 0); radius = a.getInt(R.styleable.SpreadView_spread_radius, radius); maxRadius = a.getInt(R.styleable.SpreadView_spread_max_radius, maxRadius); int centerColor = a.getColor(R.styleable.SpreadView_spread_center_color, ContextCompat.getColor(context, R.color.colorAccent)); int spreadColor = a.getColor(R.styleable.SpreadView_spread_spread_color, ContextCompat.getColor(context, R.color.colorAccent)); distance = a.getInt(R.styleable.SpreadView_spread_distance, distance); a.recycle(); centerPaint = new Paint(); centerPaint.setColor(centerColor); centerPaint.setAntiAlias(true); //最開始不透明且擴散距離為0 alphas.add(255); spreadRadius.add(0); spreadPaint = new Paint(); spreadPaint.setAntiAlias(true); spreadPaint.setAlpha(255); spreadPaint.setColor(spreadColor);} |
確定圓心位置
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@Overrideprotected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); //圓心位置 centerX = w / 2; centerY = h / 2;} |
自定義view的繪制
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@Overrideprotected void onDraw(Canvas canvas) { super.onDraw(canvas); for (int i = 0; i < spreadRadius.size(); i++) { int alpha = alphas.get(i); spreadPaint.setAlpha(alpha); int width = spreadRadius.get(i); //繪制擴散的圓 canvas.drawCircle(centerX, centerY, radius + width, spreadPaint); //每次擴散圓半徑遞增，圓透明度遞減 if (alpha > 0 && width < 300) { alpha = alpha - distance > 0 ? alpha - distance : 1; alphas.set(i, alpha); spreadRadius.set(i, width + distance); } } //當最外層擴散圓半徑達到最大半徑時添加新擴散圓 if (spreadRadius.get(spreadRadius.size() - 1) > maxRadius) { spreadRadius.add(0); alphas.add(255); } //超過8個擴散圓，刪除最先繪制的圓，即最外層的圓 if (spreadRadius.size() >= 8) { alphas.remove(0); spreadRadius.remove(0); } //中間的圓 canvas.drawCircle(centerX, centerY, radius, centerPaint); //TODO 可以在中間圓繪制文字或者圖片 //延遲更新，達到擴散視覺差效果 postInvalidateDelayed(delayMilliseconds);} |
xml樣式
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<com.airsaid.diffuseview.widget.SpreadView android:id="@+id/spreadView" android:layout_width="match_parent" android:layout_height="wrap_content" app:spread_center_color="@color/colorAccent" app:spread_delay_milliseconds="35" app:spread_distance="5" app:spread_max_radius="90" app:spread_radius="100" app:spread_spread_color="@color/colorAccent" /> |
效果圖
中心圓處可以自定義寫文字，畫圖片等等...
動畫實現
思路分析：通過動畫實現，imageView不停做動畫縮放+漸變
最中心的imageView保持不變
中間一層imageView從原始放大到1.4倍，同時從不透明變為半透明
最外層的imageView從1.4倍放大到1.8倍，同時從半透明變為全透明
利用shape畫一個圓，作為動畫基礎視圖
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<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android"> <corners android:radius="65dp"/> <solid android:color="@color/colorAccent"/></shape> |
布局視圖
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<FrameLayout android:layout_width="match_parent" android:layout_height="match_parent"> <!--中心imageView--> <ImageView android:id="@+id/iv_wave" android:layout_width="130dp" android:layout_height="130dp" android:layout_gravity="center" android:background="@drawable/shape_circle" /> <!--中間的imageView--> <ImageView android:id="@+id/iv_wave_1" android:layout_width="130dp" android:layout_height="130dp" android:layout_gravity="center" android:background="@drawable/shape_circle" /> <!--最外層imageView--> <ImageView android:id="@+id/iv_wave_2" android:layout_width="130dp" android:layout_height="130dp" android:layout_gravity="center" android:background="@drawable/shape_circle" /></FrameLayout> |
中間imageView的動畫
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private void setAnim1() { AnimationSet as = new AnimationSet(true); //縮放動畫，以中心從原始放大到1.4倍 ScaleAnimation scaleAnimation = new ScaleAnimation(1.0f, 1.4f, 1.0f, 1.4f, ScaleAnimation.RELATIVE_TO_SELF, 0.5f, ScaleAnimation.RELATIVE_TO_SELF, 0.5f); //漸變動畫 AlphaAnimation alphaAnimation = new AlphaAnimation(1.0f, 0.5f); scaleAnimation.setDuration(800); scaleAnimation.setRepeatCount(Animation.INFINITE); alphaAnimation.setRepeatCount(Animation.INFINITE); as.setDuration(800); as.addAnimation(scaleAnimation); as.addAnimation(alphaAnimation); iv1.startAnimation(as);} |
最外層imageView的動畫
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private void setAnim2() { AnimationSet as = new AnimationSet(true); //縮放動畫，以中心從1.4倍放大到1.8倍 ScaleAnimation scaleAnimation = new ScaleAnimation(1.4f, 1.8f, 1.4f, 1.8f, ScaleAnimation.RELATIVE_TO_SELF, 0.5f, ScaleAnimation.RELATIVE_TO_SELF, 0.5f); //漸變動畫 AlphaAnimation alphaAnimation = new AlphaAnimation(0.5f, 0.1f); scaleAnimation.setDuration(800); scaleAnimation.setRepeatCount(Animation.INFINITE); alphaAnimation.setRepeatCount(Animation.INFINITE); as.setDuration(800); as.addAnimation(scaleAnimation); as.addAnimation(alphaAnimation); iv2.startAnimation(as);} |
效果圖
相比較而言，自定義view的效果更好點，動畫實現起來更方便點。
兩種方式實現的擴散效果介紹完畢，具體項目里還是要按需變動的。
總結
以上所述是小編給大家介紹的Android 實現圓圈擴散水波動畫效果兩種方法，希望對大家有所幫助，如果大家有任何疑問請給我留言，小編會及時回復大家的。在此也非常感謝大家對服務器之家網站的支持！
原文鏈接：https://www.cnblogs.com/taixiang/archive/2018/05/27/9095464.html
