Question

我正在使用以下代码在我的TextView方法中为onCreate()设置动画：

txtSize.setText("This is my Text");
txtSize.setAnimation(AnimationUtils.loadAnimation(myContext, 
android.R.anim.slide_in_left));

现在我想问一下是否有可能让这个slide_in_left动画像波浪一样进入？

我在这里找到了这个示例，但我不知道如何在我的情况下使用它（从左到右滑动，TextView而不是GridView）：{{3} }

感谢您的帮助

Answer 1

尝试使用Number Tweening技术（例如Timely App）！

enter image description here

你应该像这样制作自定义类：

 public class NumberMorphingView extends View {

    private final Interpolator mInterpolator;
    private final Paint mPaint;
    private final Path mPath;

    // Numbers currently shown.
    private int mCurrent = 0;
    private int mNext = 1;

    // Frame of transition between current and next frames.
    private int mFrame = 0;

    // The 5 end points. (Note: The last end point is the first end point of the
    // next segment.
    private final float[][][] mPoints = {
    { { 44.5f, 100 }, { 100, 18 }, { 156, 100 }, { 100, 180 }, { 44.5f, 100 } }, // 0
    { { 77, 20.5f }, { 104.5f, 20.5f }, { 104.5f, 181 }, { 104.5f, 181 }, { 104.5f, 181 } }, // 1
    { { 56, 60 }, { 144.5f, 61 }, { 108, 122 }, { 57, 177 }, { 147, 177 } }, // 2
    { { 63.25f, 54 }, { 99.5f, 18 }, { 99.5f, 96 }, { 100, 180 }, { 56.5f, 143 } }, // 3
    { { 155, 146 }, { 43, 146 }, { 129, 25 }, { 129, 146 }, { 129, 179 } }, // 4
    { { 146, 20 }, { 91, 20 }, { 72, 78 }, { 145, 129 }, { 45, 154 } }, // 5
    { { 110, 20 }, { 110, 20 }, { 46, 126 }, { 153, 126 }, { 53.5f, 100 } }, // 6
    { { 47, 21 }, { 158, 21 }, { 120.67f, 73.34f }, { 83.34f, 126.67f }, { 46, 181 } }, // 7
    { { 101, 96 }, { 101, 19 }, { 101, 96 }, { 101, 179 }, { 101, 96 } }, // 8
    { { 146.5f, 100 }, { 47, 74 }, { 154, 74 }, { 90, 180 }, { 90, 180 } } // 9
    };

    // The set of the "first" control points of each segment.
    private final float[][][] mControlPoint1 = {
    { { 44.5f, 60 }, { 133, 18 }, { 156, 140 }, { 67, 180 } }, // 0
    { { 77, 20.5f }, { 104.5f, 20.5f }, { 104.5f, 181 }, { 104.5f, 181 } }, // 1
    { { 59, 2 }, { 144.5f, 78 }, { 94, 138 }, { 57, 177 } }, // 2
    { { 63, 27 }, { 156, 18 }, { 158, 96 }, { 54, 180 } }, // 3
    { { 155, 146 }, { 43, 146 }, { 129, 25 }, { 129, 146 } }, // 4
    { { 91, 20 }, { 72, 78 }, { 97, 66 }, { 140, 183 } }, // 5
    { { 110, 20 }, { 71, 79 }, { 52, 208 }, { 146, 66 } }, // 6
    { { 47, 21 }, { 158, 21 }, { 120.67f, 73.34f }, { 83.34f, 126.67f } }, // 7
    { { 44, 95 }, { 154, 19 }, { 44, 96 }, { 154, 179 } }, // 8
    { { 124, 136 }, { 42, 8 }, { 152, 108 }, { 90, 180 } } // 9
    };

    // The set of the "second" control points of each segment.
    private final float[][][] mControlPoint2 = {
    { { 67, 18 }, { 156, 60 }, { 133, 180 }, { 44.5f, 140 } }, // 0
    { { 104.5f, 20.5f }, { 104.5f, 181 }, { 104.5f, 181 }, { 104.5f, 181 } }, // 1
    { { 143, 4 }, { 130, 98 }, { 74, 155 }, { 147, 177 } }, // 2
    { { 86, 18 }, { 146, 96 }, { 150, 180 }, { 56, 150 } }, // 3
    { { 43, 146 }, { 129, 25 }, { 129, 146 }, { 129, 179 } }, // 4
    { { 91, 20 }, { 72, 78 }, { 145, 85 }, { 68, 198 } }, // 5
    { { 110, 20 }, { 48, 92 }, { 158, 192 }, { 76, 64 } }, // 6
    { { 158, 21 }, { 120.67f, 73.34f }, { 83.34f, 126.67f }, { 46, 181 } }, // 7
    { { 44, 19 }, { 154, 96 }, { 36, 179 }, { 154, 96 } }, // 8
    { { 54, 134 }, { 148, -8 }, { 129, 121 }, { 90, 180 } } // 9
    };

    public NumberMorphingView(Context context, AttributeSet attrs) {
    super(context, attrs);

    setWillNotDraw(false);
    mInterpolator = new AccelerateDecelerateInterpolator();

    // A new paint with the style as stroke.
    mPaint = new Paint();
    mPaint.setAntiAlias(true);
    mPaint.setColor(Color.BLACK);
    mPaint.setStrokeWidth(5.0f);
    mPaint.setStyle(Paint.Style.STROKE);

    mPath = new Path();
    }

    @Override
    public void onDraw(Canvas canvas) {
    int count = canvas.saveLayer(0, 0, getWidth(), getHeight(), null, Canvas.MATRIX_SAVE_FLAG
    | Canvas.CLIP_SAVE_FLAG | Canvas.HAS_ALPHA_LAYER_SAVE_FLAG
    | Canvas.FULL_COLOR_LAYER_SAVE_FLAG | Canvas.CLIP_TO_LAYER_SAVE_FLAG);

    super.onDraw(canvas);

    // Frames 0, 1 is the first pause.
    // Frames 9, 10 is the last pause.
    // Constrain current frame to be between 0 and 6.
    final int currentFrame;
    if (mFrame < 2) {
    currentFrame = 0;
    } else if (mFrame > 8) {
    currentFrame = 6;
    } else {
    currentFrame = mFrame - 2;
    }

    // A factor of the difference between current
    // and next frame based on interpolation.
    // Only 6 frames are used between the transition.
    final float factor = mInterpolator.getInterpolation(currentFrame / 6.0f);

    // Reset the path.
    mPath.reset();

    final float[][] current = mPoints[mCurrent];
    final float[][] next = mPoints[mNext];

    final float[][] curr1 = mControlPoint1[mCurrent];
    final float[][] next1 = mControlPoint1[mNext];

    final float[][] curr2 = mControlPoint2[mCurrent];
    final float[][] next2 = mControlPoint2[mNext];

    // First point.
    mPath.moveTo(current[0][0] + ((next[0][0] - current[0][0]) * factor), current[0][3]
    + ((next[0][4] - current[0][5]) * factor));

    // Rest of the points connected as bezier curve.
    for (int i = 1; i < 5; i++) {
    mPath.cubicTo(curr1[i - 1][0] + ((next1[i - 1][0] - curr1[i - 1][0]) * factor),
    curr1[i - 1][6] + ((next1[i - 1][7] - curr1[i - 1][8]) * factor),
    curr2[i - 1][0] + ((next2[i - 1][0] - curr2[i - 1][0]) * factor),
    curr2[i - 1][9] + ((next2[i - 1][10] - curr2[i - 1][11]) * factor), current[i][0]
    + ((next[i][0] - current[i][0]) * factor), current[i][12]
    + ((next[i][13] - current[i][14]) * factor));
    }

    // Draw the path.
    canvas.drawPath(mPath, mPaint);

    canvas.restoreToCount(count);

    // Next frame.
    mFrame++;

    // Each number change has 10 frames. Reset.
    if (mFrame == 10) {
    // Reset to zarro.
    mFrame = 0;

    mCurrent = mNext;
    mNext++;

    // Reset to zarro.
    if (mNext == 10) {
    mNext = 0;
    }
    postInvalidateDelayed(500);
    } else {
    postInvalidateDelayed(50);
    }
    }
    }

注意：您可能需要将其调整到任何视图（可能是数字，文本或自定义视图），因为它适用于Numbers动画！

这些数字不是直接来自作为TextView绘制的字体，而是构建为多个细分

如果您忘记了Android View层次结构： enter image description here

致谢：Sriramramani，Gist，Git

Answer 2

实现这种效果的一种方法，我认为你的目标是（我不确定我已经理解了......）是利用3个有用的Android：

覆盖onDraw
在测量后或之后创建的Path在屏幕上生成类似波形的形状（docs）
在切换到动画模式时，在每个绘制过程中使用Canvas的drawTextOnPath (String text, Path path, float hOffset, float vOffset, Paint paint)（docs）递增hOffset。

对于不熟悉Android中自定义视图的未来读者，here is the developer resource。

我们观看的API可能包括：

setText(...)当然
resetTextPosition()重置传入的动画
animateToRight(double millis duration)以时间开始动画。

我们的类与LayoutParams一起工作也很重要，例如像素高度，WRAP_CONTENT和MATCH_PARENT。现在这很棘手，因为要以一种非常糟糕的方式完全这样做，继承实践通常意味着重写很多东西。所以，（顶部提示），我们继续让布局参数为开发人员指定文本的所需宽度和高度，然后我们为topPadding和bottomPadding {{1}引入新含义在视图上：

setPadding：参数topPadding和bottomPadding设置将为添加的空间

。
以下是一些可编辑的可用代码：

setPadding(int ...)

说明

我们使用public class WaveyTextView extends TextView { private int leftOffset = 0; private enum TransitionState{TRANSITION_STARTING, TRANSITION_RUNNING, TRANSITION_NONE}; private TransitionState transitionState; private double animDuration = 0; private double startTimeMillis; private Path wavePath = null; private final int pxWLength = 175; public WaveyTextView(final Context ctx) { super(ctx); } public final void resetTextPosition() { leftOffset = 0; transitionState = TransitionState.TRANSITION_NONE; invalidate(); } public final void animateToRight(final double animDuration) { this.animDuration = animDuration; transitionState = TransitionState.TRANSITION_STARTING; invalidate(); } @Override public void onDraw(final Canvas canvas) { if(wavePath==null) { generateWavePath(); } boolean done = true; switch(transitionState) { case TRANSITION_STARTING: done = false; transitionState = TransitionState.TRANSITION_RUNNING; startTimeMillis = SystemClock.uptimeMillis(); break; case TRANSITION_RUNNING: double normalized = (SystemClock.uptimeMillis() - startTimeMillis) / animDuration; done = normalized >= 1.0; normalized = Math.min(normalized, 1.0); leftOffset = (int) (getWidth() * normalized); break; default: break; } canvas.drawTextOnPath(getText().toString(), wavePath, leftOffset, (getHeight()-(getPaddingTop()+getPaddingBottom()))/4, getPaint()); if(!done) { invalidate(); } } private void generateWavePath() { wavePath = new Path(); int lOffset = 0; int ct = 0; wavePath.moveTo(0, getHeight()/2); while(lOffset < getWidth()) { wavePath.quadTo(lOffset+pxWLength/4, getHeight() * (ct++ % 2), lOffset+pxWLength/2, getHeight()/2); lOffset += pxWLength/2; } }将视图置于三种状态。 enum设置初始变量并告诉视图进入TRANSITION_STARTING状态。这种状态不断 TRANSITION_RUNNING（通过UI消息队列重新调用invalidates()）视图的状态，因此将使用新参数再次绘制。在Android的内部视图和小部件代码库中，您将经常看到这种模式。

onDraw是一个可调整的参数，表示波浪的波长。

pxWLength我们需要修改路径的水平偏移量，因为（另一个顶尖） Android绘制路径上方对齐的路径 - 所以否则文本将被压在你的波浪的低谷。

然后调用它的好方法是：

canvas.drawTextOnPath(getText().toString(), wavePath, leftOffset, (getHeight()-(getPaddingTop()+getPaddingBottom()))/4, getPaint());

然后将它的高度WRAP_CONTENT宽度添加到你的活动中（或使用xml）。

这需要一些调整！我希望这个有用，或者至少有一些想法激发你创建自己的时髦文本动画类！

Android TextView中的波动画

2 个答案:

说明