Android實現波浪效果 - WaveView

實現

WaveView的屬性

實現思路

設想我們有一個畫好波形的圖片，那么我們只需要用這張圖片填充（X軸方向重復，Y軸方向延伸）整個View，然后水平移動圖片，就可以得到波浪效果了。

所以要做的事很簡單：繪制一個波形圖，填充到View里，移動波形圖。

1. 繪制初始波形

private void createShader() {
    ...

    Bitmap bitmap = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap);

    // Draw default waves into the bitmap
    // y=Asin(ωx+φ)+h
    float waveX1 = 0;
    final float wave2Shift = mDefaultWaveLength / 4;
    final float endX = getWidth();
    final float endY = getHeight();

    ...

    while (waveX1 < endX) {
        double wx = waveX1 * mDefaultAngularFrequency;
        int startY = (int) (mDefaultWaterLevel + mDefaultAmplitude * Math.sin(wx));

        // draw bottom wave with the alpha 40
        canvas.drawLine(waveX1, startY, waveX1, endY, wavePaint1);
        // draw top wave with the alpha 60
        float waveX2 = (waveX1 + wave2Shift) % endX;
        canvas.drawLine(waveX2, startY, waveX2, endY, wavePaint2);

        waveX1++;
    }

    // use the bitamp to create the shader
    mWaveShader = new BitmapShader(bitmap, Shader.TileMode.REPEAT, Shader.TileMode.CLAMP);
    mViewPaint.setShader(mWaveShader);
}

項目主頁：http://www.baiduhome.net/lib/view/home/1442316885727