水波纹过渡特效

来源：互联网发布：数据保护系统破解编辑：程序博客网时间：2024/04/28 22:52

先看效果图：

水波纹

我们先创建一个UIUtils，转换一些单位：

package com.lgl.test;import android.content.Context;import android.util.DisplayMetrics;import android.view.WindowManager;public class UiUtils {    static public int getScreenWidthPixels(Context context) {        DisplayMetrics dm = new DisplayMetrics();        ((WindowManager) context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay()                .getMetrics(dm);        return dm.widthPixels;    }    static public int dipToPx(Context context, int dip) {        return (int) (dip * getScreenDensity(context) + 0.5f);    }    static public float getScreenDensity(Context context) {        try {            DisplayMetrics dm = new DisplayMetrics();            ((WindowManager) context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay()                    .getMetrics(dm);            return dm.density;        } catch (Exception e) {            return DisplayMetrics.DENSITY_DEFAULT;        }    }}

然后写一个WaterRippleView类继承View

package com.lgl.test;import android.content.Context;import android.graphics.Canvas;import android.graphics.DrawFilter;import android.graphics.Paint;import android.graphics.Paint.Style;import android.graphics.PaintFlagsDrawFilter;import android.util.AttributeSet;import android.view.View;public class WaterRippleView extends View {    // 波纹颜色    private static final int WAVE_PAINT_COLOR = 0x880000aa;    // y = Asin(wx+b)+h    private static final float STRETCH_FACTOR_A = 20;    private static final int OFFSET_Y = 0;    // 第一条水波移动速度    private static final int TRANSLATE_X_SPEED_ONE = 7;    // 第二条水波移动速度    private static final int TRANSLATE_X_SPEED_TWO = 5;    private float mCycleFactorW;    private int mTotalWidth, mTotalHeight;    private float[] mYPositions;    private float[] mResetOneYPositions;    private float[] mResetTwoYPositions;    private int mXOffsetSpeedOne;    private int mXOffsetSpeedTwo;    private int mXOneOffset;    private int mXTwoOffset;    private Paint mWavePaint;    private DrawFilter mDrawFilter;    public WaterRippleView(Context context, AttributeSet attrs) {        super(context, attrs);        // 将dp转化为px，用于控制不同分辨率上移动速度基本一致        mXOffsetSpeedOne = UiUtils.dipToPx(context, TRANSLATE_X_SPEED_ONE);        mXOffsetSpeedTwo = UiUtils.dipToPx(context, TRANSLATE_X_SPEED_TWO);        // 初始绘制波纹的画笔        mWavePaint = new Paint();        // 去除画笔锯齿        mWavePaint.setAntiAlias(true);        // 设置风格为实线        mWavePaint.setStyle(Style.FILL);        // 设置画笔颜色        mWavePaint.setColor(WAVE_PAINT_COLOR);        mDrawFilter = new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG                | Paint.FILTER_BITMAP_FLAG);    }    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        // 从canvas层面去除绘制时锯齿        canvas.setDrawFilter(mDrawFilter);        resetPositonY();        for (int i = 0; i < mTotalWidth; i++) {            // 减400只是为了控制波纹绘制的y的在屏幕的位置，大家可以改成一个变量，然后动态改变这个变量，从而形成波纹上升下降效果            // 绘制第一条水波纹            canvas.drawLine(i, mTotalHeight - mResetOneYPositions[i] - 400, i,                    mTotalHeight, mWavePaint);            // 绘制第二条水波纹            canvas.drawLine(i, mTotalHeight - mResetTwoYPositions[i] - 400, i,                    mTotalHeight, mWavePaint);        }        // 改变两条波纹的移动点        mXOneOffset += mXOffsetSpeedOne;        mXTwoOffset += mXOffsetSpeedTwo;        // 如果已经移动到结尾处，则重头记录        if (mXOneOffset >= mTotalWidth) {            mXOneOffset = 0;        }        if (mXTwoOffset > mTotalWidth) {            mXTwoOffset = 0;        }        // 引发view重绘，一般可以考虑延迟20-30ms重绘，空出时间片        postInvalidate();    }    private void resetPositonY() {        // mXOneOffset代表当前第一条水波纹要移动的距离        int yOneInterval = mYPositions.length - mXOneOffset;        // 使用System.arraycopy方式重新填充第一条波纹的数据        System.arraycopy(mYPositions, mXOneOffset, mResetOneYPositions, 0,                yOneInterval);        System.arraycopy(mYPositions, 0, mResetOneYPositions, yOneInterval,                mXOneOffset);        int yTwoInterval = mYPositions.length - mXTwoOffset;        System.arraycopy(mYPositions, mXTwoOffset, mResetTwoYPositions, 0,                yTwoInterval);        System.arraycopy(mYPositions, 0, mResetTwoYPositions, yTwoInterval,                mXTwoOffset);    }    @Override    protected void onSizeChanged(int w, int h, int oldw, int oldh) {        super.onSizeChanged(w, h, oldw, oldh);        // 记录下view的宽高        mTotalWidth = w;        mTotalHeight = h;        // 用于保存原始波纹的y值        mYPositions = new float[mTotalWidth];        // 用于保存波纹一的y值        mResetOneYPositions = new float[mTotalWidth];        // 用于保存波纹二的y值        mResetTwoYPositions = new float[mTotalWidth];        // 将周期定为view总宽度        mCycleFactorW = (float) (2 * Math.PI / mTotalWidth);        // 根据view总宽度得出所有对应的y值        for (int i = 0; i < mTotalWidth; i++) {            mYPositions[i] = (float) (STRETCH_FACTOR_A                    * Math.sin(mCycleFactorW * i) + OFFSET_Y);        }    }}

使用时：

<com.lgl.test.WaterRippleView   android:layout_width="fill_parent"   android:layout_height="fill_parent"   />

然后你就可以绑定在布局上就可以使用了

Demo下载地址：http://download.csdn.net/detail/qq_26787115/9384803

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