为View设置左右切换动画

本文同步自

问题:

近期的需求中，碰到了一个view切换动画的需求。要实现的是点击按钮，从左到右滑动view，左边的view消失，右边的view出现。有点像文字跑马灯的效果，不过这次滚动的是view，具体看截图效果。

 

实现思路:

晚上在家写了一个比较low的实现方案，参考的思路是banner轮播的思路，用viewpager来进行view的切换。大致效果也还行，只不过觉得代码量太多，使用比较麻烦。我就是想给两个view加上可以切换动画的效果，就要写那么多的代码，感觉不划算。只好放弃此方案。

随后想到了swipeview,发现这是一个挺好的点，可以从这里入手。经过对swipemenulayout代码的阅读分析以及测试实践。得出了以下的解决方案。

自定义slidelayout.java

public class slidelayout extends viewgroup {
    private static final string tag = "slidelayout";
    private int mheight;
    private view mcontentview;
    private view mrightview;
    private boolean isanimation = false;

    public slidelayout(context context) {
        this(context, null);
    }

    public slidelayout(context context, attributeset attrs) {
        this(context, attrs, 0);
    }

    public slidelayout(context context, attributeset attrs, int defstyleattr) {
        super(context, attrs, defstyleattr);
    }

    @override
    protected void onmeasure(int widthmeasurespec, int heightmeasurespec) {
        //log.d(tag, "onmeasure() called with: " + "widthmeasurespec = [" + widthmeasurespec + "], heightmeasurespec = [" + heightmeasurespec + "]");
        super.onmeasure(widthmeasurespec, heightmeasurespec);
        mheight = 0;
        int contentwidth = 0;
        int childcount = getchildcount();

        final boolean measurematchparentchildren = measurespec.getmode(heightmeasurespec) != measurespec.exactly;
        boolean isneedmeasurechildheight = false;

        for (int i = 0; i < childcount; i++) {
            view childview = getchildat(i);
            if (childview.getvisibility() != gone) {
                measurechild(childview, widthmeasurespec, heightmeasurespec);
                final marginlayoutparams lp = (marginlayoutparams) childview.getlayoutparams();
                mheight = math.max(mheight, childview.getmeasuredheight()/* + lp.topmargin + lp.bottommargin*/);
                if (measurematchparentchildren && lp.height == layoutparams.match_parent) {
                    isneedmeasurechildheight = true;
                }
                if (i == 0) {
                    mcontentview = childview;
                    contentwidth = childview.getmeasuredwidth();
                } else {
                    mrightview = childview;
                }
            }
        }
        setmeasureddimension(getpaddingleft() + getpaddingright() + contentwidth,
                mheight + getpaddingtop() + getpaddingbottom());//宽度取第一个item(content)的宽度
        if (isneedmeasurechildheight) {//如果子view的height有matchparent属性的，设置子view高度
            forceuniformheight(childcount, widthmeasurespec);
        }
    }

    @override
    public layoutparams generatelayoutparams(attributeset attrs) {
        return new marginlayoutparams(getcontext(), attrs);
    }

    /**
     * 给matchparent的子view设置高度
     *
     * @param count
     * @param widthmeasurespec
     * @see android.widget.linearlayout# 同名方法
     */
    private void forceuniformheight(int count, int widthmeasurespec) {
        // pretend that the linear layout has an exact size. this is the measured height of
        // ourselves. the measured height should be the max height of the children, changed
        // to accommodate the heightmeasurespec from the parent
        int uniformmeasurespec = measurespec.makemeasurespec(getmeasuredheight(),
                measurespec.exactly);//以父布局高度构建一个exactly的测量参数
        for (int i = 0; i < count; ++i) {
            final view child = getchildat(i);
            if (child.getvisibility() != gone) {
                marginlayoutparams lp = (marginlayoutparams) child.getlayoutparams();
                if (lp.height == layoutparams.match_parent) {
                    // temporarily force children to reuse their old measured width
                    int oldwidth = lp.width;//measurechildwithmargins 这个函数会用到宽，所以要保存一下
                    lp.width = child.getmeasuredwidth();
                    // remeasure with new dimensions
                    measurechildwithmargins(child, widthmeasurespec, 0, uniformmeasurespec, 0);
                    lp.width = oldwidth;
                }
            }
        }
    }

    @override
    protected void onlayout(boolean changed, int l, int t, int r, int b) {
        //log.e(tag, "onlayout() called with: " + "changed = [" + changed + "], l = [" + l + "], t = [" + t + "], r = [" + r + "], b = [" + b + "]");
        int childcount = getchildcount();
        int left = 0 + getpaddingleft();
        for (int i = 0; i < childcount; i++) {
            view childview = getchildat(i);
            if (childview.getvisibility() != gone) {
                if (i == 0) {//第一个子view是内容 宽度设置为全屏
                    childview.layout(left, getpaddingtop(), left + childview.getmeasuredwidth(), getpaddingtop() + childview.getmeasuredheight());
                    left = left + childview.getmeasuredwidth();
                } else {
                    childview.layout(left, getpaddingtop(), left + childview.getmeasuredwidth(), getpaddingtop() + childview.getmeasuredheight());
                    left = left + childview.getmeasuredwidth();
                }
            }
        }
        //log.d(tag, "onlayout() called with: " + "maxscrollgap = [" + maxscrollgap + "], l = [" + l + "], t = [" + t + "], r = [" + r + "], b = [" + b + "]");
    }

    public void slideleft(long duration) {
        if (isanimation) {
            return;
        }
        animatorset animatorset = new animatorset();
        final objectanimator objectanimator1 = objectanimator.offloat(mcontentview, "translationx", 0, -mcontentview.getmeasuredwidth());
        final objectanimator objectanimator2 = objectanimator.offloat(mrightview, "translationx", 0, -mcontentview.getmeasuredwidth());
        animatorset.playtogether(objectanimator1, objectanimator2);
        animatorset.addlistener(new animatorlisteneradapter() {
            @override
            public void onanimationstart(animator animation) {
                super.onanimationstart(animation);
                isanimation = true;
            }

            @override
            public void onanimationend(animator animation) {
                super.onanimationend(animation);
                isanimation = false;
            }
        });
        animatorset.setduration(duration);
        animatorset.start();
    }

    public void slideright(long duration) {
        if (isanimation) {
            return;
        }
        animatorset animatorset = new animatorset();
        final objectanimator objectanimator1 = objectanimator.offloat(mcontentview, "translationx", -mcontentview.getmeasuredwidth(), 0);
        final objectanimator objectanimator2 = objectanimator.offloat(mrightview, "translationx", -mcontentview.getmeasuredwidth(), 0);
        animatorset.playtogether(objectanimator1, objectanimator2);
        animatorset.addlistener(new animatorlisteneradapter() {
            @override
            public void onanimationstart(animator animation) {
                super.onanimationstart(animation);
                isanimation = true;
            }

            @override
            public void onanimationend(animator animation) {
                super.onanimationend(animation);
                isanimation = false;
            }
        });
        animatorset.setduration(duration);
        animatorset.start();
    }
}

接着看看如何使用，调用方式。

<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".mainactivity">


    <linearlayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <button
            android:id="@+id/btn_start"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="向左滑动" />

        <button
            android:id="@+id/btn_start2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="向右滑动" />
    </linearlayout>


    <me.star.animator.slidelayout
        android:id="@+id/container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margintop="10dp"
        android:orientation="horizontal">

        <textview
            android:id="@+id/btn_show"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@color/coloraccent"
            android:padding="4dp"
            android:text="展示1"
            android:textsize="20sp"
            android:visibility="visible" />

        <textview
            android:id="@+id/btn_show2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@android:color/holo_green_light"
            android:padding="4dp"
            android:text="展示2"
            android:textsize="20sp" />

    </me.star.animator.slidelayout>


</linearlayout>

@override
    protected void oncreate(bundle savedinstancestate) {
        super.oncreate(savedinstancestate);
        setcontentview(r.layout.activity_main);
        btnshow = findviewbyid(r.id.btn_show);
        btnshow2 = findviewbyid(r.id.btn_show2);
        btnstart = findviewbyid(r.id.btn_start);
        btnstart2 = findviewbyid(r.id.btn_start2);
        container = findviewbyid(r.id.container);

        btnstart.setonclicklistener(new view.onclicklistener() {
            @override
            public void onclick(view v) {
                container.slideleft(3000);
            }
        });

        btnstart2.setonclicklistener(new view.onclicklistener() {
            @override
            public void onclick(view v) {
                container.slideright(3000);
            }
        });
    }

其他相关:

看到泡网上有一个为view和activity设置左右切换动画的文章

代码下载:

链接:https://pan.baidu.com/s/1tg7-ejysozqegu-fqy4how 密码:c8q8