属性动画实现平移效果

来源：互联网发布：什么软件字体多编辑：程序博客网时间：2024/04/27 14:37

Android提供了几种动画类型：View Animation 、Drawable Animation 、Property Animation 。View Animation相当简单，不过只能支持简单的缩放、平移、旋转、透明度基本的动画，且有一定的局限性。比如：你希望View有一个颜色的切换动画；你希望可以使用3D旋转动画；你希望当动画停止时，View的位置就是当前的位置；这些View Animation都无法做到。

以3.0版本为界,之前的称之为传统动画,传统动画特点万变不离其宗,宗就是是它刚开始的位置.
之后出了属性动画

需求:
一个button和imageview相邻,点击button,控制imageview的显示和隐藏,并且让imageview从button中隐藏和开启
用传统动画的话可以使用旋转动画并且配以AnimationListener,但是效果不是类似抽屉抽拉的效果

今天我们来用Property Animation实现一个类似抽屉抽拉的效果的动画.

布局文件如下,很简单

<?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"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context=".MainActivity">    <LinearLayout        android:background="@android:color/holo_blue_bright"        android:onClick="llClick"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:gravity="center_vertical"        android:orientation="horizontal">        <ImageView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:src="@drawable/ic_launcher" />        <TextView            android:layout_width="match_parent"            android:layout_height="match_parent"            android:gravity="center"            android:text="click me"            android:textSize="30sp" />    </LinearLayout>    <LinearLayout        android:background="@android:color/holo_green_light"        android:id="@+id/llhiddview"        android:layout_width="match_parent"        android:layout_height="40dp"        android:gravity="center_vertical"        android:orientation="horizontal">        <ImageView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:src="@drawable/ic_launcher" />        <TextView            android:gravity="center"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:text="hidden view"            android:textSize="30sp" />    </LinearLayout></LinearLayout>

activity中

public class MainActivity extends ActionBarActivity {    LinearLayout llhidv;    int hidviewHeight;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        llhidv = (LinearLayout) findViewById(R.id.llhiddview);        float disn = getResources().getDisplayMetrics().density;        hidviewHeight = (int) (disn * 40 + 0.5);        Log.e("lc---", hidviewHeight +"hidviewHeight");    }    public void llClick(View view) {        if (llhidv.getVisibility() == View.GONE) {            Log.e("lc---", llhidv.getVisibility() + "GONE");            open(llhidv);        } else {            Log.e("lc---", llhidv.getVisibility() + "fei gone");            close(llhidv);        }    }    /**     * 关闭--动画     *     * @param view     */    private void close(final View view) {        int origheight = view.getHeight();        Log.e("lc---", origheight + "origheight");        ValueAnimator animator = createDropAnimator(view, origheight, 0);        animator.addListener(new AnimatorListenerAdapter() {            @Override            public void onAnimationEnd(Animator animation) {                view.setVisibility(View.GONE);                Log.e("lc---", "" + "close");            }        });        animator.start();    }    /**     * 打开--动画     *     * @param view     */    private void open(View view) {        view.setVisibility(View.VISIBLE);        ValueAnimator animator = createDropAnimator(view, 0, hidviewHeight);        Log.e("lc---", hidviewHeight +"hidviewHeight---open");        animator.start();    }    private ValueAnimator createDropAnimator(final View view, int start, int end) {        ValueAnimator animator = ValueAnimator.ofInt(start, end);        animator.addUpdateListener(                new ValueAnimator.AnimatorUpdateListener() {                    @Override                    public void onAnimationUpdate(ValueAnimator valueAnimator) {                        //   int value = (Integer)valueAnimator.getAnimatedValue();                        int value = (Integer) valueAnimator.getAnimatedValue();// 得到的值                        ViewGroup.LayoutParams layoutParams = view.getLayoutParams();//                        layoutParams.height = Float.floatToIntBits(value);                        layoutParams.height = value;                        view.setLayoutParams(layoutParams);                    }                }        );        return animator;    }}

除此之外可能的问题,如果imageview的高度不是固定为40,怎么一开始就获取imageview的高度呢?
要知道view.getHeight()方法是view在绘制完成之后才会取得view的真是高度哦,view初始化的时候宽高可都是0哦!!!
http://blog.csdn.net/listening_music/article/details/7210146
http://blog.csdn.net/nailsoul/article/details/25909313
好的,解决完毕.

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