LayoutTransition介绍

首先看一个效果图：

XML布局如下：

<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="com.xbxzc.layouttransition.MainActivity">    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:orientation="horizontal">        <Button            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:onClick="addButton"            android:text="添加Button"/>        <Button            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:onClick="removeButton"            android:text="删除Button"/>    </LinearLayout>    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:id="@+id/myLinearLayout"        android:animateLayoutChanges="true"        android:orientation="vertical">    </LinearLayout></LinearLayout>

其中有一个属性android:animateLayoutChanges="true 添加了以后会在生成Layout的时候添加默认的动画效果

Activity:

public class MainActivity extends AppCompatActivity {    LinearLayout mLinearLayout;    int mark=0;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        mLinearLayout= (LinearLayout) findViewById(R.id.myLinearLayout);    }    public void addButton(View view) {        mark++;        Button button=new Button(this);        button.setText("小苹果"+mark);        LinearLayout.LayoutParams params=new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,                ViewGroup.LayoutParams.WRAP_CONTENT);        mLinearLayout.addView(button,params);    }    public void removeButton(View view) {        if (mark>0){            //移除第一个View            mLinearLayout.removeViewAt(0);        }    }}

LayoutTransition动画演示

 //初始化布局动画        mTransition=new LayoutTransition();        mLinearLayout.setLayoutTransition(mTransition);        //设置布局动画效果        //view出现动画        ObjectAnimator animator=ObjectAnimator.ofFloat(null,"rotationY",90F,0F).                setDuration(mTransition.getDuration(LayoutTransition.APPEARING));        mTransition.setAnimator(LayoutTransition.APPEARING,animator);        //View消失动画        ObjectAnimator animator2 = ObjectAnimator.ofFloat(null, "rotationX", 0F, 90F, 0F).        setDuration(mTransition.getDuration(LayoutTransition.DISAPPEARING));        mTransition.setAnimator(LayoutTransition.DISAPPEARING, animator2);

通过设置了动画以后，显示效果如下：