文本伸缩的实现

效果如上,首先是上面的安全信息部分DetailSafeHolder

public class DetailSafeHolder extends BaseHolder<DetailBean> {    @Bind(R.id.app_detail_safe_iv_arrow)    ImageView mAppDetailSafeIvArrow;    @Bind(R.id.app_detail_safe_pic_container)    LinearLayout mAppDetailSafePicContainer;    @Bind(R.id.app_detail_safe_des_container)    LinearLayout mAppDetailSafeDesContainer;    private View mSafeView;    private boolean isOpen = false;    private int mStart;    private int mEnd;    @Override    public void setContent(DetailBean detailBean) {//添加几个绿色安全图片addPicView(detailBean);//添加安全描述信息addSafeDes(detailBean);    }    @Override    public View getViewInflate() {mSafeView = View.inflate(UiUtil.getContext(), R.layout.item_app_detail_safe, null);ButterKnife.bind(this, mSafeView);//设置箭头的点击监听事件//初始不需要执行伸缩动画toggle(false);mAppDetailSafeIvArrow.setOnClickListener(new View.OnClickListener() {    @Override    public void onClick(View v) {toggle(true);    }});return mSafeView;    }    private void toggle(boolean isAnimator) {//首先需要测量安全信息的宽高mAppDetailSafeDesContainer.measure(View.MeasureSpec.makeMeasureSpec(mAppDetailSafePicContainer.getMeasuredWidth(),View.MeasureSpec.EXACTLY), 0);//动态定义高度int height = mAppDetailSafeDesContainer.getMeasuredHeight();if (isAnimator) {    //需要执行伸缩动画    if (isOpen) {//收缩mStart = height;mEnd = 0;//箭头向下动画ObjectAnimator animator = ObjectAnimator.ofFloat(mAppDetailSafeIvArrow,"rotation",-180,0);animator.setDuration(500);animator.start();    } else {//伸展mStart = 0;mEnd = height;//箭头向上动画ObjectAnimator animator = ObjectAnimator.ofFloat(mAppDetailSafeIvArrow,"rotation",0,180);animator.setDuration(500);animator.start();    }    //开始动画    startAnimation(mStart,mEnd);    isOpen = !isOpen;} else {    //无需伸缩动画    ViewGroup.LayoutParams params = mAppDetailSafeDesContainer.getLayoutParams();    if (isOpen) {//收缩params.height = 0;    } else {//伸展params.height = height;    }    mAppDetailSafeDesContainer.setLayoutParams(params);}    }    private void startAnimation(int start,int end) {ValueAnimator animator = ValueAnimator.ofObject(new FloatEvaluator(),start,end);animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {    @Override    public void onAnimationUpdate(ValueAnimator animation) {float animatedValue = (float) animation.getAnimatedValue();ViewGroup.LayoutParams params = mAppDetailSafeDesContainer.getLayoutParams();params.height = (int) animatedValue;mAppDetailSafeDesContainer.setLayoutParams(params);mAppDetailSafeDesContainer.invalidate();    }});animator.setDuration(500);animator.start();    }    private void addSafeDes(DetailBean detailBean) {for (DetailBean.SafeBean safeBean : detailBean.safe) {    LinearLayout desLayout = new LinearLayout(UiUtil.getContext());    desLayout.setGravity(Gravity.CENTER);    //添加安全描述信息里的图片部分    ImageView iv = new ImageView(UiUtil.getContext());    String url = Constant.SERVER_IMAGEURL + safeBean.safeDesUrl;    Picasso.with(UiUtil.getContext()).load(url).into(iv);    desLayout.addView(iv);    //添加文字描述信息部分    TextView tv = new TextView(UiUtil.getContext());    tv.setText(safeBean.safeDes);    desLayout.addView(tv);    LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,    ViewGroup.LayoutParams.WRAP_CONTENT);    param.leftMargin = 4;    //添加到安全信息容器里    mAppDetailSafeDesContainer.addView(desLayout,param);}    }    private void addPicView(DetailBean detailBean) {for (DetailBean.SafeBean safeBean : detailBean.safe) {    LinearLayout picLayout = new LinearLayout(UiUtil.getContext());    picLayout.setGravity(Gravity.CENTER);    ImageView picView = new ImageView(UiUtil.getContext());    String url = Constant.SERVER_IMAGEURL + safeBean.safeUrl;    Picasso.with(UiUtil.getContext()).load(url).into(picView);    picLayout.addView(picView);    LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,    ViewGroup.LayoutParams.WRAP_CONTENT);    param.leftMargin = 4;    mAppDetailSafePicContainer.addView(picLayout, param);}    }}

DetailSafeHolder需要填充的布局文件item_app_detail_safe.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"              android:layout_width="match_parent"              android:layout_height="match_parent"              android:orientation="vertical">    <!-- 上面部分 -->    <RelativeLayout        android:layout_width="match_parent"        android:layout_height="wrap_content">        <ImageView            android:id="@+id/app_detail_safe_iv_arrow"            android:layout_width="15dp"            android:layout_height="15dp"            android:layout_alignParentRight="true"            android:layout_centerVertical="true"            android:layout_marginRight="15dp"            android:src="@drawable/arrow_down"/>        <!-- 图片容器 -->        <LinearLayout            android:id="@+id/app_detail_safe_pic_container"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_below="@id/app_detail_des_iv_arrow"            android:orientation="horizontal"            android:paddingBottom="5dp"            android:paddingLeft="10dp"            android:paddingTop="5dp">        </LinearLayout>    </RelativeLayout>    <!-- 下面部分 -->    <LinearLayout        android:id="@+id/app_detail_safe_des_container"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:orientation="vertical">    </LinearLayout></LinearLayout>

下面的描述部分DetailDesHolder部分

public class DetailDesHolder extends BaseHolder<DetailBean> {    @Bind(R.id.app_detail_des_tv_des)    TextView mAppDetailDesTvDes;    @Bind(R.id.app_detail_des_tv_author)    TextView mAppDetailDesTvAuthor;    @Bind(R.id.app_detail_des_iv_arrow)    ImageView mAppDetailDesIvArrow;    private View mDesView;    private int mWidth;    private boolean isOpen = false;    private int mStart;    private int mEnd;    @Override    public void setContent(DetailBean detailBean) {System.out.println("des==" + detailBean.des);mAppDetailDesTvDes.setText(detailBean.des);mAppDetailDesTvAuthor.setText("作者:" + detailBean.author);System.out.println("author==" + detailBean.author);    }    @Override    public View getViewInflate() {mDesView = View.inflate(UiUtil.getContext(), R.layout.item_app_detail_des, null);ButterKnife.bind(this, mDesView);toggle(false);mAppDetailDesTvDes.getViewTreeObserver()  .addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {      @Override      public void onGlobalLayout() {  mWidth = mAppDetailDesTvDes.getMeasuredWidth();  mAppDetailDesTvDes.getViewTreeObserver()    .removeOnGlobalLayoutListener(this);      }  });mAppDetailDesIvArrow.setOnClickListener(new View.OnClickListener() {    @Override    public void onClick(View v) {toggle(true);    }});return mDesView;    }    private void toggle(boolean isAnimator) {//首先需要测量描述信息的宽高mAppDetailDesTvDes.measure(View.MeasureSpec.makeMeasureSpec(mWidth,    View.MeasureSpec.EXACTLY), 0);//动态定义高度int height = mAppDetailDesTvDes.getMeasuredHeight();if (isAnimator) {    //需要执行伸缩动画    if (isOpen) {//收缩mStart = height;mEnd = get7Height();//箭头向下动画ObjectAnimator animator = ObjectAnimator.ofFloat(mAppDetailDesIvArrow, "rotation", -180, 0);animator.setDuration(500);animator.start();    } else {//伸展mStart = get7Height();mEnd = height;//箭头向上动画ObjectAnimator animator = ObjectAnimator.ofFloat(mAppDetailDesIvArrow, "rotation", 0, 180);animator.setDuration(500);animator.start();    }    //开始动画    startAnimation(mStart, mEnd);    isOpen = !isOpen;} else {    //无需伸缩动画    ViewGroup.LayoutParams params = mAppDetailDesTvDes.getLayoutParams();    if (isOpen) {//收缩params.height = 0;    } else {//伸展params.height = height;    }    mAppDetailDesTvDes.setLayoutParams(params);}    }    private int get7Height() {TextView textView = new TextView(UiUtil.getContext());textView.setText(mAppDetailDesTvDes.getText());textView.setLines(7);textView.measure(View.MeasureSpec.makeMeasureSpec(mWidth, View.MeasureSpec.EXACTLY),0);return textView.getMeasuredHeight();    }    private void startAnimation(int start, int end) {ValueAnimator animator = ValueAnimator.ofObject(new FloatEvaluator(), start, end);animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {    @Override    public void onAnimationUpdate(ValueAnimator animation) {float animatedValue = (float) animation.getAnimatedValue();ViewGroup.LayoutParams params = mAppDetailDesTvDes.getLayoutParams();params.height = (int) animatedValue;mAppDetailDesTvDes.setLayoutParams(params);mAppDetailDesTvDes.invalidate();    }});animator.addListener(new Animator.AnimatorListener() {    @Override    public void onAnimationStart(Animator animation) {    }    @Override    public void onAnimationEnd(Animator animation) {//动画结束时,让ScrollView滚到最下面//获取ScrollViewViewParent parent = mAppDetailDesTvDes.getParent();while (parent != null) {    parent = parent.getParent();    if (parent != null && parent instanceof ScrollView) {//找到了ScrollView scrollView = (ScrollView) parent;scrollView.fullScroll(View.FOCUS_DOWN);    }}    }    @Override    public void onAnimationCancel(Animator animation) {    }    @Override    public void onAnimationRepeat(Animator animation) {    }});animator.setDuration(500);animator.start();    }}

填充DetailDesHolder的布局文件item_app_detail_des.xml

<?xml version="1.0" encoding="utf-8"?><FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"             android:layout_width="match_parent"             android:layout_height="match_parent"             android:padding="4dp">    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:background="@android:color/white"        android:orientation="vertical"        android:padding="5dp">        <!-- 简介 -->        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:singleLine="true"            android:text="简介"            android:textColor="@android:color/black"            android:textSize="16sp"/>        <!-- 描述详情区域 -->        <TextView            android:id="@+id/app_detail_des_tv_des"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:layout_marginTop="5dp"            android:text="内容"            android:textColor="@android:color/darker_gray"            android:textSize="14sp"/>        <!-- 作者区域 -->        <RelativeLayout            android:layout_width="match_parent"            android:layout_height="25dp">            <TextView                android:id="@+id/app_detail_des_tv_author"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:layout_centerVertical="true"                android:text="作者 : "                android:textColor="@android:color/darker_gray"                android:textSize="14sp"/>            <ImageView                android:id="@+id/app_detail_des_iv_arrow"                android:layout_width="15dp"                android:layout_height="15dp"                android:layout_alignParentRight="true"                android:layout_centerVertical="true"                android:src="@drawable/arrow_down"/>        </RelativeLayout>    </LinearLayout></FrameLayout>

上面的只是文本伸缩部分的代码片段,仅供参考