几句代码搞定ExpandableTextView

本例是直接用TextView.setMaxLines(Integer.MAX_VALUE);
先看效果图

先看activity_main.xml
很简单的布局，可以整一个自己需要的布局

<RelativeLayout
    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"
    tools:context="com.example.huangqihua.expandtextview.MainActivity">

    <ScrollView android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="#EFEFEF"
                android:focusableInTouchMode="true"
                android:gravity="center"
        >
        <TextView
            android:id="@+id/expand_text"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:ellipsize="end"
            android:paddingBottom="0dp"
            android:paddingLeft="5dp"
            android:paddingRight="30dp"
            android:lineSpacingExtra="5dp"
            android:maxLines="1"
            android:text="Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!Hello World!"/>
    ScrollView>

    <ImageView
        android:id="@+id/expand_image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="2dp"
        android:layout_marginRight="14dp"
        android:layout_alignParentRight="true"
        android:background="@drawable/class_feed_expand_image_tip_open"/>

RelativeLayout>

再看MainActivity

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

    private ImageView mExpandImage;
    private TextView mExpandText;

    private boolean bExpand; //



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mExpandText = (TextView) findViewById(R.id.expand_text);

        mExpandImage = (ImageView) findViewById(R.id.expand_image);
        assert mExpandImage != null;
        mExpandImage.setOnClickListener(this);

    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.expand_image:
                if (!bExpand){
                    mExpandText.setMaxLines(Integer.MAX_VALUE);
                }else {
                    mExpandText.setMaxLines(1);
                }
                doAnimate();
                bExpand = !bExpand;
                break;
        }
    }

    private void doAnimate() {
        ValueAnimator animator = null;
        if (!bExpand) {
            animator = ObjectAnimator.ofFloat(mExpandImage, "rotation", 0, 180);
        } else {
            animator = ObjectAnimator.ofFloat(mExpandImage, "rotation", 180, 0);
        }
        animator.setDuration(300);
        animator.start();

    }
}