<?xml version="1.0" encoding="utf-8"?>
<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"
    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">

    <TextView
        android:id="@+id/text1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ellipsize="end"
        android:maxLines="2" />

    <Button
        android:id="@+id/btn_showmore"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/text1"
        android:text="show more" />

    <TextView
        android:id="@+id/text2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:visibility="gone" />

    <Button
        android:id="@+id/btn_hidden"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/text2"
        android:text="hidden"
        android:visibility="gone" />
</RelativeLayout>

package com.example.csonezp.showmoredemo;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import butterknife.Bind;
import butterknife.ButterKnife;
import butterknife.OnClick;

public class MainActivity extends AppCompatActivity {
    String text = "据报道，男子沃纳事发时与兄长在巴塔克兰剧院内欣赏演唱会，枪手突然闯入乱枪扫射，当时枪手站在沃纳的兄长身后，并命令沃纳把会场其中一扇门关上。沃纳忆述当时自己双手合十，直视枪手双眼说：“不，因为我兄弟还在里面。”枪手让沃纳的兄长和他离开，随即便把门关上，兄弟二人和其余50名观众通过会场的通风区域逃走。";

    @Bind(R.id.text1)
    TextView textView1;
    @Bind(R.id.text2)
    TextView textView2;
    @Bind(R.id.btn_showmore)
    Button btn_showmore;
    @Bind(R.id.btn_hidden)
    Button btn_hidden;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);
        textView1.setText(text);
        textView2.setText(text);
    }

    @OnClick(R.id.btn_showmore)
    public void showMore() {
        textView1.setVisibility(View.GONE);
        btn_showmore.setVisibility(View.GONE);
        textView2.setVisibility(View.VISIBLE);
        btn_hidden.setVisibility(View.VISIBLE);
    }

    @OnClick(R.id.btn_hidden)
    public void hidden() {
        textView1.setVisibility(View.VISIBLE);
        btn_showmore.setVisibility(View.VISIBLE);
        textView2.setVisibility(View.GONE);
        btn_hidden.setVisibility(View.GONE);
    }


}