<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:orientation="vertical"  android:layout_width="match_parent"  android:layout_height="match_parent">  <TextView    android:id="@+id/content"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:textSize="16sp"    android:maxLines="3"    android:ellipsize="end"/>  <TextView    android:id="@+id/hide_show"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:background="@drawable/btn_showmore"    android:textColor="@color/colorBlue"    android:textSize="16sp"    android:text="顯示更多"    android:padding="0dp"    /></LinearLayout>

//新建java類繼承自LinearLayoutpublic class ShowMoreTextView extends LinearLayout {//  用來標記是否為展開狀態  private int hideOrShow = 0;  private TextView textView;  private TextView button;  public ShowMoreTextView(Context context) {    super(context);  }  public ShowMoreTextView(Context context, AttributeSet attrs) {    super(context, attrs);//    實例化layoutInflater對象，獲取到布局填充服務    LayoutInflater layoutInflater = (LayoutInflater)context.        getSystemService(Context.LAYOUT_INFLATER_SERVICE);//    填充自定義的布局xml文件    layoutInflater.inflate(R.layout.showmore,this);    textView = (TextView)findViewById(R.id.content);    button=(TextView) findViewById(R.id.hide_show);    button.setText("顯示更多");//    隱藏或顯示    hideOrShow();  }//  創建setContent方法為TextView填充內容  public void setContent(String content) {    textView.setText(content);  }  public void hideOrShow() {    button.setOnClickListener(new OnClickListener() {      @Override      public void onClick(View v) {      //由hideOrShow的值確定按鈕和textview的狀態        if (hideOrShow == 0) {          button.setText("收起");          textView.setMaxLines(100);          hideOrShow = 2;        }else if(hideOrShow==2){          button.setText("顯示更多");          textView.setMaxLines(3);          hideOrShow = 1;        }else if(hideOrShow==1){          button.setText("收起");          textView.setMaxLines(100);          hideOrShow=2;        }      }    });  }}

<?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="com.commy.activity.TestActivity">  <com.yunfeng.laojiahenan.view.ShowMoreTextView    android:id="@+id/showmore"    android:layout_width="match_parent"    android:layout_height="wrap_content"/></RelativeLayout>

public class TestActivity extends AppCompatActivity {  private ShowMoreTextView showMoreTextView;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_test);    showMoreTextView=(ShowMoreTextView)findViewById(R.id.showmore);    showMoreTextView.setContent("      There is so much life      I've left to live      And this fire's burning still      When I watch you look at me       I think I could find a way      To stand for every dream      And forsake this solid ground      And give up this fear within      Of what would happen if they end you      I'm in love with you    ");  }}