Zi 字媒體

示範 XML xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" > <TextView android:id="@+id/t1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="TextView" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" /> android.support.constraint.ConstraintLayout> JAVA public class MainActivity extends AppCompatActivity{ TextView t1; String s="Ihavaanappleandtwoeggsandthreecandiesapple";//目標是印出第一個apple String s2; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); t1=(TextView)findViewById(R.id.t1); int c =s.indexOf("ap");//從頭開始找出第一個出現的ap //int c =s.lastIndexOf("ap");//從頭開始找出最後一個出現的ap s2=s.substring(c,c+5); t1.setText(""+s2); } } 展示 相關文章: [Android] Android 學習總集