[Android] Button 按鈕元件－Saioyan梟夜

Button button;

b1=(Button)findViewById(R.id.b1);

b1.setOnClickListener(new Button.OnClickListener(){

@Override public void onClick(View v) {

//這邊寫function

}

});

也可以先到XML檔案裏面設定Button的ID屬性和Click再到JAVA檔案裏面引用Button id

public void add(View v){

.........................

}

範例

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"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/b1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

JAVA

public class MainActivity extends AppCompatActivity  {
TextView text;
Button b1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
text = (TextView)findViewById(R.id.text);
b1=(Button)findViewById(R.id.b1);
b1.setOnClickListener(new Button.OnClickListener(){
    @Override
    public void onClick(View v) {
text.setText("123456789");
    }
});
    }
}