Zi 字媒體
2017-07-25T20:27:27+00:00
Random x = new Random();
示範
XML
xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<TextView
android:id="@+id/t1"
android:layout_width="wrap_content"
android:layout_height="16dp"
android:text="將抽出1~49號"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/b1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="random"
android:text="隨機選號"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent" />
android.support.constraint.ConstraintLayout>
JAVA
public class MainActivity extends AppCompatActivity {
TextView t1;
int a=0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
t1=(TextView)findViewById(R.id.t1);
}
public void random(View v){
Random x = new Random();
a=x.nextInt(49);
t1.setText(String.valueOf(a));
}
}
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[Android] Android 學習總集
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