簡單。生活。享受

●實作練習：xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 
    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="com.example.student.lab0201.basketball">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:padding="16dp">
        <TextView
            android:id="@+id/score"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="0"
            android:textSize="60dp"
            android:layout_gravity="center"/>
        <Button
            android:id="@+id/add3"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="+3 分球"
            android:textSize="20dp"
            android:layout_marginTop="16dp"
            android:layout_marginBottom="8dp"
            android:onClick="add3"/>
        <Button
            android:id="@+id/add2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="+2 分球"
            android:textSize="20dp"
            android:layout_marginTop="8dp"
            android:layout_marginBottom="8dp"
            android:onClick="add2"/>
        <Button
            android:id="@+id/add1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="罰球"
            android:textSize="20dp"
            android:layout_marginTop="8dp"
            android:layout_marginBottom="8dp"
            android:onClick="add1"/>

    </LinearLayout>
    <Button
        android:id="@+id/clear"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="重置"
        android:textSize="20dp"
        android:layout_marginBottom="16dp"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:onClick="clear"/>
</RelativeLayout>

●實作練習：java code

package com.example.student.lab0201;

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

public class basketball extends AppCompatActivity {
    TextView score;
    Button add3, add2, add1, clear;
    private int mPoint=0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_basketball);
        score = (TextView) findViewById(R.id.score);
        add3 = (Button) findViewById(R.id.add3);
        add2 = (Button) findViewById(R.id.add2);
        add1 = (Button) findViewById(R.id.add1);
        clear = (Button) findViewById(R.id.clear);
    }

    //add 3 points
    public void add3(View v) {
        mPoint+=3;
        String mP=String.valueOf(mPoint);
        score.setText(mP);
    }

    //add 2 points
    public void add2(View v) {
        mPoint+=2;
        String mP=String.valueOf(mPoint);
        score.setText(mP);
    }

    //freethrow add 1 point
    public void add1(View v) {
        mPoint+=1;
        String mP=String.valueOf(mPoint);
        score.setText(mP);
    }

    //clean
    public void clear(View v) {
        //要先讓分數歸0
        mPoint=0;
        score.setText("0");
    }

}

*程式參考(gitHub)：加減計算的練習與實作