Java: 期末作業2

參考文獻 :
http://www.sdk.tw/2014/12/android-sdk-android-studio.html

http://chiachiku.pixnet.net/blog/post/64235911-android%E7%A8%8B%E5%BC%8F%E7%AF%84%E4%BE%8B%EF%BC%88%E4%B8%80%EF%BC%89bmi%E8%A8%88%E7%AE%97%E7%A8%8B%E5%BC%8F---%E8%A4%87%E8%A3%BD%E7%AF%87

題目: BMI

安裝 Android Studio : https://developer.android.com/sdk/index.html

步驟 :
（一）建立新專案

（二）Application name裡的「example」可改成名字（或程式的名字），在此使用「BMI」為Application name，點選next直到finish。。

（三）點選values裡的strings.xml，將以下此段程式碼貼上。

<resources>
<string name="app_name">BMI</string>
<string name="menu_settings">Settings</string>
<string name="title_activity_bmi">BMI</string>
<string name="bmi_height">身高 (cm)</string>
<string name="bmi_weight">體重 (kg)</string>
<string name="bmi_calculate">計算 BMI 值</string>
<string name="hello_world"></string>
</resources>

（四）在values底下創立一個名為advice的「Values resource file」。

（五）將以下程式碼貼上剛剛創好的advice裡。

<?xml version="1.0" encoding="UTF-8"?>

<resources>

<string name="advice_light">你該多吃點</string>
<string name="advice_average">體型很棒喔</string>
<string name="advice_heavy">你該節食了</string>

</resources>

（六）接著，將以下程式碼貼在「layout」裡的「activity_main.xml」裡，點進activity_main.xml後選擇下方的text

<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" >

<TextView

android:id="@+id/textHeight"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/bmi_height" />

<EditText

android:id="@+id/inputHeight"
style="editTextStyle"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/textHeight"
android:inputType="number" />

<TextView

android:id="@+id/textWeight"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/inputHeight"
android:text="@string/bmi_weight" />

<EditText

android:id="@+id/inputWeight"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/textWeight"
android:ems="10"
android:inputType="number" />

<Button

android:id="@+id/buttonCalculate"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/inputWeight"
android:text="@string/bmi_calculate" />

<TextView

android:id="@+id/textResult"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/buttonCalculate" />

<TextView

android:id="@+id/textSuggest"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/textResult" />

</RelativeLayout>

（七）再來進到java裡的MainActivity(若名稱有更改會不一樣)，貼上以下程式碼。

package com.practice.bmi;
import java.text.DecimalFormat;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class BMI extends Activity {

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_bmi);

//Listen for button clicks

Button button = (Button)findViewById(R.id.buttonCalculate);

button.setOnClickListener(calcBMI);

}

@Override

public boolean onCreateOptionsMenu(Menu menu) {

getMenuInflater().inflate(R.menu.activity_bmi, menu);

return true;

}

private OnClickListener calcBMI = new OnClickListener()

{

public void onClick(View v)

{

DecimalFormat nf = new DecimalFormat("0.00");

EditText fieldheight = (EditText)findViewById(R.id.inputHeight);

EditText fieldweight = (EditText)findViewById(R.id.inputWeight);

double height = Double.parseDouble(fieldheight.getText().toString())/100;

double weight = Double.parseDouble(fieldweight.getText().toString());

double BMI = weight / (height * height);

TextView result = (TextView)findViewById(R.id.textResult);

result.setText("Your BMI is " + nf.format(BMI));

//Give health advice

TextView fieldsuggest = (TextView)findViewById(R.id.textSuggest);

if(BMI>25){

fieldsuggest.setText(R.string.advice_heavy);

}else if(BMI<20){

fieldsuggest.setText(R.string.advice_light);

}else {

fieldsuggest.setText(R.string.advice_average);

}

}

};

}

目前樣式