學習筆記專區

<resources>
    <string name="app_name">CF2</string>
    <string name="cel_lbl">攝氏：</string>
    <string name="fah_lbl">華氏：</string>
    <string name="btn_lbl">轉換成華式</string>
</resources>

<?xml version="1.0" encoding="utf-8"?>
<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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.iii.lcpan.cf2.MainActivity">

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:text="@string/cel_lbl" />

        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:inputType="numberDecimal"
            android:ems="10"
            android:id="@+id/celsius" />

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/btn_lbl"
            android:id="@+id/submit" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:text="@string/fah_lbl"
            android:id="@+id/fahrenheit" />

    </LinearLayout>
</RelativeLayout>

package com.iii.lcpan.cf2;

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

public class MainActivity extends AppCompatActivity implements View.OnClickListener{
    private EditText cel;
    private TextView fah;
    private Button btn;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);  
           setContentView(View view)
           Set the activity content to an explicit view.
        cel=(EditText) findViewById(R.id.celsius);
        fah=(TextView) findViewById(R.id.fahrenheit);
        btn=(Button) findViewById(R.id.submit);
            findViewById(int id)
            Finds a view that was identified by the id attribute from the XML that was processed in onCreate(Bundle).
        btn.setOnClickListener(this);
//this就是MainActivity物件
    }

    @Override
    public void onClick(View v) {
        double f=(Double.parseDouble(cel.getText().toString()))*9/5+32;
        fah.setText(getText(R.string.fah_lbl)+(Double.valueOf(f).toString()));
    }
}