1创建工程
注意这个名称的命名：
3. UC结构及相关代码
UC.java 用于执行单位换算的Activity
// UC.java
package com.apress.uc;
import android.app.Activity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
public class UC extends Activity
{
private int position = 0;
private double[] multipliers =
{
0.0015625, // Acres to square miles
101325.0, // Atmospheres to Pascals
100000.0, // Bars to Pascals
0, // Degrees Celsius to Degrees Fahrenheit (placeholder)
0, // Degrees Fahrenheit to Degrees Celsius (placeholder)
0.00001, // Dynes to Newtons
0.3048, // Feet/Second to Metres/Second
0.0284130625, // Fluid Ounces (UK) to Litres
0.0295735295625, // Fluid Ounces (US) to Litres
746.0, // Horsepower (electric) to Watts
735.499, // Horsepower (metric) to Watts
1/1016.0469088, // Kilograms to Tons (UK or long)
1/907.18474, // Kilograms to Tons (US or short)
1/0.0284130625, // Litres to Fluid Ounces (UK)
1/0.0295735295625, // Litres to Fluid Ounces (US)
331.5, // Mach Number to Metres/Second
1/0.3048, // Metres/Second to Feet/Second
1/331.5, // Metres/Second to Mach Number
0.833, // Miles/Gallon (UK) to Miles/Gallon (US)
1/0.833, // Miles/Gallon (US) to Miles/Gallon (UK)
100000.0, // Newtons to Dynes
1/101325.0, // Pascals to Atmospheres
0.00001, // Pascals to Bars
640.0, // Square Miles to Acres
1016.0469088, // Tons (UK or long) to Kilograms
907.18474, // Tons (US or short) to Kilograms
1/746.0, // Watts to Horsepower (electic)
1/735.499 // Watts to Horsepower (metric)
};
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final EditText etUnits = (EditText) findViewById(R.id.units);
final Spinner spnConversions = (Spinner) findViewById(R.id.conversions);
ArrayAdapter<CharSequence> aa;
aa = ArrayAdapter.
createFromResource(this, R.array.conversions,
android.R.layout.simple_spinner_item);
aa.setDropDownViewResource(android.R.layout.simple_spinner_item);
spnConversions.setAdapter(aa);
AdapterView.OnItemSelectedListener oisl;
oisl = new AdapterView.OnItemSelectedListener()
{
@Override
public void onItemSelected(AdapterView<?> parent, View view,
int position, long id)
{
UC.this.position = position;
}
@Override
public void onNothingSelected(AdapterView<?> parent)
{
System.out.println("nothing");
}
};
spnConversions.setOnItemSelectedListener(oisl);
final Button btnClear = (Button) findViewById(R.id.clear);
AdapterView.OnClickListener ocl;
ocl = new AdapterView.OnClickListener()
{
@Override
public void onClick(View v)
{
etUnits.setText("");
}
};
btnClear.setOnClickListener(ocl);
btnClear.setEnabled(false);
final Button btnConvert = (Button) findViewById(R.id.convert);
ocl = new AdapterView.OnClickListener()
{
@Override
public void onClick(View v)
{
String text = etUnits.getText().toString();
double input = Double.parseDouble(text);
double result = 0;
if (position == 3)
result = input*9.0/5.0+32; // Celsius to Fahrenheit
else
if (position == 4)
result = (input-32)*5.0/9.0; // Fahrenheit to Celsius
else
result = input*multipliers[position];
etUnits.setText(""+result);
}
};
btnConvert.setOnClickListener(ocl);
btnConvert.setEnabled(false);
Button btnClose = (Button) findViewById(R.id.close);
ocl = new AdapterView.OnClickListener()
{
@Override
public void onClick(View v)
{
finish();
}
};
btnClose.setOnClickListener(ocl);
TextWatcher tw;
tw = new TextWatcher()
{
@Override
public void afterTextChanged(Editable s)
{
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after)
{
}
@Override
public void onTextChanged(CharSequence s, int start, int before,
int count)
{
if (etUnits.getText().length() == 0)
{
btnClear.setEnabled(false);
btnConvert.setEnabled(false);
}
else
{
btnClear.setEnabled(true);
btnConvert.setEnabled(true);
}
}
};
etUnits.addTextChangedListener(tw);
}
}
main.xml 用于保存小部件和布局信息的main.xml文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center_vertical"
android:background="@drawable/gradientbg"
android:padding="5dip">
<LinearLayout android:layout_width="fill_parent"
android:layout_height="wrap_content">
<TextView android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginRight="10dip"
android:text="@string/units"
android:textColor="#000000"
android:textSize="15sp"
android:textStyle="bold"/>
<EditText android:id="@+id/units"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:hint="type a number"
android:inputType="numberDecimal|numberSigned"
android:maxLines="1"/>
</LinearLayout>
<Spinner android:id="@+id/conversions"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:prompt="@string/prompt"/>
<LinearLayout android:layout_width="fill_parent"
android:layout_height="wrap_content">
<Button android:id="@+id/clear"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="@string/clear"/>
<Button android:id="@+id/convert"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="@string/convert"/>
<Button android:id="@+id/close"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="@string/close"/>
</LinearLayout>
</LinearLayout>
strings.xml 保存了应用中的字符串
<?xml version="1.0" encoding="utf-8"?> <resources> <string name="app_name">Units Converter</string> <string name="clear">Clear</string> <string name="close">Close</string> <string name="convert">Convert</string> <string name="prompt">Select a conversion</string> <string name="units">Units</string> </resources>
arrays.xml 文件中保存了换算类型的字符串数组
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string-array name="conversions">
<item>Acres to Square Miles</item>
<item>Atmospheres to Pascals</item>
<item>Bars to Pascals</item>
<item>Degrees Celsius to Degrees Fahrenheit</item>
<item>Degrees Fahrenheit to Degrees Celsius</item>
<item>Dynes to Newtons</item>
<item>Feet/Second to Metres/Second</item>
<item>Fluid Ounces (UK) to Litres</item>
<item>Fluid Ounces (US) to Litres</item>
<item>Horsepower (electric) to Watts</item>
<item>Horsepower (metric) to Watts</item>
<item>Kilograms to Tons (UK or long)</item>
<item>Kilograms to Tons (US or short)</item>
<item>Litres to Fluid ounces (UK)</item>
<item>Litres to Fluid ounces (US)</item>
<item>Mach Number to Metres/Second</item>
<item>Metres/Second to Feet/Second</item>
<item>Metres/Second to Mach Number</item>
<item>Miles/Gallon (UK) to Miles/Gallon (US)</item>
<item>Miles/Gallon (US) to Miles/Gallon (UK)</item>
<item>Newtons to Dynes</item>
<item>Pascals to Atmospheres</item>
<item>Pascals to Bars</item>
<item>Square Miles to Acres</item>
<item>Tons (UK or long) to Kilograms</item>
<item>Tons (US or short) to Kilograms</item>
<item>Watts to Horsepower (electric)</item>
<item>Watts to Horsepower (metric)</item>
</string-array>
</resources>
gradientbg.xml 文件保存了用于Activity背景色的渐变形状
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<gradient android:startColor="#fccb06"
android:endColor="#fd6006"
android:angle="270"/>
<corners android:radius="10dp"/>
</shape>
4 虚拟机运行结果
注意：
其中的uc.xml 换成以下代码可以运行
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
tools:context="com.apress.uc.UC" >
</menu>
时间： 2024-10-28 02:36:16