Android——本息计算器

使用的是2.3.3版本。

一、效果图

二、main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <!-- 程序标题 -->
    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/txt_money"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <!-- 存款本金文本框 -->
    <EditText
        android:id="@+id/txtMoney" 
        android:hint="@string/hint_money"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="number" >

        <requestFocus />
    </EditText>

    <!-- 存款年限 -->
    <TextView
        android:id="@+id/TextView01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/txt_year"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <!-- 存款年限文本框 -->
    <EditText
        android:id="@+id/txtYear"
        android:hint="@string/hint_year"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="number" />

    <!-- 计算按钮 -->
    <Button
        android:id="@+id/btnCalc"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/btn_calc" />

    <!-- 清除按钮 -->
    <Button
        android:id="@+id/btnClear"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/btn_clear" />

    <!-- 本金总额和利息显示文本 -->
    <TextView
        android:id="@+id/txtResult"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge" />

</LinearLayout>

三、strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="hello">Hello World, BankActivity!</string>
    <string name="app_name">本息计算器</string>
    <string name="txt_money">存款本金</string>
    <string name="txt_year">存款年限</string>
    <string name="btn_calc">计算</string>
    <string name="btn_clear">清除</string>
    <string name="view_result"></string>
    <string name="hint_money">请输入本金</string>
    <string name="hint_year">请输入年份</string>

</resources>

四、AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="org.e276.bank"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="10" />

    <application
        android:icon="@drawable/girl_icon"
        android:label="@string/app_name" >
        <activity
            android:name=".BankActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

五、BankActivity.java

package org.e276.bank;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

/**
 * 本息计算器
 * 
 * @author miao
 * 
 */
public class BankActivity extends Activity {

	private EditText txtMoney;// 存款金额文本框
	private EditText txtYear;// 存款年限文本框

	private Button btnCalc;// 计算按钮
	private Button btnClear;// 清除按钮

	private TextView txtResult;// 显示结果，本息总额

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		// 得到所有的控件对象
		txtMoney = (EditText) super.findViewById(R.id.txtMoney);
		txtYear = (EditText) super.findViewById(R.id.txtYear);
		btnCalc = (Button) super.findViewById(R.id.btnCalc);
		btnClear = (Button) super.findViewById(R.id.btnClear);
		txtResult = (TextView) super.findViewById(R.id.txtResult);
		
		// 计算按钮
		btnCalc.setOnClickListener(calc);
		// 清除按钮
		btnClear.setOnClickListener(reset);

	}

	/**
	 * 计算按钮
	 */
	private OnClickListener calc = new OnClickListener() {

		public void onClick(View v) {
			// 存款本金
			double money = Double.parseDouble(txtMoney.getText().toString());
			// 存款年限
			double year = Double.parseDouble(txtYear.getText().toString());
			// 本息总额
			double result = 0;
			// 利息率
			double rate = 0;
			// 根据存款年限判断利息率
			if (year == 1) {
				rate = 0.025;
			} else if (year == 2) {
				rate = 0.027;
			} else if (year >= 3 && year < 5) {
				rate = 0.0324;
			} else if (year >= 5) {
				rate = 0.036;
			}
			// 计算利息
			double interest = money * rate;
			result = money + interest * year;
			
			/*
			 * 调用资源文件里的信息，方便国际化。
			 * super.getResources().getString(R.string.hello);
			 * 如果在内部类里调用，BankActivity.this.getResources().getString(R.string.hello);
			 */
			
			// 显示本息总额
			txtResult.setText("本息总额是：" + String.valueOf(result) + " RMB"
					+ "\n其中利息是：" + (interest * year) + " RMB");
		}
	};

	/**
	 * 清除按钮
	 */
	private OnClickListener reset = new OnClickListener() {

		public void onClick(View v) {
			txtMoney.setText("");
			txtYear.setText("");
			txtResult.setText("");
		}
	};

}

六、demo

Android-Bank.zip