說明:簡易計算機,當輸入為空白時,彈出對話方塊提示:沒有輸入數字;當被除數為0時,彈出對話方塊提示:被除數不可為空;輸入數字後,點擊加減乘除按鈕,可以進行相應運算;點擊menu菜單後,螢幕最下方出現關於和退出按鈕,點擊關於,彈出關於對話方塊顯示相應資訊;點擊退出,直接退出程式。
1.布局,activity_main.xml代碼:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="center_vertical" android:orientation="vertical" > <RelativeLayout android:id="@+id/relative1" android:layout_width="wrap_content" android:layout_height="wrap_content" ><!-- 參與運算的第一個數 --> <EditText android:id="@+id/num1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_marginTop="10dp" android:ems="4" android:inputType="number" > <requestFocus /> </EditText><!--運算子號 --> <TextView android:id="@+id/fuhao" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="15dp" android:layout_toRightOf="@id/num1" android:padding="@dimen/padding_medium" android:text="@string/fuhao" /><!-- 參與運算的第二個數 --> <EditText android:id="@+id/num2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:layout_toRightOf="@id/fuhao" android:ems="4" android:inputType="number" /><!-- 等號 --> <TextView android:id="@+id/denghao" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="15dp" android:layout_toRightOf="@id/num2" android:padding="@dimen/padding_medium" android:text="@string/denghao" /><!-- 結果 --> <TextView android:id="@+id/result" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="15dp" android:layout_toRightOf="@id/denghao" android:padding="@dimen/padding_medium" android:text="@string/result" /> </RelativeLayout> <RelativeLayout android:layout_width="wrap_content" android:layout_height="wrap_content" ><!-- 加號 --> <Button android:id="@+id/add" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_centerHorizontal="true" android:ems="4" android:text="@string/add" /><!-- 減號 --> <Button android:id="@+id/sub" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:layout_toRightOf="@id/add" android:ems="4" android:text="@string/sub" /><!-- 乘號 --> <Button android:id="@+id/mult" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:layout_toRightOf="@id/sub" android:ems="4" android:text="@string/mult" /><!-- 除號 --> <Button android:id="@+id/divid" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_toRightOf="@id/mult" android:ems="4" android:text="@string/divid" /> </RelativeLayout> <RelativeLayout android:layout_width="wrap_content" android:layout_height="wrap_content" ><!-- 關於按鈕 --> <Button android:id="@+id/about" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/about" /><!-- 退出按鈕 --> <Button android:id="@+id/quit" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/quit" /> </RelativeLayout></LinearLayout>
2.MainActivity.java代碼:
package cn.bzu.case1;import java.text.DecimalFormat;import cn.bzu.model.CalculatorBiz;import android.os.Bundle;import android.app.Activity;import android.app.AlertDialog;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import android.widget.TextView;import android.widget.Toast;import android.widget.RemoteViews.ActionException;import android.support.v4.app.NavUtils;public class MainActivity extends Activity {private Double number1, number2;private EditText num1, num2;private TextView result, fuhao;private Button add, sub, mult, divid, quit, about;CalculatorBiz calculator;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);num1 = (EditText) this.findViewById(R.id.num1);num2 = (EditText) this.findViewById(R.id.num2);add = (Button) this.findViewById(R.id.add);sub = (Button) this.findViewById(R.id.sub);mult = (Button) this.findViewById(R.id.mult);divid = (Button) this.findViewById(R.id.divid);fuhao = (TextView) this.findViewById(R.id.fuhao);result = (TextView) this.findViewById(R.id.result);quit = (Button) this.findViewById(R.id.quit);about = (Button) this.findViewById(R.id.about);quit.setVisibility(View.INVISIBLE);about.setVisibility(View.INVISIBLE);add.setOnClickListener(new CalculatorClickListener());sub.setOnClickListener(new CalculatorClickListener());mult.setOnClickListener(new CalculatorClickListener());divid.setOnClickListener(new CalculatorClickListener());}private class CalculatorClickListener implements OnClickListener {@Overridepublic void onClick(View v) {// 如果editText為空白if (num1.getText().toString().equalsIgnoreCase("")) {Toast.makeText(MainActivity.this, "沒有輸入數字!", Toast.LENGTH_SHORT).show();} else if (num2.getText().toString().equalsIgnoreCase("")) {Toast.makeText(MainActivity.this, "沒有輸入數字!", Toast.LENGTH_SHORT).show();} else {number1 = Double.parseDouble(num1.getText().toString());number2 = Double.parseDouble(num2.getText().toString());if (v.equals(add)) {result.setText(number1 + number2 + "");fuhao.setText("+");}if (v.equals(sub)) {result.setText(number1 - number2 + "");fuhao.setText("-");}if (v.equals(mult)) {result.setText(number1 * number2 + "");fuhao.setText("*");}if (v.equals(divid)) {if (number2 == 0) {Toast.makeText(MainActivity.this, "被除數不能為零!",Toast.LENGTH_SHORT).show();} else {result.setText(number1 / number2 + "");fuhao.setText("/");}}}}}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {super.onCreateOptionsMenu(menu);// 建立菜單,並設定表徵圖,使用系統提供的表徵圖,menu.add(0, R.id.about, 0, "關於").setIcon(android.R.drawable.ic_dialog_info);menu.add(0, R.id.quit, 1, "退出").setIcon(android.R.drawable.ic_lock_power_off);menu.findItem(R.id.quit);// 返回true即顯示菜單return true;}@Override// 響應菜單單擊事件,public boolean onOptionsItemSelected(MenuItem item) {switch (item.getItemId()) {case R.id.about:// 關於AlertDialog.Builder dialog = new AlertDialog.Builder(this);dialog.setTitle("關於");dialog.setMessage("簡易計算機!\n作者:vivy\n版本:1.0");dialog.show();break;case R.id.quit:// 退出this.finish();break;}return super.onOptionsItemSelected(item);}}
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