【源码】Android简易计算器

这篇文章有些时日了，忘记了从哪里来了，不过确实是新手入门不错的参考

说明：每完成一次计算后，需先clear 清除记忆，当然也可以连算

 

XML布局

 

<?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" >    <TableLayout        android:id="@+id/tableLayout1"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:collapseColumns="4" >        <TableRow            android:id="@+id/tableRow_et"            android:layout_width="fill_parent"            android:layout_height="fill_parent" >            <EditText                android:id="@+id/et"                android:layout_width="fill_parent"                android:layout_height="fill_parent"                android:layout_span="4"                android:focusable="false"                 android:singleLine="true"                 android:inputType="text"                 android:gravity="right">            </EditText>        </TableRow>        <TableRow            android:id="@+id/tableRow1"            android:layout_width="fill_parent"            android:layout_height="fill_parent" >            <Button                android:id="@+id/bt_7"                android:layout_width="40px"                android:layout_height="40px"                android:text="7" />            <Button                android:id="@+id/bt_8"                android:layout_width="40px"                android:layout_height="40px"                android:text="8" />            <Button                android:id="@+id/bt_9"                android:layout_width="40px"                android:layout_height="40px"                android:text="9" />            <Button                android:id="@+id/bt_back"                android:layout_width="40px"                android:layout_height="40px"                android:text="back" />        </TableRow>        <TableRow            android:id="@+id/tableRow2"            android:layout_width="fill_parent"            android:layout_height="fill_parent" >            <Button                android:id="@+id/bt_4"                android:layout_width="40px"                android:layout_height="40px"                android:text="4" />            <Button                android:id="@+id/bt_5"                android:layout_width="40px"                android:layout_height="40px"                android:text="5" />            <Button                android:id="@+id/bt_6"                android:layout_width="40px"                android:layout_height="40px"                android:text="6" />            <Button                android:id="@+id/bt_divide"                android:layout_width="40px"                android:layout_height="40px"                android:text="/" />        </TableRow>        <TableRow            android:id="@+id/tableRow3"            android:layout_width="fill_parent"            android:layout_height="fill_parent" >            <Button                android:id="@+id/bt_1"                android:layout_width="40px"                android:layout_height="40px"                android:text="1" />            <Button                android:id="@+id/bt_2"                android:layout_width="40px"                android:layout_height="40px"                android:text="2" />            <Button                android:id="@+id/bt_3"                android:layout_width="40px"                android:layout_height="40px"                android:text="3" />            <Button                android:id="@+id/bt_multiply"                android:layout_width="40px"                android:layout_height="40px"                android:text="*" />        </TableRow>        <TableRow            android:id="@+id/tableRow4"            android:layout_width="fill_parent"            android:layout_height="fill_parent" >            <Button                android:id="@+id/bt_0"                android:layout_width="50px"                android:layout_height="40px"                android:text="0" />            <Button                android:id="@+id/bt_point"                android:layout_width="50px"                android:layout_height="40px"                android:text="." />            <Button                android:id="@+id/bt_add"                android:layout_width="50px"                android:layout_height="40px"                android:text="+" />            <Button                android:id="@+id/bt_sub"                android:layout_width="50px"                android:layout_height="40px"                android:text="-" />        </TableRow>        <TableRow            android:id="@+id/tableRow4"            android:layout_width="fill_parent"            android:layout_height="fill_parent" >            <Button                android:id="@+id/bt_equal"                android:layout_width="fill_parent"                android:layout_height="fill_parent"                android:layout_span="3"                android:text="=" />            <Button                android:id="@+id/bt_clear"                android:layout_width="50px"                android:layout_height="40px"                android:text="clear" />        </TableRow>    </TableLayout></LinearLayout>

源代码：

package android.sdk;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.Toast;public class Android_calculatorActivity extends Activity{private Button bt_1;private Button bt_2;private Button bt_3;private Button bt_4;private Button bt_5;private Button bt_6;private Button bt_7;private Button bt_8;private Button bt_9;private Button bt_0;private Button bt_add;private Button bt_sub; // 减private Button bt_multiply; // 乘private Button bt_divide; // 除private Button bt_back;private Button bt_equal; // 等于private Button bt_point; // 点private Button bt_clear; // 清除private EditText et_play; // 显示private String str_oper = "+"; // 运算符private StringBuffer str_display = new StringBuffer();; // 显示private String str_result; // 结果显示private double num1;private double num2;private boolean flag = true; // 小数点个数开关控制；private boolean b_sub, b_mul, b_div; // 运算符开关控制@Overridepublic void onCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.main);bt_0 = (Button) findViewById(R.id.bt_0);bt_1 = (Button) findViewById(R.id.bt_1);bt_2 = (Button) findViewById(R.id.bt_2);bt_3 = (Button) findViewById(R.id.bt_3);bt_4 = (Button) findViewById(R.id.bt_4);bt_5 = (Button) findViewById(R.id.bt_5);bt_6 = (Button) findViewById(R.id.bt_6);bt_7 = (Button) findViewById(R.id.bt_7);bt_8 = (Button) findViewById(R.id.bt_8);bt_9 = (Button) findViewById(R.id.bt_9);bt_add = (Button) findViewById(R.id.bt_add);bt_sub = (Button) findViewById(R.id.bt_sub);bt_multiply = (Button) findViewById(R.id.bt_multiply);bt_divide = (Button) findViewById(R.id.bt_divide);bt_back = (Button) findViewById(R.id.bt_back);bt_equal = (Button) findViewById(R.id.bt_equal);bt_point = (Button) findViewById(R.id.bt_point);bt_clear = (Button) findViewById(R.id.bt_clear);et_play = (EditText) findViewById(R.id.et);et_play.setText("0.0");bt_0.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){str_display.append("0");et_play.setText(str_display.toString());}});bt_1.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){str_display.append("1");et_play.setText(str_display.toString());}});bt_2.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){str_display.append("2");et_play.setText(str_display.toString());}});bt_3.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){str_display.append("3");et_play.setText(str_display.toString());}});bt_4.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){str_display.append("4");et_play.setText(str_display.toString());}});bt_5.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){str_display.append("5");et_play.setText(str_display.toString());}});bt_6.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){str_display.append("6");et_play.setText(str_display.toString());}});bt_7.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){str_display.append("7");et_play.setText(str_display.toString());}});bt_8.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){str_display.append("8");et_play.setText(str_display.toString());}});bt_9.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){str_display.append("9");et_play.setText(str_display.toString());}});bt_point.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){if (flag){str_display.append(".");flag = false;}}});bt_back.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){if (str_display.length() != 0){str_display.deleteCharAt(str_display.length() - 1);et_play.setText(str_display.toString());}}});bt_add.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){str_oper = "+";if (!(str_display.toString() == "")){num1 += Double.parseDouble(str_display.toString());str_display = new StringBuffer("");}if (!(str_result == null)){num1 = Double.parseDouble(str_result);str_result = null;}et_play.setText(String.valueOf(num1));flag = true;}});bt_sub.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){str_oper = "-";if (!b_sub && !(str_display.toString() == "")){num1 = Double.parseDouble(str_display.toString());et_play.setText(String.valueOf(num1));str_display = new StringBuffer("");b_sub = true;} else{if (!(str_display.toString() == "")){num1 -= Double.parseDouble(str_display.toString());str_display = new StringBuffer("");}if (!(str_result == null)){num1 = Double.parseDouble(str_result);str_result = null;}et_play.setText(String.valueOf(num1));}flag = true;}});bt_multiply.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){str_oper = "*";if (!b_mul && !(str_display.toString() == "")){num1 = Double.parseDouble(str_display.toString());et_play.setText(String.valueOf(num1));str_display = new StringBuffer("");b_mul = true;} else{if (!(str_display.toString() == "")){num1 *= Double.parseDouble(str_display.toString());str_display = new StringBuffer("");}if (!(str_result == null)){num1 = Double.parseDouble(str_result);str_result = null;}et_play.setText(String.valueOf(num1));}flag = true;}});bt_divide.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){str_oper = "/";if (!b_div && !(str_display.toString() == "")){num1 = Double.parseDouble(str_display.toString());et_play.setText(String.valueOf(num1));str_display = new StringBuffer("");b_div = true;} else{if (!(str_display.toString() == "")){if (Double.parseDouble(str_display.toString()) == 0){Toast.makeText(Android_calculatorActivity.this,"除数不能为0！", Toast.LENGTH_LONG).show();} else{num1 /= Double.parseDouble(str_display.toString());str_display = new StringBuffer("");}}if (!(str_result == null)){num1 = Double.parseDouble(str_result);str_result = null;}et_play.setText(String.valueOf(num1));}flag = true;}});bt_clear.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){str_oper = "+";str_display = new StringBuffer("");str_result = null;num1 = 0;num2 = 0;flag = true;b_sub = false;b_mul = false;b_div = false;et_play.setText("0.0");}});bt_equal.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v){if (str_oper.equals("+")){num2 = Double.parseDouble(str_display.toString());str_result = String.valueOf((num1 + num2));et_play.setText(str_result);str_display = new StringBuffer("");}if (str_oper.equals("-")){num2 = Double.parseDouble(str_display.toString());str_result = String.valueOf((num1 - num2));et_play.setText(str_result);str_display = new StringBuffer("");}if (str_oper.equals("*")){num2 = Double.parseDouble(str_display.toString());str_result = String.valueOf((num1 * num2));et_play.setText(str_result);str_display = new StringBuffer("");}if (str_oper.equals("/")){num2 = Double.parseDouble(str_display.toString());if (!(num2 == 0)){str_result = String.valueOf((num1 / num2));et_play.setText(str_result);} else{Toast.makeText(Android_calculatorActivity.this,"除数不能为0！", Toast.LENGTH_LONG).show();}str_display = new StringBuffer("");}}});}