android实现简易计算器

本文实例为大家分享了android实现简易计算器展示的具体代码，供大家参考，具体内容如下

效果图：

一、如图，首先布局计算器主页显示

activity_main.xml

<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" >

<EditText
 android:id="@+id/num1"
 android:layout_width="80dp"
 android:layout_height="wrap_content"
 android:inputType="number" />

<TextView
 android:id="@+id/type"
 android:layout_width="40dp"
 android:layout_height="50dp"
 android:layout_toRightOf="@id/num1"
 android:gravity="center" />

<EditText
 android:id="@+id/num2"
 android:layout_width="80dp"
 android:layout_height="wrap_content"
 android:layout_toRightOf="@id/num1"
 android:layout_marginLeft="50dp"
 android:inputType="number" />

<TextView
 android:id="@+id/equal"
 android:layout_width="80dp"
 android:layout_height="50dp"
 android:layout_toRightOf="@id/num2"
 android:gravity="center" />

<Button
 android:id="@+id/add"
 android:layout_width="70dp"
 android:layout_height="wrap_content"
 android:layout_below="@id/num1"
 android:text="@string/add" />

<Button
 android:id="@+id/sub"
 android:layout_width="70dp"
 android:layout_height="wrap_content"
 android:layout_toRightOf="@id/add"
 android:layout_alignTop="@id/add"
 android:text="@string/sub" />

<Button
 android:id="@+id/mul"
 android:layout_width="70dp"
 android:layout_height="wrap_content"
 android:layout_toRightOf="@id/sub"
 android:layout_alignTop="@id/sub"
 android:text="@string/mul" />

<Button
 android:id="@+id/div"
 android:layout_width="70dp"
 android:layout_height="wrap_content"
 android:layout_toRightOf="@id/mul"
 android:layout_alignTop="@id/mul"
 android:text="@string/div" />
</RelativeLayout>

二、计算器实现的方法

public class CalculatorBiz {

public float add(float num1,float num2){
return num1+num2;
}

public float sub(float num1,float num2){
return num1-num2;
}

public float mul(float num1,float num2){
return num1*num2;
}

public float div(float num1,float num2){
return num1/num2;
}

}

三、MainActivity主要方法

public class MainActivity extends Activity {
//定义组件
private EditText inputnum1;
private EditText inputnum2;
private TextView type;
private TextView equal;
private Button add;
private Button sub;
private Button mul;
private Button div;
CalculatorBiz calculator=new CalculatorBiz();

@Override
public void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 //查找组件
 inputnum1=(EditText) findViewById(R.id.num1);
 inputnum2=(EditText) findViewById(R.id.num2);
 type=(TextView) findViewById(R.id.type);
 equal=(TextView) findViewById(R.id.equal);
 add=(Button) findViewById(R.id.add);
 sub=(Button) findViewById(R.id.sub);
 mul=(Button) findViewById(R.id.mul);
 div=(Button) findViewById(R.id.div);

type.setTextColor(Color.WHITE);
 equal.setTextColor(Color.WHITE);

add.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
String num1=inputnum1.getText().toString();
String num2=inputnum2.getText().toString();
float a=Float.parseFloat(num1);
float b=Float.parseFloat(num2);
type.setText("+");
equal.setText("="+calculator.add(a, b));

}});
 sub.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
String num1=inputnum1.getText().toString();
String num2=inputnum2.getText().toString();
float a=Float.parseFloat(num1);
float b=Float.parseFloat(num2);
type.setText("-");
equal.setText("="+calculator.sub(a, b));

}});
 mul.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
String num1=inputnum1.getText().toString();
String num2=inputnum2.getText().toString();
float a=Float.parseFloat(num1);
float b=Float.parseFloat(num2);
type.setText("*");
equal.setText("="+calculator.mul(a, b));

}});
 div.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
String num1=inputnum1.getText().toString();
String num2=inputnum2.getText().toString();
float a=Float.parseFloat(num1);
float b=Float.parseFloat(num2);
type.setText("/");
equal.setText("="+calculator.div(a, b));

}});

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
 super.onCreateOptionsMenu(menu);
 menu.add(0, 1, 0, "关于");
 menu.add(0, 2, 1, "退出");
 menu.findItem(2);
 return true;
}
public boolean onOptionsItemSelected(MenuItem item){
 if(item.getItemId() == 1){  
 Toast.makeText(this, "详细内容\n"+"作者：dyp\n"+"版本：version1", Toast.LENGTH_LONG).show();  
 }else if(item.getItemId() == 2){  
 Toast.makeText(this, "退出\n"+"你确定退出程序？", Toast.LENGTH_LONG).show();  
 }  
 return super.onOptionsItemSelected(item);
}

}

来源：https://blog.csdn.net/duyuping/article/details/7989530