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

<RelativeLayoutxmlns: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"><EditTextandroid:id="@+id/num1"android:layout_width="80dp"android:layout_height="wrap_content"android:inputType="number"/><TextViewandroid:id="@+id/type"android:layout_width="40dp"android:layout_height="50dp"android:layout_toRightOf="@id/num1"android:gravity="center"/><EditTextandroid:id="@+id/num2"android:layout_width="80dp"android:layout_height="wrap_content"android:layout_toRightOf="@id/num1"android:layout_marginLeft="50dp"android:inputType="number"/><TextViewandroid:id="@+id/equal"android:layout_width="80dp"android:layout_height="50dp"android:layout_toRightOf="@id/num2"android:gravity="center"/><Buttonandroid:id="@+id/add"android:layout_width="70dp"android:layout_height="wrap_content"android:layout_below="@id/num1"android:text="@string/add"/><Buttonandroid: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"/><Buttonandroid: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"/><Buttonandroid:id="@+id/p"android:layout_width="70dp"android:layout_height="wrap_content"android:layout_toRightOf="@id/mul"android:layout_alignTop="@id/mul"android:text="@string/p"/></RelativeLayout>

二、计算器实现的方法

publicclassCalculatorBiz{publicfloatadd(floatnum1,floatnum2){returnnum1+num2;}publicfloatsub(floatnum1,floatnum2){returnnum1-num2;}publicfloatmul(floatnum1,floatnum2){returnnum1*num2;}publicfloatp(floatnum1,floatnum2){returnnum1/num2;}}

三、MainActivity主要方法

publicclassMainActivityextendsActivity{//定义组件privateEditTextinputnum1;privateEditTextinputnum2;privateTextViewtype;privateTextViewequal;privateButtonadd;privateButtonsub;privateButtonmul;privateButtonp;CalculatorBizcalculator=newCalculatorBiz();@OverridepublicvoidonCreate(BundlesavedInstanceState){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);p=(Button)findViewById(R.id.p);type.setTextColor(Color.WHITE);equal.setTextColor(Color.WHITE);add.setOnClickListener(newOnClickListener(){@OverridepublicvoidonClick(Viewv){Stringnum1=inputnum1.getText().toString();Stringnum2=inputnum2.getText().toString();floata=Float.parseFloat(num1);floatb=Float.parseFloat(num2);type.setText("+");equal.setText("="+calculator.add(a,b));}});sub.setOnClickListener(newOnClickListener(){@OverridepublicvoidonClick(Viewv){Stringnum1=inputnum1.getText().toString();Stringnum2=inputnum2.getText().toString();floata=Float.parseFloat(num1);floatb=Float.parseFloat(num2);type.setText("-");equal.setText("="+calculator.sub(a,b));}});mul.setOnClickListener(newOnClickListener(){@OverridepublicvoidonClick(Viewv){Stringnum1=inputnum1.getText().toString();Stringnum2=inputnum2.getText().toString();floata=Float.parseFloat(num1);floatb=Float.parseFloat(num2);type.setText("*");equal.setText("="+calculator.mul(a,b));}});p.setOnClickListener(newOnClickListener(){@OverridepublicvoidonClick(Viewv){Stringnum1=inputnum1.getText().toString();Stringnum2=inputnum2.getText().toString();floata=Float.parseFloat(num1);floatb=Float.parseFloat(num2);type.setText("/");equal.setText("="+calculator.p(a,b));}});}@OverridepublicbooleanonCreateOptionsMenu(Menumenu){super.onCreateOptionsMenu(menu);menu.add(0,1,0,"关于");menu.add(0,2,1,"退出");menu.findItem(2);returntrue;}publicbooleanonOptionsItemSelected(MenuItemitem){if(item.getItemId()==1){Toast.makeText(this,"详细内容\n"+"作者:dyp\n"+"版本:version1",Toast.LENGTH_LONG).show();}elseif(item.getItemId()==2){Toast.makeText(this,"退出\n"+"你确定退出程序?",Toast.LENGTH_LONG).show();}returnsuper.onOptionsItemSelected(item);}}