设计一个简单的计算器。
第一个Activity的界面。
第二个Activity显示算式和计算结果。
第一个Activity代码：
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button; public class MainActivity extends Activity { Button one,two,three,four,five,six,seven,eight,nine,zero,div,mod,mul,fenshu,sub,equal,point,add;
double num1,num2,num,xiaoshudian;
int flag,ispoint;
char operation[]=new char[2];
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
num1=0;num2=0;num=0;flag=0;ispoint=0;xiaoshudian=0.1;
one=(Button)findViewById(R.id.one);
two=(Button)findViewById(R.id.two);
three=(Button)findViewById(R.id.three);
four=(Button)findViewById(R.id.four);
five=(Button)findViewById(R.id.five);
six=(Button)findViewById(R.id.six);
seven=(Button)findViewById(R.id.seven);
eight=(Button)findViewById(R.id.eight);
nine=(Button)findViewById(R.id.nine);
zero=(Button)findViewById(R.id.zero);
div=(Button)findViewById(R.id.div);
mod=(Button)findViewById(R.id.mod);
mul=(Button)findViewById(R.id.mul);
fenshu=(Button)findViewById(R.id.fenshu);
sub=(Button)findViewById(R.id.sub);
add=(Button)findViewById(R.id.add);
equal=(Button)findViewById(R.id.equal);
point=(Button)findViewById(R.id.point);
one.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
if(flag==0){
if(ispoint==0)num1=num1*10+1;
else {num1=num1+1*xiaoshudian;xiaoshudian/=10;}
}
else{
if(ispoint==0)num2=num2*10+1;
else{num2=num2+1*xiaoshudian;xiaoshudian/=10;}
}
}
});
two.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
if(flag==0){
if(ispoint==0)num1=num1*10+2;
else {num1=num1+2*xiaoshudian;xiaoshudian/=10;}
}
else{
if(ispoint==0)num2=num2*10+2;
else{num2=num2+2*xiaoshudian;xiaoshudian/=10;}
}
}
});
three.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
if(flag==0){
if(ispoint==0)num1=num1*10+3;
else {num1=num1+3*xiaoshudian;xiaoshudian/=10;}
}
else{
if(ispoint==0)num2=num2*10+3;
else{num2=num2+3*xiaoshudian;xiaoshudian/=10;}
}
}
});
four.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
if(flag==0){
if(ispoint==0)num1=num1*10+4;
else {num1=num1+4*xiaoshudian;xiaoshudian/=10;}
}
else{
if(ispoint==0)num2=num2*10+4;
else{num2=num2+4*xiaoshudian;xiaoshudian/=10;}
}
}
});
five.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
if(flag==0){
if(ispoint==0)num1=num1*10+5;
else {num1=num1+5*xiaoshudian;xiaoshudian/=10;}
}
else{
if(ispoint==0)num2=num2*10+5;
else{num2=num2+5*xiaoshudian;xiaoshudian/=10;}
}
}
});
six.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
if(flag==0){
if(ispoint==0)num1=num1*10+6;
else {num1=num1+6*xiaoshudian;xiaoshudian/=10;}
}
else{
if(ispoint==0)num2=num2*10+6;
else{num2=num2+6*xiaoshudian;xiaoshudian/=10;}
}
}
});
seven.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
if(flag==0){
if(ispoint==0)num1=num1*10+7;
else {num1=num1+7*xiaoshudian;xiaoshudian/=10;}
}
else{
if(ispoint==0)num2=num2*10+7;
else{num2=num2+7*xiaoshudian;xiaoshudian/=10;}
}
}
});
eight.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
if(flag==0){
if(ispoint==0)num1=num1*10+8;
else {num1=num1+8*xiaoshudian;xiaoshudian/=10;}
}
else{
if(ispoint==0)num2=num2*10+8;
else{num2=num2+8*xiaoshudian;xiaoshudian/=10;}
}
}
});
nine.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
if(flag==0){
if(ispoint==0)num1=num1*10+9;
else {num1=num1+9*xiaoshudian;xiaoshudian/=10;}
}
else{
if(ispoint==0)num2=num2*10+9;
else{num2=num2+9*xiaoshudian;xiaoshudian/=10;}
}
}
});
zero.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
if(flag==0){
if(ispoint==0)num1=num1*10;
else {xiaoshudian/=10;}
}
else{
if(ispoint==0)num2=num2*10;
else{xiaoshudian/=10;}
}
}
});
point.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
ispoint=1;
}
});
add.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
flag=1;
ispoint=0;
}
});
sub.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
flag=2;
ispoint=0;
}
});
mul.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
flag=3;
ispoint=0;
}
});
div.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
flag=4;
ispoint=0;
}
});
equal.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
if(flag==1){num=num1+num2;operation[0]='+';}
else if(flag==2){num=num1-num2;operation[0]='-';}
else if(flag==3){num=num1*num2;operation[0]='*';}
else if(flag==4){num=num1/num2;operation[0]='/';}
Intent intent=new Intent(MainActivity.this,SecondActivity.class);
intent.putExtra("num1", new Double(num1).toString());
intent.putExtra("opreation",new String(operation).toString());
intent.putExtra("num2", new Double(num2).toString());
intent.putExtra("num", new Double(num).toString());
startActivity(intent);
}
});
} @Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
} }
第二个Activity代码：
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText; public class SecondActivity extends Activity{
EditText text;
Button myButton;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.second);
text=(EditText)findViewById(R.id.edt);
myButton=(Button)findViewById(R.id.btn);
Intent intent=getIntent();
String num1=intent.getStringExtra("num1");
String operation=intent.getStringExtra("opreation");
String num2=intent.getStringExtra("num2");
String num=intent.getStringExtra("num");
text.setText(num1+operation+num2+"="+num);
myButton.setOnClickListener(new myButtonListener());
}
class myButtonListener implements OnClickListener{
public void onClick(View arg0){
Intent intent=new Intent(SecondActivity.this,MainActivity.class);
startActivity(intent);
}
}
}
第一个Activity布局：
<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"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<Button
android:id="@+id/seven"
android:layout_width="40px"
android:layout_height="wrap_content"
android:text="7"
/>
<Button
android:id="@+id/eight"
android:layout_toRightOf="@id/seven"
android:layout_width="40px"
android:layout_height="wrap_content"
android:text="8"
/>
<Button
android:id="@+id/nine"
android:layout_toRightOf="@id/eight"
android:layout_width="40px"
android:layout_height="wrap_content"
android:text="9"
/>
<Button
android:id="@+id/div"
android:layout_toRightOf="@id/nine"
android:layout_width="40px"
android:layout_height="wrap_content"
android:text="/"
/>
<Button
android:id="@+id/mod"
android:layout_toRightOf="@id/div"
android:layout_width="40px"
android:layout_height="wrap_content"
android:text="%"
/>
<Button
android:id="@+id/four"
android:layout_below="@id/seven"
android:layout_width="40px"
android:layout_height="wrap_content"
android:text="4"
/>
<Button
android:id="@+id/five"
android:layout_toRightOf="@id/four"
android:layout_below="@id/eight"
android:layout_width="40px"
android:layout_height="wrap_content"
android:text="5"
/>
<Button
android:id="@+id/six"
android:layout_toRightOf="@id/five"
android:layout_below="@id/nine"
android:layout_width="40px"
android:layout_height="wrap_content"
android:text="6"
/>
<Button
android:id="@+id/mul"
android:layout_toRightOf="@id/six"
android:layout_below="@id/div"
android:layout_width="40px"
android:layout_height="wrap_content"
android:text="*"
/>
<Button
android:id="@+id/fenshu"
android:layout_toRightOf="@id/mul"
android:layout_below="@id/mod"
android:layout_width="40px"
android:layout_height="wrap_content"
android:text="1/x"
/>
<Button
android:id="@+id/one"
android:layout_below="@id/four"
android:layout_width="40px"
android:layout_height="wrap_content"
android:text="1"
/>
<Button
android:id="@+id/two"
android:layout_toRightOf="@id/one"
android:layout_below="@id/five"
android:layout_width="40px"
android:layout_height="wrap_content"
android:text="2"
/>
<Button
android:id="@+id/three"
android:layout_toRightOf="@id/two"
android:layout_below="@id/six"
android:layout_width="40px"
android:layout_height="wrap_content"
android:text="3"
/>
<Button
android:id="@+id/sub"
android:layout_toRightOf="@id/three"
android:layout_below="@id/mul"
android:layout_width="40px"
android:layout_height="wrap_content"
android:text="-"
/>
<Button
android:id="@+id/equal"
android:layout_toRightOf="@id/sub"
android:layout_below="@id/fenshu"
android:layout_width="40px"
android:layout_height="70px"
android:text="="
/>
<Button
android:id="@+id/zero"
android:layout_below="@id/one"
android:layout_width="80px"
android:layout_height="wrap_content"
android:text="0"
/>
<Button
android:id="@+id/point"
android:layout_toRightOf="@id/zero"
android:layout_below="@id/three"
android:layout_width="40px"
android:layout_height="wrap_content"
android:text="."
/>
<Button
android:id="@+id/add"
android:layout_toRightOf="@id/point"
android:layout_below="@id/sub"
android:layout_width="40px"
android:layout_height="wrap_content"
android:text="+"
/> </RelativeLayout>
第二个Activity布局:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" > <EditText
android:id="@+id/edt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/one"
/>
<Button
android:id="@+id/btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/edt"
android:text="返回"
/>
</LinearLayout>