xml布局文件:
<LinearLayout 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:orientation="vertical"
tools:context="com.example.app.MainActivity" >
<EditText
android:id="@+id/editText_1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:editable="false"
android:gravity="right"
/>
<Button
android:id="@+id/delete"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right"
android:text="删除"
android:textSize="20sp"
/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:gravity="center_horizontal"
>
<Button
android:id="@+id/btn_7"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="7"
android:textSize="20sp"
/>
<Button
android:id="@+id/btn_8"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="8"
android:textSize="20sp"
/>
<Button
android:id="@+id/btn_9"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="9"
android:textSize="20sp"
/>
<Button
android:id="@+id/divide"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="/"
android:textSize="20sp"
/>
</LinearLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:gravity="center_horizontal"
>
<Button
android:id="@+id/btn_4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="4"
android:textSize="20sp"
/>
<Button
android:id="@+id/btn_5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="5"
android:textSize="20sp"
/>
<Button
android:id="@+id/btn_6"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="6"
android:textSize="20sp"
/>
<Button
android:id="@+id/multiply"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="*"
android:textSize="20sp"
/>
</LinearLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:gravity="center_horizontal"
>
<Button
android:id="@+id/btn_1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="1"
android:textSize="20sp"
/>
<Button
android:id="@+id/btn_2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="2"
android:textSize="20sp"
/>
<Button
android:id="@+id/btn_3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="3"
android:textSize="20sp"
/>
<Button
android:id="@+id/del"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="-"
android:textSize="20sp"
/>
</LinearLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:gravity="center_horizontal"
>
<Button
android:id="@+id/point"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="."
android:textSize="20sp"
/>
<Button
android:id="@+id/btn_0"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="0"
android:textSize="20sp"
/>
<Button
android:id="@+id/equals"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="="
android:textSize="20sp"
/>
<Button
android:id="@+id/add"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="+"
android:textSize="20sp"
/>
</LinearLayout>
</LinearLayout>
</LinearLayout>
源程序:
package com.example.app;
import android.app.Activity;
import android.os.Bundle;
import android.text.Editable;
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;
public class MainActivity extends Activity implements OnClickListener{
private Button delete;
private Button btn_1;
private Button btn_2;
private Button btn_3;
private Button btn_4;
private Button btn_5;
private Button btn_6;
private Button btn_7;
private Button btn_8;
private Button btn_9;
private Button point;
private Button divide;
private Button multiply;
private Button add;
private Button del;
private EditText editText;
private Button equals;
private Button btn_0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
editText = (EditText) findViewById(R.id.editText_1);
delete = (Button) findViewById(R.id.delete);
btn_0 = (Button) findViewById(R.id.btn_0);
btn_1 = (Button) findViewById(R.id.btn_1);
btn_2 = (Button) findViewById(R.id.btn_2);
btn_3 = (Button) findViewById(R.id.btn_3);
btn_4 = (Button) findViewById(R.id.btn_4);
btn_5 = (Button) findViewById(R.id.btn_5);
btn_6 = (Button) findViewById(R.id.btn_6);
btn_7 = (Button) findViewById(R.id.btn_7);
btn_8 = (Button) findViewById(R.id.btn_8);
btn_9 = (Button) findViewById(R.id.btn_9);
point = (Button) findViewById(R.id.point);
divide = (Button) findViewById(R.id.divide);
equals = (Button) findViewById(R.id.equals);
multiply = (Button) findViewById(R.id.multiply);
add = (Button) findViewById(R.id.add);
del = (Button) findViewById(R.id.del);
btn_0.setOnClickListener(this);
btn_1.setOnClickListener(this);
btn_2.setOnClickListener(this);
btn_3.setOnClickListener(this);
btn_4.setOnClickListener(this);
btn_5.setOnClickListener(this);
btn_6.setOnClickListener(this);
btn_7.setOnClickListener(this);
btn_8.setOnClickListener(this);
btn_9.setOnClickListener(this);
add.setOnClickListener(this);
delete.setOnClickListener(this);
del.setOnClickListener(this);
multiply.setOnClickListener(this);
equals.setOnClickListener(this);
divide.setOnClickListener(this);
point.setOnClickListener(this);
}
@Override
public void onClick(View v) {
String text = editText.getText().toString();
switch(v.getId()){
case R.id.btn_0:
case R.id.btn_1:
case R.id.btn_2:
case R.id.btn_3:
case R.id.btn_4:
case R.id.btn_5:
case R.id.btn_6:
case R.id.btn_7:
case R.id.btn_8:
case R.id.btn_9:
case R.id.point:
editText.setText(text+((Button) v).getText());
break;
case R.id.add:
case R.id.del:
case R.id.multiply:
case R.id.divide:
editText.setText(text+" "+((Button) v).getText()+" ");
break;
case R.id.delete:
if(text!=null&&!text.equals(""))
editText.setText(text.substring(0, text.length()-1));
break;
case R.id.equals:
getResult();
break;
}
}
private void getResult(){
String text = editText.getText().toString();
if(text==null||text.equals(" ")){
return;
}
if(!text.contains(" ")){
return;
}
double result;
String s1 = text.substring(0, text.indexOf(" "));
String oprate = text.substring(text.indexOf(" ")+1, text.indexOf(" ")+2);
String s2 = text.substring(text.indexOf(" ")+3);
if(!s1.equals("")&&!s2.equals("")){
double d1 = Double.parseDouble(s1);
double d2 = Double.parseDouble(s2);
if(d1==0){
if(oprate.equals("+")){
result = d2;
if(!s1.contains(".")&&!s2.contains(".")){
editText.setText((int)result+"");
}
editText.setText(result+"");
}
if(oprate.equals("*")){
result = 0;
editText.setText(result+"");
}
if(oprate.equals("/")){
result = 0;
editText.setText(result+"");
}
if(oprate.equals("-")){
result = 0-d2;
editText.setText(result+"");
}
}
if(oprate.equals("+")){
result = d1+d2;
if(!s1.contains(".")&&!s2.contains(".")){
editText.setText((int)result+"");
}
editText.setText(result+"");
}
if(oprate.equals("*")){
result = d1*d2;
editText.setText(result+"");
}
if(oprate.equals("/")){
result = d1/d2;
editText.setText(result+"");
}
if(oprate.equals("-")){
result = d1-d2;
editText.setText(result+"");
}
}
}
}