我正在尝试为 android 制作一个简单的计算器应用程序，但我现在被卡住了。我打算制作 2 个计算器（一个基本的，另一个更高级的，类似于 Windows 内置的）。这个想法是把它分成3个不同的班级。
两个类将包含“主”代码（按钮、布局），最后一个类应包含我计划调用的函数（如加法、乘法）。我设法在一堂课上完成了两个计算器，但我不知道如何让它们调用另一堂课的函数。
问题：我设法创建了基本计算器，它可以调用其他类的函数，但是如果我想一个接一个地添加更多计算，它就无法正常工作。我的意思是：假设我的第一个数字是 1，我的第二个数字是 3。它打印结果 4，但如果我再次单击添加并输入 2，它会打印结果 5 而不是 6。不知何故，它将第二个变量存储到第一个，我不知道为什么:(有人可以帮我吗？提前谢谢
enter code here
package com.example.simcalc;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainInterface extends Activity implements OnClickListener {
static EditText disp;
static TextView txt1, txt2;
SimFunctions sm;
TextView tx1;
Button btDot, bt1, bt2, bt3, bt4, bt5, bt6, bt7 ,bt8, bt9, bt0, btPlus, btMinus, btDivide, btMult,btEquals, btC;
float num2 =0 , res;
float num1 = 0;
String saveNumber = "";
static char sim ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main_interface);
disp = (EditText) findViewById(R.id.enterNumber);
bt1 = (Button) findViewById(R.id.one);
bt2 = (Button) findViewById(R.id.two);
bt3 = (Button) findViewById(R.id.three);
bt4 = (Button) findViewById(R.id.four);
bt5 = (Button) findViewById(R.id.five);
bt6 = (Button) findViewById(R.id.six);
bt7 = (Button) findViewById(R.id.seven);
bt8 = (Button) findViewById(R.id.eight);
bt9 = (Button) findViewById(R.id.nine);
bt0 = (Button) findViewById(R.id.zero);
btPlus = (Button) findViewById(R.id.add);
btMinus = (Button) findViewById(R.id.sub);
btMult = (Button) findViewById(R.id.mult);
btDivide = (Button) findViewById(R.id.div);
btC = (Button) findViewById (R.id.can);
btDot = (Button) findViewById(R.id.decimal);
btEquals = (Button) findViewById(R.id.equal);
txt1 = (TextView) findViewById(R.id.textView1);
txt2 = (TextView) findViewById(R.id.textView2);
bt1.setOnClickListener(this);
bt2.setOnClickListener(this);
bt3.setOnClickListener(this);
bt4.setOnClickListener(this);
bt5.setOnClickListener(this);
bt6.setOnClickListener(this);
bt7.setOnClickListener(this);
bt8.setOnClickListener(this);
bt9.setOnClickListener(this);
bt0.setOnClickListener(this);
btPlus.setOnClickListener(this);
btMinus.setOnClickListener(this);
btDivide.setOnClickListener(this);
btMult.setOnClickListener(this);
btC.setOnClickListener(this);
btDot.setOnClickListener(this);
btEquals.setOnClickListener(this);
disp.setText("0");
sm = new SimFunctions();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main_interface, menu);
return true;
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()){
case R.id.one:
saveNumber += "1";
disp.setText(saveNumber);
break;
case R.id.two:
saveNumber += "2";
disp.setText(saveNumber);
break;
case R.id.three:
saveNumber += "3";
disp.setText(saveNumber);
break;
case R.id.four:
saveNumber += "4";
disp.setText(saveNumber);
break;
case R.id.five:
saveNumber += "5";
disp.setText(saveNumber);
break;
case R.id.six:
saveNumber += "6";
disp.setText(saveNumber);
break;
case R.id.seven:
saveNumber += "7";
disp.setText(saveNumber);
break;
case R.id.eight:
saveNumber += "8";
disp.setText(saveNumber);
break;
case R.id.nine:
saveNumber += "9";
disp.setText(saveNumber);
break;
case R.id.zero:
saveNumber += "0";
disp.setText(saveNumber);
break;
case R.id.decimal:
if (saveNumber.contains(".")){
break;
}
else{
saveNumber += ".";
disp.setText(saveNumber);
break;
}
case R.id.mult:
sim = '*';
if (saveNumber != ""){
num1 = Float.parseFloat(saveNumber);
saveNumber = "";
break;}
else{
break;}
case R.id.add:
sim = '+';
if (saveNumber != ""){
num1 = Float.parseFloat(saveNumber);
saveNumber = "";
break;}
else{
break;}
case R.id.div:
sim = '/';
if (saveNumber != ""){
num1 = Float.parseFloat(saveNumber);
saveNumber = "";
break;}
else{
break;}
case R.id.sub:
sim = '-';
if (saveNumber != ""){
num1 = Float.parseFloat(saveNumber);
saveNumber = "";
break;}
else{
break;}
case R.id.equal:
sm.equals(num1, saveNumber, sim);
break;
case R.id.can:
saveNumber = "";
disp.setText(saveNumber);
break;
}
}
}
package com.example.simcalc;
import android.app.Activity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class SimFunctions extends MainInterface {
public void equals(float num1, String saveNumber, char simbol){
String ds = "";
if ( saveNumber != "") {
try{
num2 = Float.parseFloat(saveNumber);}
catch(NumberFormatException e){
e.printStackTrace();
}
}
else {
num2 = 0;}
switch (simbol){
case ('*'):
res = num1 * num2;
num1 = res;
ds = Float.toString(res);
disp.setText(ds);
saveNumber = "";
ds = "";
break;
case ('+'):
ds = Float.toString(num1);
txt1.setText(ds);
ds = Float.toString(num2);
txt2.setText(ds);
res = num1 + num2;
num1 = res;
ds = Float.toString(res);
disp.setText(ds);
saveNumber = "";
ds = "";
break;
case ('/'):
res = num1 / num2;
num1 = res;
ds = Float.toString(res);
disp.setText(ds);
saveNumber = "";`enter code here`
ds = "";
break;
enter code here
case ('-'):
res = num1 - num2;
num1 = res;
ds = Float.toString(res);
disp.setText(ds);
saveNumber = "";
ds = "";
break;
}
}
}
<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:background="@color/testBlack"
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=".MainInterface" >
<EditText
android:id="@+id/enterNumber"
android:layout_width="match_parent"
android:layout_height="110dp"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:background="@color/scoreColor"
android:inputType="numberDecimal" />
<LinearLayout
android:id="@+id/linearLayout1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/linearLayout2"
android:layout_alignParentBottom="true"
android:layout_marginBottom="86dp"
android:gravity="center"
android:orientation="horizontal"
android:paddingTop="20dp" >
<Button
android:id="@+id/seven"
android:layout_width="55dp"
android:layout_height="wrap_content"
android:text="7" />
<Button
android:id="@+id/eight"
android:layout_width="55dp"
android:layout_height="wrap_content"
android:text="8" />
<Button
android:id="@+id/nine"
android:layout_width="55dp"
android:layout_height="wrap_content"
android:text="9" />
<Button
android:id="@+id/div"
android:layout_width="55dp"
android:layout_height="wrap_content"
android:text="/" />
</LinearLayout>
<LinearLayout
android:id="@+id/linearLayout2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_above="@+id/linearLayout1"
android:layout_alignLeft="@+id/enterNumber"
android:gravity="center"
android:orientation="horizontal"
android:paddingTop="20dp" >
<Button
android:id="@+id/four"
android:layout_width="55dp"
android:layout_height="wrap_content"
android:text="4" />
<Button
android:id="@+id/five"
android:layout_width="55dp"
android:layout_height="wrap_content"
android:text="5" />
<Button
android:id="@+id/six"
android:layout_width="55dp"
android:layout_height="wrap_content"
android:text="6" />
<Button
android:id="@+id/mult"
android:layout_width="55dp"
android:layout_height="wrap_content"
android:text="*" />
</LinearLayout>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/linearLayout2"
android:layout_below="@+id/enterNumber"
android:layout_marginTop="20dp"
android:gravity="center"
android:orientation="horizontal"
android:paddingTop="20dp" >
<Button
android:id="@+id/one"
android:layout_width="55dp"
android:layout_height="wrap_content"
android:text="1" />
<Button
android:id="@+id/two"
android:layout_width="55dp"
android:layout_height="wrap_content"
android:text="2" />
<Button
android:id="@+id/three"
android:layout_width="55dp"
android:layout_height="wrap_content"
android:text="3" />
<Button
android:id="@+id/sub"
android:layout_width="55dp"
android:layout_height="wrap_content"
android:text="-" />
</LinearLayout>
<LinearLayout
android:id="@+id/linearLayout3"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/linearLayout1"
android:layout_alignParentBottom="true"
android:gravity="center"
android:orientation="horizontal"
android:paddingTop="20dp" >
<Button
android:id="@+id/can"
android:layout_width="55dp"
android:layout_height="wrap_content"
android:text="c" />
<Button
android:id="@+id/zero"
android:layout_width="55dp"
android:layout_height="wrap_content"
android:text="0" />
<Button
android:id="@+id/equal"
android:layout_width="55dp"
android:layout_height="wrap_content"
android:text="=" />
<Button
android:id="@+id/add"
android:layout_width="55dp"
android:layout_height="wrap_content"
android:text="+" />
<Button
android:id="@+id/decimal"
android:layout_width="55dp"
android:layout_height="wrap_content"
android:text="." />
</LinearLayout>
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="@+id/linearLayout3"
android:layout_alignParentLeft="true"
android:text="Small Text"
android:textAppearance="?android:attr/textAppearanceSmall" />
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="@+id/linearLayout3"
android:layout_toRightOf="@+id/textView1"
android:text="TextView" />
</RelativeLayout>