android calculator realizes addition subtraction multiplication and division of two digits
- 2021-11-30 01:32:44
- OfStack
In this paper, we share the specific code of addition, subtraction, multiplication and division of android calculator for your reference, the specific contents are as follows
Note: The following calculator only pays attention to the realization function, does not consider other BUG, only two-digit integer algorithm operation, suitable for novice
1. Realize ideas
The numerical value obtained from the keyboard is placed in a character array, and the operation symbol (+-/) is used as the dividing point to separate the two numerical values and carry out algorithm operation. *
2. Difficulties
How to judge whether it is a symbol? +-×/
Where is the record symbol?
3. Steps:
1. Get the value entered by the keyboard
2. Store the value in an array of 1 characters
3. Traverse every number in the array. If you find the algorithm symbol, record the position of the algorithm symbol. (Key points, starting at 0)
4. Place the number before the algorithm symbol in a defined int type number
5. Same
6. Judge which method is addition, subtraction, multiplication and division, and then perform simple operation.
4. Code
i: Layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:weightSum="1"
>
<TextView android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/etResult"
android:layout_weight="0.05"
android:textSize="25dp"
android:paddingTop="10dp"
android:gravity="bottom"
android:hint="0.0"
/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_weight="0.8">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:weightSum="1">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="C"
android:textSize="25dp"
android:background="@color/colorWhite"
android:id="@+id/btnQingchu"
android:layout_weight="0.5" />
<Button
android:layout_width="235dp"
android:layout_height="wrap_content"
android:text=" " "
android:textSize="25dp"
android:background="@color/colorBlue"
android:id="@+id/btnHuishan"
android:layout_weight="0.5"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btn7"
android:text="7"
android:textSize="25dp"
android:layout_weight="0.25"
/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btn8"
android:text="8"
android:textSize="25dp"
android:layout_weight="0.25"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btn9"
android:text="9"
android:textSize="25dp"
android:layout_weight="0.25"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btnChu"
android:text=" ÷ "
android:textSize="25dp"
android:background="@color/colorBlue"
android:layout_weight="0.25"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btn4"
android:text="4"
android:textSize="25dp"
android:layout_weight="0.25"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btn5"
android:text="5"
android:textSize="25dp"
android:layout_weight="0.25"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btn6"
android:text="6"
android:textSize="25dp"
android:layout_weight="0.25"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btnCheng"
android:text=" × "
android:textSize="25dp"
android:background="@color/colorBlue"
android:layout_weight="0.25"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btn1"
android:text="1"
android:textSize="25dp"
android:layout_weight="0.25"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btn2"
android:text="2"
android:textSize="25dp"
android:layout_weight="0.25"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btn3"
android:text="3"
android:textSize="25dp"
android:layout_weight="0.25"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btnJian"
android:text=" - "
android:textSize="25dp"
android:background="@color/colorBlue"
android:layout_weight="0.25"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btn0"
android:text="0"
android:textSize="25dp"
android:layout_weight="0.25"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btnDian"
android:text="."
android:textSize="25dp"
android:layout_weight="0.25"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btnDengyu"
android:text="="
android:textSize="25dp"
android:layout_weight="0.25"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btnJia"
android:text=" + "
android:textSize="25dp"
android:background="@color/colorBlue"
android:layout_weight="0.25"/>
</LinearLayout>
</LinearLayout>
</LinearLayout>ii: Get keyboard value, write monitor
public void getButton(){
// Get Button Component
btn0= (Button) findViewById(R.id.btn0);
btn1= (Button) findViewById(R.id.btn1);
btn2= (Button) findViewById(R.id.btn2);
btn3= (Button) findViewById(R.id.btn3);
btn4= (Button) findViewById(R.id.btn4);
btn5= (Button) findViewById(R.id.btn5);
btn6= (Button) findViewById(R.id.btn6);
btn7= (Button) findViewById(R.id.btn7);
btn8= (Button) findViewById(R.id.btn8);
btn9= (Button) findViewById(R.id.btn9);
btnJia= (Button) findViewById(R.id.btnJia);
btnJian= (Button) findViewById(R.id.btnJian);
btnCheng= (Button) findViewById(R.id.btnCheng);
btnChu= (Button) findViewById(R.id.btnChu);
btnDian= (Button) findViewById(R.id.btnDian);
btnDengyu= (Button) findViewById(R.id.btnDengyu);
btnQingchu= (Button) findViewById(R.id.btnQingchu);
btnHuishan= (Button) findViewById(R.id.btnHuishan);
etGet = (TextView) findViewById(R.id.etResult);
// Binding monitoring
btn0.setOnClickListener(this);
btn1.setOnClickListener(this);
btn2.setOnClickListener(this);
btn3.setOnClickListener(this);
btn4.setOnClickListener(this);
btn5.setOnClickListener(this);
btn6.setOnClickListener(this);
btn7.setOnClickListener(this);
btn8.setOnClickListener(this);
btn9.setOnClickListener(this);
btnJia.setOnClickListener(this);
btnJian.setOnClickListener(this);
btnCheng.setOnClickListener(this);
btnChu.setOnClickListener(this);
btnDian.setOnClickListener(this);
btnDengyu.setOnClickListener(this);
btnQingchu.setOnClickListener(this);
btnHuishan.setOnClickListener(this);
}iii: Bind Button
@Override
public void onClick(View v) {
str = etGet.getText().toString();
switch (v.getId()){
// Digital button
case R.id.btn0:
case R.id.btn1:
case R.id.btn2:
case R.id.btn3:
case R.id.btn4:
case R.id.btn5:
case R.id.btn6:
case R.id.btn7:
case R.id.btn8:
case R.id.btn9:
/* if (b_Clean)
{
b_Clean =false;
etGet.setText("");
}*/
etGet.setText(str+((Button)v).getText());
break;
// Operation button
case R.id.btnJia:
case R.id.btnJian:
case R.id.btnCheng:
case R.id.btnChu:
case R.id.btnDian:
/* if (b_Clean)
{
b_Clean =false;
etGet.setText("");
}*/
etGet.setText(str+((Button)v).getText());
break;
// Clear button
case R.id.btnQingchu:
/* if (b_Clean)
{
b_Clean =false;
etGet.setText("");
}*/
etGet.setText("");
break;
case R.id.btnDengyu:
getResult();
break;
case R.id.btnHuishan:
str=etGet.getText().toString();
try {
etGet.setText(str.substring(0,str.length()-1));
}
catch (Exception e){
etGet.setText("");
}
break;
}
}iV: Algorithm Function Implementation
public void getResult(){
str = etGet.getText().toString();
strArray = new String[str.length()]; // Place the resulting string in the 1 In an array of characters
//System.out.println("str"+str);
int n=0;
for(int i=0; i<strArray.length;i++){
strArray[i] = str.substring(i, i+1); // Traversing each element of the array
//System.out.print(strArray[i]);
if(strArray[i].equals(" + ")||strArray[i].equals(" - ") // Satisfy the condition
||strArray[i].equals(" × ")||strArray[i].equals(" ÷ "))
{
n= i; // Record the location where the symbol exists
}
}
int num1 = Integer.parseInt(str.substring(0,n)); // Before getting 1 String number
String caculate = str.substring(n,n+1); // Get algorithm symbols, add, subtract, multiply and divide
int num2 = Integer.parseInt(str.substring(n+1)); // After getting 1 String number
if (caculate.equals(" + "))
{
Inputresult = num1+num2;
}
else if (caculate.equals(" - "))
{
Inputresult = num1-num2;
}
else if (caculate.equals(" × "))
{
Inputresult = num1*num2;
}
else if (caculate.equals(" ÷ "))
{
if (num2==0)
{
return ;
}
Inputresult = num1/num2;
}
etGet.setText(num1+caculate+num2+"="+Inputresult);
}For more calculator functions, please click on the topic: Calculator Function Summary to learn
About the Android calculator function realization, check the topic: Android calculator for learning.