android开发之实现简单计算器

Posted 2023-02-28 不会coding的小白

布局代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#87CEEB">
    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/my_edit1"
        android:text=""
        android:inputType="numberDecimal" />
    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/my_edit2"
        android:text=""
        android:inputType="numberDecimal" />
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/my_text"
        android:textSize = "20sp"
        android:textColor ="#0000FF"
        android:text = "=  "    />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/bt_add"
        android:text="加(+)"
        android:onClick="add"/>
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/bt_sub"
        android:text="减(-)" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="乘(×)"
        android:id="@+id/bt_muti" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="除(÷)"
        android:id="@+id/bt_div" />

</LinearLayout>

MainActivity

public class MainActivity extends AppCompatActivity implements View.OnClickListener 
    TextView tText;
    EditText tEdit_1,tEdit_2;
    Button btAdd,btSub,btMuti,btDiv;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.jisuanqi);
        tText = (TextView)findViewById(R.id.my_text);
        tEdit_1 = (EditText)findViewById(R.id.my_edit1);
        tEdit_2 = (EditText)findViewById(R.id.my_edit2);
        btAdd = (Button)findViewById(R.id.bt_add);
        btSub = (Button)findViewById(R.id.bt_sub);
        btMuti = (Button)findViewById(R.id.bt_muti);
        btDiv = (Button)findViewById(R.id.bt_div);
        btSub.setOnClickListener(new mysub());
        btMuti.setOnClickListener(new View.OnClickListener() 
            @Override
            public void onClick(View view) 
                String s1=tEdit_1.getText().toString();
                String s2=tEdit_2.getText().toString();
                if(view==btMuti) 
                    computer(s1,s2,'*');
                
            
        );
        btDiv.setOnClickListener(this);
    
    
    @Override
    public void onClick(View view) 
        String s1=tEdit_1.getText().toString();
        String s2=tEdit_2.getText().toString();
        if(view== btDiv) 
            computer(s1,s2,'/');
        
    
    
    class mysub implements View.OnClickListener
        @Override
        public void onClick(View view) 
            String s1=tEdit_1.getText().toString();
            String s2=tEdit_2.getText().toString();
            if(view==btSub) 
                computer(s1,s2,'-');
            
        
    
    
    public void add(View view) 
        String s1=tEdit_1.getText().toString();
        String s2=tEdit_2.getText().toString();
        if(view==btAdd) 
            computer(s1,s2,'+');
        
    
    
    void computer(String s1,String s2,char op)
        double n1=1,n2=1,result=1;
        n1 =Double.parseDouble(s1);
        n2 =Double.parseDouble(s2);
        switch(op) 
            case '+':  result = n1+n2; break;
            case '-':  result = n1-n2; break;
            case '*':  result = n1*n2; break;
            case '/':  result = n1/n2; break;
        
        tText.setText("="+result);
    

运行效果

运行效果如下：