简易计算器

今天做了个简易计算器，先看看效果，嘿嘿。。。。。。。

加法：

 

 

减法：

乘法：

除法：

布局代码：

    <TableLayout xmlns:android="http://schemas.android.com/apk/res/android"        android:layout_width="fill_parent"        android:layout_height="fill_parent" >        <TableRow>            <EditText                 android:id="@+id/num1"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                />             <TextView                 android:id="@+id/fuhao"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                />            <EditText                android:id="@+id/num2"                android:layout_width="wrap_content"                android:layout_height="wrap_content"            />            <TextView android:text="="                android:layout_width="wrap_content"                android:layout_height="wrap_content"                />                        <TextView                 android:id="@+id/result"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                />                    </TableRow>                        <TableRow><Button    android:id="@+id/button1"    android:layout_width="50dip"    android:layout_height="30dip"    android:text="+"     />            <Button    android:id="@+id/button2"    android:layout_width="50dip"    android:layout_height="30dip"    android:text="-"     />            <Button    android:id="@+id/button3"    android:layout_width="50dip"    android:layout_height="30dip"    android:text="*"     />            <Button    android:id="@+id/button4"    android:layout_width="50dip"    android:layout_height="30dip"    android:text="/"     /> </TableRow>    </TableLayout>

java类

 

package wn.stu.calculator;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 CalculatorActivity extends Activity {private EditText num1;private EditText num2;private TextView fuhao;private TextView result;private Button button1;private Button button2;private Button button3;private Button button4;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_calculator);                num1=(EditText) this.findViewById(R.id.num1);        num2=(EditText) this.findViewById(R.id.num2);        fuhao=(TextView) this.findViewById(R.id.fuhao);        result=(TextView) this.findViewById(R.id.result);        button1=(Button) this.findViewById(R.id.button1);        button2=(Button) this.findViewById(R.id.button2);        button3=(Button) this.findViewById(R.id.button3);        button4=(Button) this.findViewById(R.id.button4);        button1.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {float number1=Integer.parseInt(num1.getEditableText().toString());float number2=Integer.parseInt(num2.getEditableText().toString());fuhao.setText("        +");float r=number1+number2;System.out.println(r);result.setText(""+r);}});                button2.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {float number1=Integer.parseInt(num1.getEditableText().toString());float number2=Integer.parseInt(num2.getEditableText().toString());fuhao.setText("      -");float r=number1-number2;result.setText(""+r);System.out.println(r);}});        button3.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {float number1=Integer.parseInt(num1.getEditableText().toString());float number2=Integer.parseInt(num2.getEditableText().toString());fuhao.setText("      *");float r=number1*number2;result.setText(""+r);System.out.println(r);}});        button4.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {float number1=Integer.parseInt(num1.getEditableText().toString());float number2=Integer.parseInt(num2.getEditableText().toString());fuhao.setText("     /");float r=number1/number2;result.setText(""+r);System.out.println(r);}});    }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        getMenuInflater().inflate(R.menu.activity_calculator, menu);        return true;    }}

得到的r的类型是float，而setText（）；要string类型的，" "+r相当于String.valueOf(int   r);

开始我在布局中button设置的大小是80dip，50dip，但是显示不出来第五个组件，改小之后就可以了。