Android studio制作简易计算器

好的，下面是制作简易计算器的步骤：

1. 打开Android Studio，创建一个新项目。

2. 在布局文件中添加一个EditText用于显示计算结果和多个Button用于输入数字和运算符。

3. 在MainActivity中获取EditText和Button的引用，并设置Button的点击事件。

4. 在点击事件中，根据按钮的标识符进行不同的计算，并将结果显示到EditText中。

5. 完成以上步骤后，就可以运行程序并测试计算器的功能了。

下面是一个简单的例子代码，供参考：

activity_main.xml：

<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:padding="16dp"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/result"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="16dp"
        android:layout_marginTop="16dp"
        android:hint="0"
        android:padding="16dp"
        android:textAlignment="textEnd"
        android:textSize="24sp" />

    <GridLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:rowCount="4"
        android:columnCount="4"
        android:layout_below="@id/result">

        <Button
            android:id="@+id/button_1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="1"
            android:textSize="24sp" />

        <Button
            android:id="@+id/button_2"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="2"
            android:textSize="24sp" />

        <Button
            android:id="@+id/button_3"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="3"
            android:textSize="24sp" />

        <Button
            android:id="@+id/button_add"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="+"
            android:textSize="24sp" />

        <Button
            android:id="@+id/button_4"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="4"
            android:textSize="24sp" />

        <Button
            android:id="@+id/button_5"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="5"
            android:textSize="24sp" />

        <Button
            android:id="@+id/button_6"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="6"
            android:textSize="24sp" />

        <Button
            android:id="@+id/button_subtract"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="-"
            android:textSize="24sp" />

        <Button
            android:id="@+id/button_7"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="7"
            android:textSize="24sp" />

        <Button
            android:id="@+id/button_8"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="8"
            android:textSize="24sp" />

        <Button
            android:id="@+id/button_9"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="9"
            android:textSize="24sp" />

        <Button
            android:id="@+id/button_multiply"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="*"
            android:textSize="24sp" />

        <Button
            android:id="@+id/button_clear"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:layout_gravity="fill"
            android:text="C"
            android:textSize="24sp" />

        <Button
            android:id="@+id/button_0"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="0"
            android:textSize="24sp" />

        <Button
            android:id="@+id/button_equal"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="="
            android:textSize="24sp" />

        <Button
            android:id="@+id/button_divide"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="/"
            android:textSize="24sp" />

    </GridLayout>

</RelativeLayout>

MainActivity.java：

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private EditText result;
    private Button button_0, button_1, button_2, button_3, button_4, button_5, button_6, button_7, button_8, button_9;
    private Button button_add, button_subtract, button_multiply, button_divide, button_clear, button_equal;
    private boolean isAddition, isSubtraction, isMultiplication, isDivision;
    private float value1, value2;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        result = findViewById(R.id.result);

        button_0 = findViewById(R.id.button_0);
        button_1 = findViewById(R.id.button_1);
        button_2 = findViewById(R.id.button_2);
        button_3 = findViewById(R.id.button_3);
        button_4 = findViewById(R.id.button_4);
        button_5 = findViewById(R.id.button_5);
        button_6 = findViewById(R.id.button_6);
        button_7 = findViewById(R.id.button_7);
        button_8 = findViewById(R.id.button_8);
        button_9 = findViewById(R.id.button_9);

        button_add = findViewById(R.id.button_add);
        button_subtract = findViewById(R.id.button_subtract);
        button_multiply = findViewById(R.id.button_multiply);
        button_divide = findViewById(R.id.button_divide);

        button_clear = findViewById(R.id.button_clear);
        button_equal = findViewById(R.id.button_equal);

        button_0.setOnClickListener(this);
        button_1.setOnClickListener(this);
        button_2.setOnClickListener(this);
        button_3.setOnClickListener(this);
        button_4.setOnClickListener(this);
        button_5.setOnClickListener(this);
        button_6.setOnClickListener(this);
        button_7.setOnClickListener(this);
        button_8.setOnClickListener(this);
        button_9.setOnClickListener(this);

        button_add.setOnClickListener(this);
        button_subtract.setOnClickListener(this);
        button_multiply.setOnClickListener(this);
        button_divide.setOnClickListener(this);

        button_clear.setOnClickListener(this);
        button_equal.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.button_0:
                result.setText(result.getText() + "0");
                break;
            case R.id.button_1:
                result.setText(result.getText() + "1");
                break;
            case R.id.button_2:
                result.setText(result.getText() + "2");
                break;
            case R.id.button_3:
                result.setText(result.getText() + "3");
                break;
            case R.id.button_4:
                result.setText(result.getText() + "4");
                break;
            case R.id.button_5:
                result.setText(result.getText() + "5");
                break;
            case R.id.button_6:
                result.setText(result.getText() + "6");
                break;
            case R.id.button_7:
                result.setText(result.getText() + "7");
                break;
            case R.id.button_8:
                result.setText(result.getText() + "8");
                break;
            case R.id.button_9:
                result.setText(result.getText() + "9");
                break;
            case R.id.button_add:
                if (result == null) {
                    result.setText("");
                } else {
                    value1 = Float.parseFloat(result.getText() + "");
                    isAddition = true;
                    result.setText(null);
                }
                break;
            case R.id.button_subtract:
                if (result == null) {
                    result.setText("");
                } else {
                    value1 = Float.parseFloat(result.getText() + "");
                    isSubtraction = true;
                    result.setText(null);
                }
                break;
            case R.id.button_multiply:
                if (result == null) {
                    result.setText("");
                } else {
                    value1 = Float.parseFloat(result.getText() + "");
                    isMultiplication = true;
                    result.setText(null);
                }
                break;
            case R.id.button_divide:
                if (result == null) {
                    result.setText("");
                } else {
                    value1 = Float.parseFloat(result.getText() + "");
                    isDivision = true;
                    result.setText(null);
                }
                break;
            case R.id.button_clear:
                result.setText("");
                break;
            case R.id.button_equal:
                value2 = Float.parseFloat(result.getText() + "");
                if (isAddition) {
                    result.setText(value1 + value2 + "");
                    isAddition = false;
                }
                if (isSubtraction) {
                    result.setText(value1 - value2 + "");
                    isSubtraction = false;
                }
                if (isMultiplication) {
                    result.setText(value1 * value2 + "");
                    isMultiplication = false;
                }
                if (isDivision) {
                    result.setText(value1 / value2 + "");
                    isDivision = false;
                }
                break;
        }
    }
}

这样，一个简单的计算器就完成了。