如何在Android studio(Java)中根据用户输入的条件显示可绘制的图形

public class MyView extends View {
    private int shapeType; // 用户输入的条件，用于确定要绘制的图形类型

    public MyView(Context context) {
        super(context);
    }

    public MyView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        
        // 根据用户输入的条件绘制相应的图形
        switch (shapeType) {
            case 1:
                drawRectangle(canvas);
                break;
            case 2:
                drawCircle(canvas);
                break;
            case 3:
                drawLine(canvas);
                break;
            // 可以根据需要添加更多的条件和对应的图形绘制方法
        }
    }

    private void drawRectangle(Canvas canvas) {
        // 绘制矩形
        Rect rect = new Rect(100, 100, 300, 300);
        Paint paint = new Paint();
        paint.setColor(Color.RED);
        canvas.drawRect(rect, paint);
    }

    private void drawCircle(Canvas canvas) {
        // 绘制圆形
        int centerX = getWidth() / 2;
        int centerY = getHeight() / 2;
        int radius = 200;
        Paint paint = new Paint();
        paint.setColor(Color.BLUE);
        canvas.drawCircle(centerX, centerY, radius, paint);
    }

    private void drawLine(Canvas canvas) {
        // 绘制线条
        Paint paint = new Paint();
        paint.setColor(Color.GREEN);
        paint.setStrokeWidth(5);
        canvas.drawLine(100, 100, 300, 300, paint);
    }

    public void setShapeType(int shapeType) {
        this.shapeType = shapeType;
        invalidate(); // 通知View组件重绘
    }
}

public class MainActivity extends AppCompatActivity {
    private EditText inputEditText;
    private Button drawButton;
    private MyView myView;

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

        inputEditText = findViewById(R.id.inputEditText);
        drawButton = findViewById(R.id.drawButton);
        myView = findViewById(R.id.myView);

        drawButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String input = inputEditText.getText().toString();
                int shapeType = Integer.parseInt(input);
                myView.setShapeType(shapeType);
            }
        });
    }
}