自定义一个右上角带数字的 RadioButton 给出具体的代码

您好，以下是一个自定义的右上角带数字的RadioButton的代码示例，供您参考：

public class BadgeRadioButton extends RadioButton {
    // 数字的画笔
    private Paint mBadgePaint;
    // 数字的颜色
    private int mBadgeColor;
    // 数字的文本
    private String mBadgeText;
    // 数字的文本颜色
    private int mBadgeTextColor;
    // 数字的文本大小
    private float mBadgeTextSize;
    // 数字的文本边距
    private float mBadgePadding;
    // 数字的半径
    private float mBadgeRadius;
    // 数字的X轴偏移量
    private float mBadgeOffsetX;
    // 数字的Y轴偏移量
    private float mBadgeOffsetY;

    public BadgeRadioButton(Context context) {
        super(context);
        init(context, null);
    }

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

    public BadgeRadioButton(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs);
    }

    private void init(Context context, AttributeSet attrs) {
        mBadgePaint = new Paint();
        mBadgePaint.setAntiAlias(true);
        mBadgeColor = Color.RED;
        mBadgeTextColor = Color.WHITE;
        mBadgeTextSize = sp2px(context, 10);
        mBadgePadding = dp2px(context, 2);
        mBadgeRadius = dp2px(context, 6);
        mBadgeOffsetX = dp2px(context, 16);
        mBadgeOffsetY = dp2px(context, 4);

        if (attrs != null) {
            TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.BadgeRadioButton);
            mBadgeColor = ta.getColor(R.styleable.BadgeRadioButton_badge_color, Color.RED);
            mBadgeTextColor = ta.getColor(R.styleable.BadgeRadioButton_badge_text_color, Color.WHITE);
            mBadgeTextSize = ta.getDimension(R.styleable.BadgeRadioButton_badge_text_size, sp2px(context, 10));
            mBadgePadding = ta.getDimension(R.styleable.BadgeRadioButton_badge_padding, dp2px(context, 2));
            mBadgeRadius = ta.getDimension(R.styleable.BadgeRadioButton_badge_radius, dp2px(context, 6));
            mBadgeOffsetX = ta.getDimension(R.styleable.BadgeRadioButton_badge_offset_x, dp2px(context, 16));
            mBadgeOffsetY = ta.getDimension(R.styleable.BadgeRadioButton_badge_offset_y, dp2px(context, 4));
            mBadgeText = ta.getString(R.styleable.BadgeRadioButton_badge_text);
            ta.recycle();
        }
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        if (mBadgeText != null && mBadgeText.length() > 0) {
            mBadgePaint.setColor(mBadgeColor);
            Rect rect = new Rect();
            mBadgePaint.setTextSize(mBadgeTextSize);
            mBadgePaint.getTextBounds(mBadgeText, 0, mBadgeText.length(), rect);
            float textWidth = mBadgePaint.measureText(mBadgeText);
            float badgeWidth = textWidth + 2 * mBadgePadding;
            float badgeHeight = rect.height() + 2 * mBadgePadding;
            float x = getMeasuredWidth() / 2 + mBadgeOffsetX;
            float y = mBadgeOffsetY;
            canvas.drawRoundRect(x - badgeWidth / 2, y, x + badgeWidth / 2, y + badgeHeight, mBadgeRadius, mBadgeRadius, mBadgePaint);
            mBadgePaint.setColor(mBadgeTextColor);
            mBadgePaint.setTextAlign(Paint.Align.CENTER);
            canvas.drawText(mBadgeText, x, y + badgeHeight - mBadgePadding - rect.bottom, mBadgePaint);
        }
    }

    /**
     * 设置数字文本
     */
    public void setBadgeText(String text) {
        mBadgeText = text;
        invalidate();
    }

    /**
     * 设置数字文本颜色
     */
    public void setBadgeTextColor(int color) {
        mBadgeTextColor = color;
        invalidate();
    }

    /**
     * 设置数字文本大小
     */
    public void setBadgeTextSize(float size) {
        mBadgeTextSize = size;
        invalidate();
    }

    /**
     * 设置数字文本边距
     */
    public void setBadgePadding(float padding) {
        mBadgePadding = padding;
        invalidate();
    }

    /**
     * 设置数字半径
     */
    public void setBadgeRadius(float radius) {
        mBadgeRadius = radius;
        invalidate();
    }

    /**
     * 设置数字X轴偏移量
     */
    public void setBadgeOffsetX(float offsetX) {
        mBadgeOffsetX = offsetX;
        invalidate();
    }

    /**
     * 设置数字Y轴偏移量
     */
    public void setBadgeOffsetY(float offsetY) {
        mBadgeOffsetY = offsetY;
        invalidate();
    }

    private float dp2px(Context context, float dp) {
        return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, context.getResources().getDisplayMetrics());
    }

    private float sp2px(Context context, float sp) {
        return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, sp, context.getResources().getDisplayMetrics());
    }
}

请注意，这个自定义的RadioButton包含了一些自定义属性，例如`badge_color`、`badge_text_color`、`badge_text_size`等，您可以在xml布局文件中进行设置。具体示例代码如下：

<com.example.BadgeRadioButton
    android:id="@+id/radio_button"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="RadioButton"
    app:badge_color="#FF0000"
    app:badge_text_color="#FFFFFF"
    app:badge_text_size="10sp"
    app:badge_padding="2dp"
    app:badge_radius="6dp"
    app:badge_offset_x="16dp"
    app:badge_offset_y="4dp"/>

以上仅供参考，您可以根据自己的实际需要进行调整和修改。