Android CheckBox与Spanned双重响应

一、问题描述

客户端注册账号，需要用户确认用户协议及可以查看协议。选择使用单CheckBox控件配合SpannableString。
但是遇到了一个问题，点击链接后CheckBox也响应了Click导致CheckBox勾选状态改变，这是不期望发生的。

二、问题原因

点击事件，从TextView的onTouchEvent入手

@Override
@Override
public boolean onTouchEvent(TextView widget, Spannable buffer,
        MotionEvent event) {
    
    
    int action = event.getAction();

    if (action == MotionEvent.ACTION_UP ||
            action == MotionEvent.ACTION_DOWN) {
    
    
        int x = (int) event.getX();
        int y = (int) event.getY();

        x -= widget.getTotalPaddingLeft();
        y -= widget.getTotalPaddingTop();

        x += widget.getScrollX();
        y += widget.getScrollY();

        Layout layout = widget.getLayout();
        int line = layout.getLineForVertical(y);
        int off = layout.getOffsetForHorizontal(line, x);

        ClickableSpan[] link = buffer.getSpans(off, off, ClickableSpan.class);

        if (link.length != 0) {
    
    
            if (action == MotionEvent.ACTION_UP) {
    
    
                link[0].onClick(widget);
            } else if (action == MotionEvent.ACTION_DOWN) {
    
    
                Selection.setSelection(buffer,
                        buffer.getSpanStart(link[0]),
                        buffer.getSpanEnd(link[0]));
            }

            return true;
        } else {
    
    
            Selection.removeSelection(buffer);
        }
    }

    return super.onTouchEvent(widget, buffer, event);
}

link[0].onClick(widget);
调用了我们代码中ClickableSpan的onClick方法

三、解决问题

在TextView的onTouchEvent执行前，拦截ACTION_UP方法，并修改为ACTION_CANCEL，避免触发控件performClick

checkBox.setOnTouchListener(new View.OnTouchListener() {
    
    
    @Override
        public boolean onTouch(View v, MotionEvent event) {
    
    
            if (v instanceof TextView) {
    
    
                TextView text = (TextView) v;
                MovementMethod method = text.getMovementMethod();
                if (method != null && text.getText() instanceof Spannable
                        && event.getAction() == MotionEvent.ACTION_UP) {
    
    
                    if (method.onTouchEvent(text, (Spannable) text.getText(), event)) {
    
    
                        event.setAction(MotionEvent.ACTION_CANCEL);
                    }
                }
            }
            return false;
        }
});