改变PopupWindow的重力

Question

我有一个必须显示弹出窗口的按钮.并且弹出窗口必须与按钮的右侧对齐.我就是这样做的.

button.setOnClickListener( new View.OnClickListener() {
    @Override
    public void onClick( final View view ) {
        if(popup == null) {
            final View view = getLayoutInflater().inflate(R.layout.popup, null);
            popup = new PopupWindow(view);
        }

        if(popup.isShowing()) {
            popup.dismiss();
        } else {
            popup.setInputMethodMode(PopupWindow.INPUT_METHOD_NEEDED);
            popup.setFocusable(true);
            popup.setWindowLayoutMode(ViewGroup.LayoutParams.WRAP_CONTENT,
                ViewGroup.LayoutParams.WRAP_CONTENT);
            popup.showAsDropDown(button, 0, 0);
        }
    }
} );

此代码工作正常,但弹出窗口与按钮的左侧对齐.有没有一种简单的方法来改变PopupWindow的引力？

Answer 1

我发现最简单的方法是指定x-offset参数:

final View view = popup.getContentView();
view.measure(View.MeasureSpec.UNSPECIFIED, View.MeasureSpec.UNSPECIFIED);
popup.showAsDropDown(button, button.getWidth() - view.getMeasuredWidth(), 0);