Flutter將圖標按鈕對齊到行中的右側

這是我的密碼；

SizedBox(
        width: size.width,
        child: Row(
          children: [
            Padding(
              padding: const EdgeInsets.only(left: 10, bottom: 10, top: 10),
              child: ClipRRect(
                borderRadius: BorderRadius.circular(100),
                child: Image.asset(
                  'assets/images/me.png',
                  height: 30,
                  width: 30,
                  fit: BoxFit.cover,
                ),
              ),
            ),
            const Padding(
              padding: EdgeInsets.only(left: 10),
              child: Text(
                'samet',
                textAlign: TextAlign.center,
                style: TextStyle(fontSize: 16),
              ),
            ),
            IconButton(
              // padding: const EdgeInsets.only(left: 250),
              onPressed: () {},
              icon: const Icon(Icons.more_horiz),
              iconSize: 30,
              alignment: Alignment.centerRight,
              splashColor: Colors.transparent,
              highlightColor: Colors.transparent,
            )
          ],
        ),
      ),

這里是輸出；

我查看了其他StackOverflow問題，但找不到答案。我不能用onPressed功能更改圖標Button的顏色。我創建了Color _color的變量，并使iconButton屬性Color＝{@112}，在onPressed中我打開了setState函數，當我按下時它不會改變。

IconButton(
              // padding: const EdgeInsets.only(left: 250),
              color: _iconColor,
              onPressed: () {
                setState(() {
                  _iconColor = Colors.red;
                });
              },
              icon: const Icon(Icons.more_horiz),
              iconSize: 30,
              alignment: Alignment.centerRight,
              splashColor: Colors.transparent,
              highlightColor: Colors.transparent,
            )