QML- Image在佈局中大小不能適應

在實際應用Image的過程中，發現加入佈局中以後Image的縮放就會有問題，即使指定了

fillMode:Image.PreserveAspectFit也會發現圖片顯示大小雖然得到了調整，但是實際在佈局中佔用的寬度並沒有調整

Rectangle{
    width: 800
    height: 600
    color: "white"
    RowLayout{
        Image {
            id:first
            Layout.preferredHeight: 16
            source: "qrc:/icon_sidebar_im_check.png"
            fillMode:Image.PreserveAspectFit
            horizontalAlignment: Image.AlignLeft
        }
        Image {
            id:second
            Layout.preferredHeight: 16
            source: "qrc:/icon_sidebar_im_check.png"
            fillMode:Image.PreserveAspectFit
            horizontalAlignment: Image.AlignLeft
        }
    }
}

效果如下:

仔細看過QML中的例子後發現，等比的縮放調節是根據Image的width和height屬性來調節的，那直接設置height:16

Rectangle{
    width: 800
    height: 600
    color: "white"
    RowLayout{
        Image {
            id:first
            Layout.preferredHeight: 16
            height:16
            source: "qrc:/icon_sidebar_im_check.png"
            fillMode:Image.PreserveAspectFit
            horizontalAlignment: Image.AlignLeft
        }
        Image {
            id:second
            Layout.preferredHeight: 16
            height:16
            source: "qrc:/icon_sidebar_im_check.png"
            fillMode:Image.PreserveAspectFit
            horizontalAlignment: Image.AlignLeft
        }
    }
}

 效果如下:

OK了。