Canvas { id: canvas // ... Rectangle { id: rect x: 100 y: 100 width: 50 height: 50 color: "red" property bool selected: false MouseArea { anchors.fill: parent onClicked: { rect.selected = true; } } onSelectedChanged: { if (selected) { var selectionBox = canvas.createSelectionBox(rect); selectionBox.rotation = rect.rotation; selectionBox.scaleX = rect.scaleX; selectionBox.scaleY = rect.scaleY; } else { canvas.removeSelectionBox(rect); } } } Rectangle { id: selectionBox color: "transparent" border.color: "blue" border.width: 2 visible: false rotation: 0 scaleX: 1 scaleY: 1 } function createSelectionBox(item) { if (item.parent === canvas) { selectionBox.x = item.x - 5; selectionBox.y = item.y - 5; selectionBox.width = item.width + 10; selectionBox.height = item.height + 10; selectionBox.visible = true; canvas.setChildIndex(selectionBox, canvas.children.length - 1); return selectionBox; } } function removeSelectionBox(item) { if (selectionBox.parent === canvas) { selectionBox.visible = false; } }}代码中的scaleX与scaleY被认定为不合法的定义，应该如何处理

在这段代码中，scaleX和scaleY被认为是不合法的定义，是因为Canvas并没有这两个属性。如果你想要给Canvas设置缩放比例，可以使用scale属性。

如果你想要在Canvas中创建一个带缩放和旋转的选择框，你可以为Canvas添加一个transform属性，然后将缩放和旋转应用到选择框上。

下面是修改后的代码示例：

Canvas {
    id: canvas
    // ...
    transform: Scale {
        id: canvasScale
        xScale: 1
        yScale: 1
    }
    Rectangle {
        id: rect
        x: 100
        y: 100
        width: 50
        height: 50
        color: "red"
        property bool selected: false
        MouseArea {
            anchors.fill: parent
            onClicked: {
                rect.selected = true;
            }
        }
        onSelectedChanged: {
            if (selected) {
                var selectionBox = canvas.createSelectionBox(rect);
                selectionBox.transform = canvasScale;
            } else {
                canvas.removeSelectionBox(rect);
            }
        }
    }
    Rectangle {
        id: selectionBox
        color: "transparent"
        border.color: "blue"
        border.width: 2
        visible: false
        transform: Scale {
            xScale: 1
            yScale: 1
        }
    }
    function createSelectionBox(item) {
        if (item.parent === canvas) {
            selectionBox.x = item.x - 5;
            selectionBox.y = item.y - 5;
            selectionBox.width = item.width + 10;
            selectionBox.height = item.height + 10;
            selectionBox.visible = true;
            canvas.setChildIndex(selectionBox, canvas.children.length - 1);
            return selectionBox;
        }
    }
    function removeSelectionBox(item) {
        if (selectionBox.parent === canvas) {
            selectionBox.visible = false;
        }
    }
}

在这个修改后的代码中，我添加了一个transform属性到Canvas元素中，用于控制Canvas的缩放比例。在选择框创建时，将缩放比例应用到选择框的transform属性中。同时，我也将选择框的scaleX和scaleY属性修改为transform的xScale和yScale属性，这样就可以正确的使用缩放比例了。