QML Delegate中访问该持有者的方式 附加属性（转载）

http://blog.csdn.net/yuxiaohen/article/details/17226971

用法很奇葩记录一下，实测可以，用于弱化delegate与持有者的依赖

delegate: Component {

            Rectangle {

                id:wrapper

                 parent.width;

                height: 30;

                BorderImage {

                    id:bg_element

//                    source: wrapper.isCurrent

                    anchors.fill:parent;

                    border.left: 5; border.top: 5

                    border.right: 5; border.bottom: 5

                }

                Text {

                    anchors.left: parent.left;

                    anchors.verticalCenter: parent.verticalCenter;

                    anchors.leftMargin: parent.width * 0.6;

                    verticalAlignment: Text.AlignVCenter;

                    font.family: "SimSun";

                    text: people_name;

                }

                MouseArea {

                    anchors.fill: parent;

                    hoverEnabled: true;

                    onEntered: {

                        console.log("enter");

                        bg_element.source = "qrc:/images/images/pointer_hover.png";

                    }

                    onExited: {

                        console.log("exit");

                        bg_element.source = ""

                    }

                    onClicked: {

                        console.log("index",index);

                        wrapper.ListView.view.currentIndex = index;

                        console.log("current index",wrapper.ListView.view.currentIndex);

                        console.log("is current item",wrapper.ListView.isCurrentItem);

                        console.log("model:",wrapper.ListView.view.model);

                        console.log("clicked");

                        bg_element.source = "qrc:/images/images/pointer_clicked.png";

                    }

                }

            }

        }

这里涉及到附加属性和属性的概念,访问附加属性时不需要element实体,感觉有点像使用class的static成员,而属性是需要element实体的.

譬如如上代码,delegate是个component,在Rectangle(也就是id为wrapper)这一作用域,才可直接访问ListView的属性(可能附加属性也是如此,没深究)

要访问的isCurrentItem是ListView的附加属性,则 wrapper.ListView.isCurrentItem 即可

要访问的currentIndex是ListView的属性,则 wrapper.ListView.view.currentIndex 才行