HarmonyOS三方件開發指南(13)-SwipeLayout側滑刪除

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目錄：
1. SwipeLayout組件功能介紹
 2. SwipeLayout使用方法
 3. SwipeLayout開發實現
 4.《HarmonyOS三方件開發指南》系列文章合集git

1. SwipeLayout組件功能介紹
1.1.功能介紹：
SwipeLayout組件是一個側滑刪除組件。github

1.2. 模擬器上運行效果：
app

2. SwipeLayout使用方法
2.1. 新建工程，增長組件Har包依賴
在應用模塊中添加HAR，只須要將SwipeLayout.har複製到entry\libs目錄下便可（因爲build.gradle中已經依賴的libs目錄下的*.har，所以不須要再作修改）。函數

2.2. 修改主頁面的佈局文件
修改主頁面的佈局文件ability_main.xml，將自定義的SwipeLayout添加到xml中，將初始狀態下展現的視圖添加到SwipeLayout做爲index爲0的子視圖：佈局

<?xml version="1.0" encoding="utf-8"?>
<DirectionalLayout
    xmlns:ohos="http://schemas.huawei.com/res/ohos"
    ohos:id="$+id:total1"
    ohos:height="match_parent"
    ohos:width="match_parent"
    ohos:background_element="gray"
    ohos:orientation="vertical">
    <com.isoftstone.swipelayout.SwipeLayout
        ohos:id="$+id:sample2"
        ohos:height="80vp"
        ohos:width="match_parent"
        ohos:orientation="horizontal">
        <Text
            ohos:id="$+id:bottom_layout1"
            ohos:height="match_parent"
            ohos:width="match_parent"
            ohos:background_element="white"
            ohos:multiple_lines="true"
            ohos:padding="10"
            ohos:text="要有最樸素的生活和最遙遠的夢想，即便明每天寒地凍，山高水遠，路遠馬亡。"
            ohos:text_alignment="left"
            ohos:text_size="14fp"
            ohos:visibility="visible">
        </Text>
        <DirectionalLayout
            ohos:id="$+id:bottom_wrapper1"
            ohos:height="match_parent"
            ohos:width="360px"
            ohos:background_element="#ddff00"
            ohos:orientation="horizontal"
            ohos:visibility="visible">
            <Text
                ohos:id="$+id:Texts1"
                ohos:height="match_parent"
                ohos:width="180px"
                ohos:background_element="#7B1FA2"
                ohos:left_padding="25"
                ohos:right_padding="25"
                ohos:text="收藏"
                ohos:text_alignment="center"
                ohos:text_color="#DC143C"
                ohos:text_size="14fp"
                ohos:visibility="visible"
                />
            <Text
                ohos:id="$+id:texts2"
                ohos:height="match_parent"
                ohos:width="180px"
                ohos:background_element="#C7C7CC"
                ohos:left_padding="25"
                ohos:right_padding="25"
                ohos:text="刪除"
                ohos:text_alignment="center"
                ohos:text_color="#DC143C"
                ohos:text_size="14fp"
                ohos:visibility="visible"
                />
        </DirectionalLayout>
        <Image
            ohos:id="$+id:images3"
            ohos:height="match_parent"
            ohos:width="match_parent"
            ohos:background_element="gray"
            ohos:image_src="$media:star"
            />
        <DirectionalLayout
            ohos:id="$+id:bottom_fronts"
            ohos:height="match_parent"
            ohos:width="match_content"
            ohos:background_element="#ddff00"
            ohos:orientation="horizontal"
            ohos:visibility="visible">
            <Image
                ohos:id="$+id:images1"
                ohos:height="match_parent"
                ohos:width="180px"
                ohos:background_element="green"
                ohos:image_src="$media:star"/>
            <Image
                ohos:id="$+id:images2"
                ohos:height="match_parent"
                ohos:width="180px"
                ohos:background_element="red"
                ohos:image_src="$media:trash"/>
        </DirectionalLayout>
    </com.isoftstone.swipelayout.SwipeLayout>
    <Image
        ohos:id="$+id:images"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:background_element="green"
        ohos:image_src="$media:star"
        ohos:layout_alignment="horizontal_center"
        ohos:top_margin="100vp"/>
</DirectionalLayout>

2.3. 初始化SwipeLayout
在MainAbilitySlince類的onStart函數中，增長以下代碼。post

SwipeLayout swipeLayout = (SwipeLayout) findComponentById(ResourceTable.Id_sample1);
DirectionalLayout right = (DirectionalLayout) findComponentById(ResourceTable.Id_bottom_wrapper);
//初始化
swipeLayout.initializeSwipe();
DirectionalLayout left = (DirectionalLayout) findComponentById(ResourceTable.Id_bottom_front);
Image image3 = (Image) findComponentById(ResourceTable.Id_image3);
//將各個方向拖拽時對應展現的視圖添加到swipeLayout
swipeLayout.addDrag(SwipeLayout.DragEdge.Left, right);
swipeLayout.addDrag(SwipeLayout.DragEdge.Right, left);
swipeLayout.addDrag(SwipeLayout.DragEdge.Bottom, image3);

3. SwipeLayout開發實現
3.1. 新建一個Module
新建一個Module，類型選擇HarmonyOS Library，模塊名爲SwipeLayout，如圖學習

3.2. 新建一個SwipeLayout類
新建一個SwipeLayout類，繼承自PositionLayout類
SwipeLayout的主要流程：gradle

1. 首先經過xml的構造方法，爲SwipeLayout添加拖拽監聽；
2. 將LinkedHashMap<DragEdge, Component> mDragEdges初始化爲空，並肯定主界面的顯示位置；
3. 經過public void addDrag(DragEdge dragEdge, Component child) 方法將可拖拽的方向和對應展現的視圖添加到mDragEdges，並設置其初始的ContentPosition；ui

public void addDrag(DragEdge dragEdge, Component child) {
    mDragEdges.put(dragEdge, child);
    switch (dragEdge) {
        case Left:
            child.setContentPosition(getWidth(), 0);
            break;
        case Right:
            HiLog.info(label, "Log_addDrag" + child.getHeight());
            child.setContentPosition(-child.getWidth(), 0);
            break;
        case Top:
            child.setContentPosition(0, getHeight());
            break;
        case Bottom:
            child.setContentPosition(0, -child.getHeight());
            break;
    }
    child.setVisibility(INVISIBLE);
    addComponent(child, 0);
}

4.在拖拽動做的監聽回調方法中完成對視圖的更新
A.在update回調中設置打開和關閉的邊界以及邊界內的位置刷新url

if (getSurfaceView().getContentPositionY() + dragInfo.yOffset <= 0) {
    close();
} else if (getSurfaceView().getContentPositionY() + dragInfo.yOffset >= getHeight()) {
    open();
} else {
    getSurfaceView().setContentPositionY(getSurfaceView().getContentPositionY() + (float) dragInfo.yOffset);
    getCurrentBottomView().setContentPositionY(getCurrentBottomView().getContentPositionY() + (float) dragInfo.yOffset);
}

B.在end中判斷滑動的距離，若是大於設定的滑動距離則直接將控件展開或者關閉

if (isCloseBeforeDrag && mDragDistanceY < 0) {
    if (Math.abs(mDragDistanceY) >= mWillOpenPercentAfterClose * getBottomViewHeight()) {
        open();
    } else {
        close();
    }
}
if (!isCloseBeforeDrag && mDragDistanceY > 0) {
    if (Math.abs(mDragDistanceY) >= mWillOpenPercentAfterClose * getBottomViewHeight()) {
        close();
    } else {
        open();
    }
}

3.3. 編譯HAR包
利用Gradle能夠將HarmonyOS Library庫模塊構建爲HAR包，構建HAR包的方法以下：

在Gradle構建任務中，雙擊PackageDebugHar或PackageReleaseHar任務，構建Debug類型或Release類型的HAR。

待構建任務完成後，能夠loadingview> bulid > outputs > har目錄中，獲取生成的HAR包。

項目源代碼地址：https://github.com/isoftstone-dev/SwipeBackLayout

歡迎交流：HWIS-HOS@isoftstone.com