DependentLayout布局
今天来认识一下DependentLayout布局以及如何进行简单的运用
DependentLayout是Java UI系统里的一种常见布局。与DirectionalLayout相比，拥有更多的排布方式，每个组件可以指定相对于其他同级元素的位置，或者指定相对于父组件的位置
DependentLayout布局示意图

排列方式
DependentLayout的排列方式是相对于其他同级组件或者父组件的位置进行布局
相对于同级组件的位置布局见下表

right_of参考如下图
right_of 对应的xml ，above、start_of、left_of、right_of，below等参数可分别实现类似的布局

<?xml version="1.0" encoding="utf-8"?>
<DependentLayout
    xmlns:ohos="http://schemas.huawei.com/res/ohos"
    ohos:height="match_parent"
    ohos:width="match_parent">
    <Button
        ohos:id="$+id:button_1"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:left_margin="15vp"
        ohos:top_margin="15vp"
        ohos:bottom_margin="15vp"
        ohos:background_element="$graphic:color_cyan_element"
        ohos:text="Button_1"
        ohos:text_size="20fp"
    />
    <Button
        ohos:id="$+id:button_2"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:right_margin="15vp"
        ohos:left_margin="15vp"
        ohos:top_margin="15vp"
        ohos:bottom_margin="15vp"
        ohos:background_element="$graphic:color_cyan_element"
        ohos:text="Button_2"
        ohos:text_size="20fp"
        ohos:right_of="$id:button_1"
        />
</DependentLayout>

相对于父组件的位置布局见如下表

以上位置布局可以组合，形成处于左上角、左下角、右上角、右下角的布局。

<?xml version="1.0" encoding="utf-8"?>
<DependentLayout
    xmlns:ohos="http://schemas.huawei.com/res/ohos"
    ohos:height="match_parent"
    ohos:width="match_parent">
    <Button
        ohos:id="$+id:button_1"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:background_element="$graphic:color_cyan_element"
        ohos:text="Button_1"
        ohos:text_size="20fp"
        ohos:align_parent_bottom="true"
    />
    <Button
    ohos:id="$+id:button_2"
    ohos:height="match_content"
    ohos:width="match_content"
    ohos:background_element="$graphic:color_cyan_element"
    ohos:text="Button_2"
    ohos:text_size="20fp"
    ohos:center_in_parent="true"
    />
    <Button
        ohos:id="$+id:button_3"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:background_element="$graphic:color_cyan_element"
        ohos:text="Button_3"
        ohos:text_size="20fp"
        ohos:align_parent_end="true"
        ohos:align_parent_bottom="true"
        />

    <Button
        ohos:id="$+id:button_4"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:background_element="$graphic:color_cyan_element"
        ohos:text="Button_4"
        ohos:text_size="20fp"
        ohos:align_parent_end="true"
        />
    <Button
        ohos:id="$+id:button_5"
        ohos:height="match_content"
        ohos:width="match_content"
        ohos:background_element="$graphic:color_cyan_element"
        ohos:text="Button_5"
        ohos:text_size="20fp"
        ohos:align_parent_top="true"
        />
</DependentLayout>

DependentLayout练习

布局文件

<?xml version="1.0" encoding="utf-8"?>
<DependentLayout
    xmlns:ohos="http://schemas.huawei.com/res/ohos"
    ohos:height="match_parent"
    ohos:width="match_parent"
    ohos:background_element="$graphic:color_gray_element">

    <Text
        ohos:id="$+id:text_1"
        ohos:height="match_content"
        ohos:width="match_parent"
        ohos:background_element="$graphic:color_cyan_element"
        ohos:text="Layout "
        ohos:text_size="35fp"
        ohos:top_margin="35vp"
        ohos:left_margin="35vp"
        ohos:right_margin="35vp"
        ohos:text_weight="1000"
        ohos:text_alignment="horizontal_center"
    />
    <Text
        ohos:id="$+id:text_2"
        ohos:width="match_content"
        ohos:height="140vp"
        ohos:text_size="20vp"
        ohos:background_element="$graphic:color_cyan_element"
        ohos:text="Vertical"
        ohos:top_margin="35vp"
        ohos:left_margin="35vp"
        ohos:right_margin="30vp"
        ohos:bottom_margin="35vp"
        ohos:align_parent_left="true"
        ohos:text_alignment="center"
        ohos:multiple_lines="true"
        ohos:below="$id:text_1"
        ohos:text_font="serif"
        />
        <Text
            ohos:id="$+id:text_3"
            ohos:width="match_parent"
            ohos:height="140vp"
            ohos:text_size="30fp"
            ohos:text="StudyLayout"
            ohos:background_element="$graphic:color_cyan_element"
            ohos:top_margin="35vp"
            ohos:right_margin="30vp"
            ohos:bottom_margin="35vp"
            ohos:text_alignment="center"
            ohos:below="$id:text_1"
            ohos:right_of="$id:text_2"
            ohos:text_font="serif"
            />
        <Button
            ohos:id="$+id:button_1"
            ohos:width="100vp"
            ohos:height="match_content"
            ohos:text_size="35fp"
            ohos:background_element="$graphic:color_cyan_element"
            ohos:text="back"
            ohos:right_margin="10vp"
            ohos:bottom_margin="15vp"
            ohos:left_of="$id:button_2"
            ohos:below="$id:text_3"
            ohos:italic="false"
            ohos:text_weight="5"
            ohos:text_font="serif"
            />
        <Button
            ohos:id="$+id:button_2"
            ohos:width="100vp"
            ohos:height="match_content"
            ohos:text_size="35fp"
            ohos:background_element="$graphic:color_cyan_element"
            ohos:text="Next"
            ohos:right_margin="35vp"
            ohos:bottom_margin="15vp"
            ohos:align_parent_end="true"
            ohos:below="$id:text_3"
            ohos:italic="false"
            ohos:text_weight="5"
            ohos:text_font="serif"
            />
</DependentLayout>

color_cyan_element.xml

<?xml version="1.0" encoding="UTF-8" ?>
<shape xmlns:ohos="http://schemas.huawei.com/res/ohos"
       ohos:shape="rectangle">
    <solid
        ohos:color="#ffbbbbbb"/>
</shape>

color_gray_element.xml

<?xml version="1.0" encoding="UTF-8" ?>
<shape xmlns:ohos="http://schemas.huawei.com/res/ohos"
       ohos:shape="rectangle">
<solid
    ohos:color="#878787"/>
</shape>