鸿蒙单一方向布局实现音乐播放UI-鸿蒙设置音乐播放

本小节我们将使用DirectionalLayout（单一方向排列布局，我们也可以将其称为线性布局）来实现下面UI图的示例。

UI图拆解

一般我们从UI工程师手里拿到UI界面设计图后，上面有很多尺寸标记等属性。在我们学习了所有布局和组件后，我们完全可以使用一个或者多个布局和组件组合在一起，实现复杂的界面效果。

上面我自己手动拖拽了一个音乐播放界面，没有标注各个属性值，仅用于学习DirectionalLayout布局的使用，不要在意它的美观。

首先我们拿到后，根据上面的标注信息以及组件功能要点等一系列参数，将整个UI界面图根据布局划分多个模块进行父布局占位，然后再根据划分的布局来编写具体的子组件信息。

我根据用户的交互性将整个页面以上下结构划分为两部分，上部分为展示型、下部分为控件型。在底部控件区域，是一系列操作按钮，它们在一个布局中，居中排列。

在上部分的展示区域，我又根据控件类型将区域以左右结构划分为两个部分，左区域显示歌曲作者头像，右侧区域显示歌曲信息。

在右侧歌曲信息区域又划分为上下两个区域，上区域用于展示歌曲名称及作词作曲主唱信息，下区域显示歌词内容。

布局占位

在上面我们已经通过不同的功能，不同的特性将整个UI图拆解成多个部分，现在我们将使用DirectionalLayout布局来进行具体布局占位。

① 首先，我们将整个布局根据权重分为上下两个区域，上区域占4份，下区域占1份。

<?xml version="1.0" encoding="utf-8"?> 
<DirectionalLayout xmlns:ohos="http://schemas.huawei.com/res/ohos" 
                   ohos:width="match_parent" 
                   ohos:height="match_parent" 
                   ohos:background_element="#5c6d71" 
                   ohos:orientation="vertical"> 
    <DirectionalLayout 
            ohos:id="$+id:topLayout" 
            ohos:width="match_parent" 
            ohos:height="0vp" 
            ohos:weight="4"> 
        <Text 
            ohos:width="match_parent" 
            ohos:height="match_parent" 
            ohos:text="上"/> 
    </DirectionalLayout> 
 
    <DirectionalLayout 
            ohos:id="$+id:centerLayout" 
            ohos:width="match_parent" 
            ohos:height="0vp" 
            ohos:background_element="#009688" 
            ohos:weight="1"> 
        <Text 
                ohos:width="match_parent" 
                ohos:height="match_parent" 
                ohos:text="下"/> 
    </DirectionalLayout> 
</DirectionalLayout>

② 接下来我们来进行上区域的左右占位。

<?xml version="1.0" encoding="utf-8"?> 
<DirectionalLayout xmlns:ohos="http://schemas.huawei.com/res/ohos" 
                   ohos:width="match_parent" 
                   ohos:height="match_parent" 
                   ohos:background_element="#5c6d71" 
                   ohos:orientation="vertical"> 
    <DirectionalLayout 
            ohos:id="$+id:topLayout" 
            ohos:width="match_parent" 
            ohos:height="0vp" 
            ohos:weight="4" 
            ohos:orientation="horizontal"> 
        <DirectionalLayout 
                ohos:id="$+id:leftLayout" 
                ohos:width="0vp" 
                ohos:height="match_parent" 
                ohos:weight="1"> 
            <Text 
                    ohos:width="match_parent" 
                    ohos:height="match_parent" 
                    ohos:background_element="#0097A7" 
                    ohos:text="左"/> 
        </DirectionalLayout> 
        <DirectionalLayout 
                ohos:id="$+id:rightLayout" 
                ohos:width="0vp" 
                ohos:height="match_parent" 
                ohos:weight="1"> 
            <Text 
                    ohos:width="match_parent" 
                    ohos:height="match_parent" 
                    ohos:background_element="#03A9F4" 
                    ohos:text="右"/> 
        </DirectionalLayout> 
    </DirectionalLayout> 
 
    <DirectionalLayout 
            ohos:id="$+id:centerLayout" 
            ohos:width="match_parent" 
            ohos:height="0vp" 
            ohos:background_element="#009688" 
            ohos:weight="1"> 
        <Text 
                ohos:width="match_parent" 
                ohos:height="match_parent" 
                ohos:text="下"/> 
    </DirectionalLayout> 
</DirectionalLayout>

③ 上区域的左右布局占位我们已经完成，接下来就是上区域的右侧歌词区域占位，是上下区域占位。

<?xml version="1.0" encoding="utf-8"?> 
<DirectionalLayout xmlns:ohos="http://schemas.huawei.com/res/ohos" 
                   ohos:width="match_parent" 
                   ohos:height="match_parent" 
                   ohos:background_element="#5c6d71" 
                   ohos:orientation="vertical"> 
    <DirectionalLayout 
            ohos:id="$+id:topLayout" 
            ohos:width="match_parent" 
            ohos:height="0vp" 
            ohos:weight="4" 
            ohos:orientation="horizontal"> 
        <DirectionalLayout 
                ohos:id="$+id:leftLayout" 
                ohos:width="0vp" 
                ohos:height="match_parent" 
                ohos:weight="1"> 
            <Text 
                    ohos:width="match_parent" 
                    ohos:height="match_parent" 
                    ohos:background_element="#0097A7" 
                    ohos:text="左"/> 
        </DirectionalLayout> 
        <DirectionalLayout 
                ohos:id="$+id:rightLayout" 
                ohos:width="0vp" 
                ohos:height="match_parent" 
                ohos:weight="1" 
                ohos:orientation="vertical"> 
            <DirectionalLayout 
                    ohos:id="$+id:rightTopLayout" 
                    ohos:width="match_parent" 
                    ohos:height="0vp" 
                    ohos:weight="1"> 
                <Text 
                        ohos:width="match_parent" 
                        ohos:height="match_parent" 
                        ohos:background_element="#00796B" 
                        ohos:text="上"/> 
            </DirectionalLayout> 
            <DirectionalLayout 
                    ohos:id="$+id:rightBottomLayout" 
                    ohos:width="match_parent" 
                    ohos:height="0vp" 
                    ohos:weight="4"> 
                <Text 
                        ohos:width="match_parent" 
                        ohos:height="match_parent" 
                        ohos:background_element="#00BCD4" 
                        ohos:text="下"/> 
            </DirectionalLayout> 
        </DirectionalLayout> 
    </DirectionalLayout> 
 
    <DirectionalLayout 
            ohos:id="$+id:centerLayout" 
            ohos:width="match_parent" 
            ohos:height="0vp" 
            ohos:background_element="#009688" 
            ohos:weight="1"> 
        <Text 
                ohos:width="match_parent" 
                ohos:height="match_parent" 
                ohos:text="下"/> 
    </DirectionalLayout> 
</DirectionalLayout>

以上便是我们将拆解的UI图进行代码布局占位，接下来我们将根据各个区域的实际显示的控件进行完善界面。

定义组件实现UI图

我们先从上下左右的顺序开始编写组件，我们可以看到原图中左侧是一个圆形的图片，用于展示歌曲作者头像。用于显示图像的组件是Image，会在后续的章节中详细讲解。之前我们是使用DirectionalLayout和Text进行占位时，为了明显期间我们代码写的比较啰嗦，在实际的业务中，我们尽可能使用最优写法。

<DirectionalLayout 
          ohos:id="$+id:topLayout" 
          ohos:width="match_parent" 
          ohos:height="0vp" 
          ohos:weight="4" 
          ohos:orientation="horizontal"> 
      <Image 
              ohos:id="$+id:leftLayout" 
              ohos:width="0vp" 
              ohos:height="match_parent" 
              ohos:weight="1" 
              ohos:image_src="$media:changpian"></Image> 
      <DirectionalLayout 
              ohos:id="$+id:rightLayout" 
              ohos:width="0vp" 
              ohos:height="match_parent" 
              ohos:weight="1" 
              ohos:orientation="vertical"> 
          <DirectionalLayout 
                  ohos:id="$+id:rightTopLayout" 
                  ohos:width="match_parent" 
                  ohos:height="0vp" 
                  ohos:weight="1"> 
              <Text 
                      ohos:width="match_parent" 
                      ohos:height="match_parent" 
                      ohos:background_element="#00796B" 
                      ohos:text="上"/> 
          </DirectionalLayout> 
          <DirectionalLayout 
                  ohos:id="$+id:rightBottomLayout" 
                  ohos:width="match_parent" 
                  ohos:height="0vp" 
                  ohos:weight="4"> 
              <Text 
                      ohos:width="match_parent" 
                      ohos:height="match_parent" 
                      ohos:background_element="#00BCD4" 
                      ohos:text="下"/> 
          </DirectionalLayout> 
      </DirectionalLayout> 
  </DirectionalLayout>

讨论

为什么高度已经设置成match_parent，图片还是显示一半呢?是必须为114px才行吗?欢迎讨论!!!

接下来我们将实现右侧的歌词信息布局中的组件。

上布局区域我们把组件都给填充好了，接下来我们将填充下布局区域的组件。在上边文字显示我们目前是以静态方式给定的，所以创建了多个Text组件。

<DirectionalLayout 
           ohos:id="$+id:centerLayout" 
           ohos:width="match_parent" 
           ohos:height="0vp" 
           ohos:weight="1" 
           ohos:alignment="center" 
           ohos:left_margin="200vp" 
           ohos:right_margin="200vp" 
           ohos:orientation="horizontal"> 
       <Image 
               ohos:width="match_content" 
               ohos:height="match_content" 
               ohos:weight="1" 
               ohos:image_src="$media:pinghengqi"/> 
       <Image 
               ohos:width="match_content" 
               ohos:height="match_content" 
               ohos:weight="1" 
               ohos:image_src="$media:kuaitui"/> 
       <Image 
               ohos:width="match_content" 
               ohos:height="match_content" 
               ohos:weight="1" 
               ohos:image_src="$media:bofang"/> 
       <Image 
               ohos:width="match_content" 
               ohos:height="match_content" 
               ohos:weight="1" 
               ohos:image_src="$media:kuaijin"/> 
       <Image 
               ohos:width="match_content" 
               ohos:height="match_content" 
               ohos:weight="1" 
               ohos:image_src="$media:shengyin"/> 
       <Image 
               ohos:width="match_content" 
               ohos:height="match_content" 
               ohos:weight="1" 
               ohos:image_src="$media:liebiao"/> 
   </DirectionalLayout>

我们启动TV模拟器，运行查看是否和我们刚开始的UI图相似(一些尺寸上的差异暂时忽略不计)。

为何图片显示一半?

我们在media中存入的图片应该在32-bit color以下，才能全部渲染。

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https://harmonyos.51cto.com/#zz