android - Textview 消失但 listview 可见

Question

我试图在布局中将textview放在listview的顶部，但是textview的内容是不可见的。在设计 View 中有相对布局的空间，但我看不到内容。

这是我的布局 xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<!-- TODO: Update blank fragment layout -->
<RelativeLayout
    android:id = "@+id/relativeLayout1"
    android:layout_width = "wrap_content"
    android:layout_height = "wrap_content"
    android:orientation="horizontal">

    <TextView
        android:layout_width = "0dp"
        android:layout_height = "wrap_content"
        android:layout_weight = "1"
        android:gravity = "center"
        android:padding = "5dp"
        android:text = "@string/product"
        android:textColor = "#ffffff" />

    <TextView
        android:layout_width = "0dp"
        android:layout_height = "wrap_content"
        android:layout_weight = "2"
        android:gravity = "center"
        android:padding = "5dp"
        android:text = "@string/category"
        android:textColor = "#ffffff" />

    <TextView
        android:layout_width = "0dp"
        android:layout_height = "wrap_content"
        android:layout_weight = "1.5"
        android:gravity = "center"
        android:padding = "5dp"
        android:text = "@string/quantity"
        android:textColor = "#ffffff" >
    </TextView>
    <TextView
        android:layout_width = "0dp"
        android:layout_height = "wrap_content"
        android:layout_weight = "1"
        android:gravity = "center"
        android:padding = "5dp"
        android:text = "@string/price"
        android:textColor = "#ffffff" >
    </TextView>
</RelativeLayout>
<ListView
    android:id = "@+id/listview"
    android:layout_width = "match_parent"
    android:layout_height = "fill_parent"
    android:layout_weight = "1"
    android:layout_below="@+id/relativeLayout1"/>
</RelativeLayout>

请指导。 Screenshot

Answer 1

       <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <!-- TODO: Update blank fragment layout -->
    <LinearLayout
        android:id="@+id/relativeLayout1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:orientation="horizontal">

        <TextView
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:gravity="center"
            android:lines="1"
            android:maxLines="1"
            android:padding="5dp"
            android:text="Product"
            android:textColor="#000000" />

        <TextView
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:gravity="center"
            android:lines="1"
            android:maxLines="1"
            android:padding="5dp"
            android:text="Category"
            android:textColor="#000000" />

        <TextView
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:lines="1"
            android:maxLines="1"
            android:gravity="center"
            android:padding="5dp"
            android:text="Quantity"
            android:textColor="#000000" />

        <TextView
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:lines="1"
            android:maxLines="1"
            android:gravity="center"
            android:padding="5dp"
            android:text="Price"
            android:textColor="#000000" />
    </LinearLayout>

    <ListView
        android:id="@+id/listview"
        android:layout_width="match_parent"
        android:layout_height="fill_parent"
        android:layout_below="@+id/relativeLayout1"
        android:padding="5dp" />
</RelativeLayout>

用这个改变你的布局将解决你的问题。当你想用权重管理你的布局时，还有一件事总是使用 LinearLayout，因为 RelativeLayout 不支持权重概念。