如何使用RelativeLayout将Textview置于Listview内部居中？

Question

ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(this,R.layout.activity_haltestellen, R.id.tvHaltestellen, HaltestellenListe);
lvH.setAdapter(arrayAdapter);

this is how the stuff is set and .xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<ListView
    android:id="@+id/lvHaltestellen"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true" >
</ListView>

<TextView
    android:id="@+id/tvHaltestellen"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_alignParentRight="true"

    />

I get the StringArray from a database. so how can center the tv inside the listview? realy bad thing

Answer 1

I'm not quite sure what do you want to do, but if you want to center the TextView inside the RelativeLayout then remove

android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"

from TV and try adding something like android:layout_centarInParent="true" , and in the relative layout change match_parent to wrap_contents

Answer 2

Try to add this one: android:layout_centerInParent="true"

<TextView
    android:id="@+id/tvHaltestellen"
    android:layout_centerInParent="true"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

Answer 3

You could anchor the TextView to the top and bottom of the ListView (and optionally left and right too, depending on the desired effect). That will make the TextView equally tall (and optionally wide), so use a center gravity to position the text in the middle.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <ListView
        android:id="@+id/lvHaltestellen"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true" />

    <TextView
        android:id="@+id/tvHaltestellen"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignTop="@+id/lvHaltestellen"
        android:layout_alignBottom="@+id/lvHaltestellen"
        android:layout_alignLeft="@+id/lvHaltestellen"
        android:layout_alignRight="@+id/lvHaltestellen"
        android:gravity="center" />

</RelativeLayout>

If you're planning to add a background colour to the TextView , you'll need to wrap it inside another transparent container (eg a FrameLayout ), to avoid the colour from obscuring what's displayed in the list. Something like:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <ListView
        android:id="@+id/lvHaltestellen"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true" />

    <FrameLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/lvHaltestellen"
        android:layout_alignLeft="@+id/lvHaltestellen"
        android:layout_alignRight="@+id/lvHaltestellen"
        android:layout_alignTop="@+id/lvHaltestellen" >

        <TextView
            android:id="@+id/tvHaltestellen"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:background="@android:color/black" />
    </FrameLayout>

</RelativeLayout>

Alternatively, if you decide to make the ListView fill up the whole height of the RelativeLayout , you don't need to anchor the TextView to the list anymore. As already pointed out by @user1796624, you can then just center the TextView .

As per your earlier comment on someone else's answer:

the textview is shown inside the listview.

I understand what you're trying to say here, but please do realize that the TextView does not sit inside the ListView , but rather floats on top of it.