I just implemented a ListView inside a LinearLayout, but I need to define the height of the LinearLayout (it has to be 50% of the screen height).
<LinearLayout
android:id="@+id/widget34"
android:layout_width="300px"
android:layout_height="235px"
android:orientation="vertical"
android:layout_below="@+id/tv_scanning_for"
android:layout_centerHorizontal="true">
<ListView
android:id="@+id/lv_events"
android:textSize="18sp"
android:cacheColorHint="#00000000"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/tv_scanning_for"
android:layout_centerHorizontal="true">
</ListView>
</LinearLayout>
Is that possible?
I did something similar for a button and an EditText, but doesn't seem to work on Layouts.
This is my Code:
//capture the size of the devices screen
Display display = getWindowManager().getDefaultDisplay();
double width = display.getWidth();
//my EditText will be smaller than full screen (80%)
double doubleSize = (width/5)*4;
int editTextSize = (int) doubleSize;
//define the EditText
userName = (EditText) this.findViewById(R.id.userName);
password = (EditText) this.findViewById(R.id.password);
//set the size
userName.setWidth(editTextSize);
password.setWidth(editTextSize);
Set its layout_height="0dp"*, add a blank View beneath it (or blank ImageView or just a FrameLayout) with a layout_height also equal to 0dp, and set both Views to have a layout_weight="1"
This will stretch each View equally as it fills the screen. Since both have the same weight, each will take 50% of the screen.
*See adamp's comment for why that works and other really helpful tidbits.
This is easy to do in xml. Set your top container to be a LinearLayout and set the orientation attribute as you wish. Then inside of that place two linearlayouts that both have "fill parent" on width and height. Finally, set the weigth attribute of those two linearlayouts to 1.
This is my android:layout_height=50% activity:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<LinearLayout
android:id="@+id/alipay_login"
style="@style/loginType"
android:background="#27b" >
</LinearLayout>
<LinearLayout
android:id="@+id/taobao_login"
style="@style/loginType"
android:background="#ed6d00" >
</LinearLayout>
</LinearLayout>
style:
<style name="loginType">
<item name="android:layout_width">match_parent</item>
<item name="android:layout_height">match_parent</item>
<item name="android:layout_weight">0.5</item>
<item name="android:orientation">vertical</item>
</style>
best way is use
layout_height="0dp" layout_weight="0.5"
for example
<WebView
android:id="@+id/wvHelp"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="0.5" />
<TextView
android:id="@+id/txtTEMP"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="0.5"
android:text="TextView" />
WebView,TextView have 50% of the screen height
You should do something like that:
<LinearLayout
android:id="@+id/widget34"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:layout_below="@+id/tv_scanning_for"
android:layout_centerHorizontal="true">
<ListView
android:id="@+id/lv_events"
android:textSize="18sp"
android:cacheColorHint="#00000000"
android:layout_height="1"
android:layout_width="fill_parent"
android:layout_weight="0dp"
android:layout_below="@+id/tv_scanning_for"
android:layout_centerHorizontal="true"
/>
</LinearLayout>
Also use dp instead px or read about it here.
it's so easy if you want divide your screen two part vertically ( top30% + bottom70%)
<LinearLayout
android:id="@+id/LinearLayoutTop"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="2">
</LinearLayout>
<LinearLayout
android:id="@+id/LinearLayoutBottom"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1">
</LinearLayout>
To make sure the height of a view is 50% of the screen then we can create two sub LinearLayouts in a LinearLayout. Each of the child LinearLayout should have "android:layout_weight" of 0.5 to cover half the screen
the parent LinearLAyout should have "android:orientation" set to vertical
.
.
here is code for your reference.... this code contains two buttons of height half the screen
<LinearLayout
android:orientation="vertical"
android:layout_height="match_parent">
<LinearLayout
android:layout_weight="0.5"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:padding="10dp"
android:layout_weight="0.5"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:text="button1"
android:id="@+id/button1"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentBottom="true"
/>
<Button
android:padding="10dp"
android:layout_weight="0.5"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:text="button2"
android:id="@+id/button2"
android:layout_alignParentTop="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_alignParentBottom="true"
/>
</LinearLayout>
<LinearLayout
android:layout_weight="0.5"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
</LinearLayout>
</LinearLayout>
This kind of worked for me. Though FAB doesn't float independently, but now it isn't getting pushed down.
Observe the weights given inside the LinearLayout
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:id="@+id/andsanddkasd">
<android.support.v7.widget.RecyclerView
android:id="@+id/sharedResourcesRecyclerView"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="4"
/>
<android.support.design.widget.FloatingActionButton
android:id="@+id/fab"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_gravity="bottom|right"
android:src="@android:drawable/ic_input_add"
android:layout_weight="1"/>
</LinearLayout>
Hope this helps :)
To achieve this feat, define a outer linear layout with a weightSum={amount of weight to distribute}.
it defines the maximum weight sum. If unspecified, the sum is computed by adding the layout_weight of all of the children. This can be used for instance to give a single child 50% of the total available space by giving it a layout_weight of 0.5 and setting the weightSum to 1.0.Another example would be set weightSum=2, and if the two children set layout_weight=1 then each would get 50% of the available space.
WeightSum is dependent on the amount of children in the parent layout.
You can use android:weightSum="2" on the parent layout combined with android:layout_height="1" on the child layout.
<LinearLayout
android:layout_height="match_parent"
android:layout_width="wrap_content"
android:weightSum="2"
>
<ImageView
android:layout_height="1"
android:layout_width="wrap_content" />
</LinearLayout>
来源：https://stackoverflow.com/questions/6794141/androidlayout-height-50-of-the-screen-size