为布局添加空白

If you don't need the gap to be exactly 2 lines high, you can add an empty view like this:

    <View
android:layout_width="fill_parent"
android:layout_height="30dp">
</View>

Use Space or View to add a specific amount of space. For 30 vertical density pixels:

<Space
android:layout_width="1dp"
android:layout_height="30dp"/>

If you need a flexible space-filler, use View between items in a LinearLayout:

<View
android:layout_width="1dp"
android:layout_height="match_parent"
android:layout_weight="1"/>

or

<View
android:layout_width="1dp"
android:layout_height="0dp"
android:layout_weight="1"/>

This works for most layouts for API 14 & later, except widgets (use FrameLayout instead).

[Updated 9/2014 to use Space. Hat tip to @Sean]

<View
android:layout_width="fill_parent"
android:layout_height="30dp"
android:background="#80000000">
</View>

Agree with all the answers......also,

    <TextView android:text=""
android:layout_width="match_parent"
android:layout_height="30dp"
android:layout_weight="2" />

should work :) I am just messing with others as TextView is my favourite (waste of memory though!)

try this

in layout.xml :

<TextView
android:id="@+id/xxx"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="@string/empty_spaces" />

in strings.xml :

<string name="empty_spaces">\t\t</string>

it worked for me

An updated Answer: Since API 14, you can use "Space" View, as described in the documentation.

Space is a lightweight View subclass that may be used to create gaps between components in general purpose layouts.

if you want to give the space between layout .this is the way to use space. if you remove margin it will not appear.use of text inside space to appear is not a good approach. hope that helps.

<Space
android:layout_width="match_content"
android:layout_height="wrap_content"
android:layout_margin="2sp" />

I strongly disagree with CaspNZ's approach.

First of all, this invisible view will be measured because it is "fill_parent". Android will try to calculate the right width of it. Instead, a small constant number (1dp) is recommended here.

Secondly, View should be replaced by a simpler class Space, a class dedicated to create empty spaces between UI component for fastest speed.

View if you need change background color , Space if not .

that dosent mean you have to change view background .

<View
android:layout_width="match_parent"
android:layout_height="20dp"
android:background="@color/YOUR_BACKGROUND">
</View>

or Space

<Space
android:layout_width="match_parent"
android:layout_height="20dp"
/>

The previous answers didn't work in my case. However, creating an empty item in the menu does.

<menu xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android">
...
<item />
...
</menu>

there is a better way to do this just use the code below and change according to what you want the size of the blank area

     <Space
android:layout_width="wrap_content"
android:layout_height="32dp"
android:layout_column="0"
android:layout_row="10" />

if you are using with the grid layoout then only use

 android:layout_row="10" />

This can by be achieved by using space or view.

Space is lightweight but not much flexible.

View occupies a rectangular area on the screen and is responsible for drawing and event handling. View is more customizable, you can add background, draw shapes like space.

Implementing Space :

(Eg: Space For 20 vertical and 10 horizontal density pixels)

<Space
android:layout_width="10dp"
android:layout_height="20dp"/>

Implementing View :

(Eg: View For 20 vertical and 10 horizontal density pixels including a background color)

  <View
android:layout_width="10dp"
android:layout_height="20dp"
android:background="@color/bg_color"/>

Space for string formatting using HTML entity:

  for non-breakable whitespace.   for regular space.

Below is the simple way to create blank line with line size. Here we can adjust size of the blank line. Try this one.

           <TextView
android:id="@id/textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="5dp"/>

Just add weightSum tag to linearlayout to 1 and for the corresponding view beneath it give layout_weight as .9 it will create a space between the views. You can experiment with the values to get appropriate value for you.