Android Layout Secrets

Objective

Write down some of the understanding of the layout today, including the inheritance of the properties of the control, the relationship between the control and the properties of the container, and the use of the properties of the various classes.

Types of properties for controls

In general, when we assign a property to a control, we generally have a type of property, a property that begins with Layout_, a property that does not start with Layout_, and is described below as an example of TextView, as follows

　　

1 <Relativelayout2     Android:layout_width= "Match_parent"3 Android:layout_height= "Match_parent" >4 5     <TextView6         Android:layout_width= "Wrap_content"7 Android:layout_height= "Wrap_content"8 Android:text= "Hello_world" />9         Ten </Relativelayout>

I set three properties Layout_width, Layout_height, and text for TextView, and I can see that the Layout_width and Layout_height properties in these three properties are Layout_ Beginning and text does not start with Layout_.

Attributes that begin with Layout_ are inherited from the container, which in this case is inherited from the relativelayout, and TextView itself does not have this property. The text is a property owned by TextView itself.

To illustrate that the layout property is a container property, I have made the following example, placing the TextView in Relativelayout and LinearLayout, and then setting the Layout_centerinparent property on the TextView, All of this property is selected because this property is relativelayout all and linearlayout not, the experiment code is as follows

　　

1 <Relativelayout2     Android:layout_width= "Wrap_content"3 Android:layout_height= "Wrap_content" >4 5     <TextView6         Android:layout_width= "Wrap_content"7 Android:layout_height= "Wrap_content"8 android:layout_centerinparent= "true"9 Android:text= "Hello_world" />Ten </Relativelayout> One  A <LinearLayout -     Android:layout_width= "Wrap_content" - Android:layout_height= "Wrap_content" > the  -     <TextView -         Android:layout_width= "Wrap_content" - Android:layout_height= "Wrap_content" + android:layout_centerinparent= "true" - Android:text= "Hello world2" /> + </LinearLayout>

As shown above, the editor prompts "Invalid layout param in a linearlayout:layout_centerinparent" as follows

　　

Through this experiment, it can be concluded that the properties at the beginning of layout are not owned by TextView, but rather the properties of the layout in the inherited container, and then, by the same conclusion, the properties of the control can be divided into its own properties and the layout properties in the container. The following is a detailed analysis of subordinates through TextView and various layout containers.

LinearLayout and TextView

This section mainly introduces the properties of the next LinearLayout and TextView, first to look at the properties of TextView, and the property inheritance relationship,

The following properties are owned by the TextView itself

XML Attributes
Attribute Name
Android:autolink
Android:autotext
Android:buffertype
Android:capitalize
Android:cursorvisible
Android:digits
Android:drawablebottom
Android:drawableend
Android:drawableleft
Android:drawablepadding
Android:drawableright
Android:drawablestart
Android:drawabletop
Android:editable
Android:editorextras
Android:ellipsize
Android:ems
Android:fontfamily
Android:freezestext
Android:gravity
Android:height
Android:hint
Android:imeactionid
Android:imeactionlabel
Android:imeoptions
Android:includefontpadding
Android:inputmethod
Android:inputtype
Android:linespacingextra
Android:linespacingmultiplier
Android:lines
Android:linksclickable
Android:marqueerepeatlimit
Android:maxems
Android:maxheight
Android:maxlength
Android:maxlines
Android:maxwidth
Android:minems
Android:minheight
Android:minlines
Android:minwidth
Android:numeric
Android:password
Android:phonenumber
Android:privateimeoptions
Android:scrollhorizontally
Android:selectallonfocus
Android:shadowcolor
Android:shadowdx
Android:shadowdy
Android:shadowradius
Android:singleline
Android:text
Android:textallcaps
Android:textappearance
Android:textcolor
Android:textcolorhighlight
Android:textcolorhint
Android:textcolorlink
Android:textisselectable
Android:textscalex
Android:textsize
Android:textstyle
Android:typeface
Android:width

　　
TextView Inheritance Properties

　　

Inherited XML Attributes

From class Android.view.View

Attribute Name

Android:accessibilityliveregion

Android:alpha

Android:background

Android:clickable

Android:contentdescription

Android:drawingcachequality

Android:duplicateparentstate

Android:fadescrollbars

Android:fadingedgelength

Android:filtertoucheswhenobscured

Android:fitssystemwindows

Android:focusable

Android:focusableintouchmode

Android:hapticfeedbackenabled

Android:id

Android:importantforaccessibility

Android:isscrollcontainer

Android:keepscreenon

Android:layertype

Android:layoutdirection

Android:longclickable

Android:minheight

Android:minwidth

Android:nextfocusdown

Android:nextfocusforward

Android:nextfocusleft

Android:nextfocusright

Android:nextfocusup

Android:onclick

Android:padding

Android:paddingbottom

Android:paddingend

Android:paddingleft

Android:paddingright

Android:paddingstart

Android:paddingtop

Android:requiresfadingedge

Android:rotation

Android:rotationx

Android:rotationy

Android:saveenabled

Android:scalex

Android:scaley

Android:scrollx

Android:scrolly

Android:scrollbaralwaysdrawhorizontaltrack

Android:scrollbaralwaysdrawverticaltrack

Android:scrollbardefaultdelaybeforefade

Android:scrollbarfadeduration

Android:scrollbarsize

Android:scrollbarstyle

Android:scrollbarthumbhorizontal

Android:scrollbarthumbvertical

Android:scrollbartrackhorizontal

Android:scrollbartrackvertical

Android:scrollbars

Android:soundeffectsenabled

Android:tag

Android:textalignment

Android:textdirection

Android:transformpivotx

Android:transformpivoty

Android:translationx

Android:translationy

Android:visibility

That is to say, these two parts add up is TextView all the properties, however, when we edit the code in the XML editor, we will find that in addition to the above attributes, there are many attributes that begin with layout can be set, these are the container properties, the following linearlayout as an example, The experimental scenario is as follows

　　

1 <LinearLayout2     Android:layout_width= "Wrap_content"3 Android:layout_height= "Wrap_content" >4 5     <TextView6         Android:layout_width= "Wrap_content"7 Android:layout_height= "Wrap_content"9 Android:text= "Hello world2" />Ten </LinearLayout>

Let's take a look at the layout properties of LinearLayout, which is represented by the Linearlayout.layoutparams class.

As you can see from the Help document, its own properties are the following:

　　

XML Attributes
Attribute Name
Android:layout_gravity
Android:layout_weight

There are two types of attributes inherited, Android.view.ViewGroup.MarginLayoutParams

　　

Attribute Name

Android:layout_marginbottom

Android:layout_marginend

Android:layout_marginleft

Android:layout_marginright

Android:layout_marginstart

Android:layout_margintop

and Android.view.ViewGroup.LayoutParams

Attribute Name	Related Method	Description
Android:layout_height		Specifies the basic height of the view.
Android:layout_width		Specifies the basic width of the view.

All of the above properties are the layout properties provided by the layout control

Therefore, the properties that TextView can set are the properties of itself and the layout properties above.

Postscript

Above, we analyze the use of the properties of the layout in Android through the combination of linearlayout and textview, so that we can understand the origin of the control properties, so that the layout of the interface will be more arbitrary.

The same reason, can analyze relativelayout, tablelayout and so on.

　　

Original address: http://www.cnblogs.com/luoaz/p/3947100.html

　　

Android Layout Secrets