Android layout optimization----viewstub, include, merge

1 Stubview

Function: The layout in the Stubview tag is loaded only when it is needed.

Note: The Stubview render load operation can only be performed once; Merge tags are not supported

Examples of Use:

(1) Layout referenced in Viewstub

<?xml version= "1.0" encoding= "Utf-8"? ><linearlayout android:id= "@+id/stublayout" xmlns:android= "http// Schemas.android.com/apk/res/android "android:orientation=" vertical "android:layout_width=" Match_parent "Android:        layout_height= "Match_parent" > <textview android:id= "@+id/sbtv" android:layout_width= "300DP" android:layout_height= "300DP" android:text= "This is sub text view"/></linearlayout>

(2) using viewstub

<viewstub android:id= "@+id/viewstub" android:layout_width= "100DP" android:layout_height= "100DP" Android:lay out= "@layout/sublayout"/>

(3) Rendering loading in Java code

Viewstub stub = (viewstub) Findviewbyid (r.id.viewstub); Stub.inflate (); TextView STUBTV = (TextView) Layout.findviewbyid (R.ID.SBTV); Stubtv.settext ("Hello stub! ");

2 Include tags

Function: Replaces the referenced layout with the position of the label in the current layout;

Note: The referenced layout is non-merge, and the ID property of the Inlude is overwritten with the ID of the top layout of the referencing layouts;

Example 1 Reference layout non-merge

(1) Reference layout

<?xml version= "1.0" encoding= "Utf-8"? ><linearlayout xmlns:android= "http://schemas.android.com/apk/res/ Android "android:id=" @+id/sharedlayout2 "android:layout_width=" 200DP "android:layout_height=" 200DP "Android:ba        Ckground= "@android: Color/black" > <textview android:id= "@+id/mytv" android:layout_width= "100DP" android:layout_height= "100DP" android:background= "@android: Color/holo_blue_light" android:text= "at this time a common layout "/></linearlayout>

(2) using the Include tag

<include android:id= "@+id/include1" <!--the ID overrides linearlayout id;--> layout= "@layout/my" in the layout (1) android:layou T_width= "50DP" android:layout_height= "50DP" ></include>

(3) using in Java

LinearLayout sharedlayout = (linearlayout) Findviewbyid (R.ID.INCLUDE1); TextView TV = (TextView) Sharedlayout.findviewbyid (R.ID.MYTV); Tv.settext ("Hello Include1");

Example 2 referencing the merge layout

(1) Reference layout

<merge xmlns:android= "Http://schemas.android.com/apk/res/android" >    < Linearlayout        android:id= "@+id/mergetlayout"          android:layout_width= "Wrap_content"          android:layout_height= "Wrap_content" >        <textview             android:id= "@+id/mergetv1"              android:layout_width= "40DP"              android:layout_height= "40DP"              android:background= "@android: Color/holo_blue_bright"              android:text= "Merge text1"  />       &nbSp; <textview            android:id= "@+id/ MERGETV2 "            android:layout_width=" 40DP "             android:layout_height= "40DP"              android:background= "@android: Color/darker_ Gray "            android:text=" Merge text2 "  />    </LinearLayout></merge>

(2) Include tag: the merge layout does not have an id attribute, so the id here actually doesn't make sense

<include android:id= "@+id/include2" layout= "@layout/mymerge" ></include>

(3) using in Java

LinearLayout layout = (linearlayout) Findviewbyid (R.ID.INCLUDE2);//Cannot get through this code (1) In the LinearLayout, the layout here is Nulltextview mTV1 = (TextView) Findviewbyid (R.ID.MERGETV1); Mtv1.settext ("Hello merge TV1 "); TextView MTV2 = (TextView) Findviewbyid (R.ID.MERGETV2); Mtv2.settext ("Hello merge tv2");

3 Merge Tab

The merge label is equivalent to a simple collection of controls, and is laid out after being put into other layouts, based on the container layout associated with each control.

Note: The merge tag does not have an id attribute

Examples of Use:

(1) Merge layout

<merge xmlns:android= "Http://schemas.android.com/apk/res/android" >    < Textview        android:id= "@+id/mergetv1"          android:layout_width= "40DP"         android: layout_height= "40DP"         android:background= "@android: Color/holo_ Blue_bright "        android:text=" Merge text1 " />     <textview        android:id= "@+id/mergetv2"          android:layout_width= "40DP"          android:layout_height= "40DP"         android:background= "@ Android:color/darker_gray "        android:text=" Merge text2 "  /></merge>

At this time the layout is two TextView overlap and MERGETV2 is in the upper layer;

(2) Merge label use

<include android:id= "@+id/include2" layout= "@layout/mymerge" ></include>

(3) Since the include tag is in a vertical linearlayout, the merge layout appears as follows:

Merge Text 1

Merge Text 2

(4) using in Java

TextView mTV1 = (TextView) Findviewbyid (R.ID.MERGETV1); Mtv1.settext ("Hello merge tv1"); TextView MTV2 = (TextView) Findviewbyid (R.ID.MERGETV2); Mtv2.settext ("Hello merge tv2");

This article is from the "Wauoen" blog, make sure to keep this source http://7183397.blog.51cto.com/7173397/1847175

Android layout optimization----viewstub, include, merge