Realtivelayout of Android UI (relative layout)

Description: Realtivelayout is the most commonly used layout manager in Android Development (more commonly than linearlayout), where sub-components within a layout are always determined by the other subcomponents and the realtivelayout layout itself. The biggest benefit is more freedom and flexibility, you can design a more cool complex interface, but also in the IDE through the direct drag-and-drop interface layout design.
Note: Realtivelayout subcomponents cannot set the Android:layout_gravity property.

There are more attributes to be concerned about in realtivelayout, which can be divided into three categories:

1 android:ignoregravity

Corresponding method: setignoregravity (int)
Description: Sets the subcomponents that are not affected by the gravity property. As with other layouts, realtivelayout can also use the Android:gravity property to set the placement of its subcomponents, but realtivelayout need to implement a more complex layout, So for all components to set a unified placement method is difficult to meet the actual development of some special needs, so there is this zodiac to do special neglect.
Give me a chestnut:

<RelativeLayout    android:gravity="bottom"    android:ignoreGravity="@id/view1"    android:layout_width="fill_parent"    android:layout_height="fill_parent">    <ImageView        android:id="@+id/view1"        android:layout_width="100dp"        android:layout_height="100dp"        android:scaleType="fitXY"        android:src="@drawable/muogu" />    <ImageView        android:layout_width="100dp"        android:layout_height="100dp"        android:scaleType="fitXY"        android:src="@drawable/nailiu16" /></RelativeLayout>

As you can see, because gravity is set to bottom in Realtivelayout, the second imageview is placed at the bottom of the layout, and the ignoregravity set in View1 is still in its own right, starting from the upper left corner.

2 XML attribute can only be set to True, False

Note: This type of attribute is primarily intended to compensate for the regret that the Realtivelayout subcomponent cannot set the Layout_gravity property, and can be assigned to the subassembly directly.

The following is the property sheet for this type of attribute:

property name	feature description
android:layout_center Horiazontal	Controls whether the subassembly is centered horizontally relative to the parent container
android:layout_centervertical	control the subassembly is Center vertically relative to parent container
android:layout_centerinparent	Controls whether the subassembly is centered relative to the parent container
Android:layout_alignparentbottom	controls whether this subassembly is aligned with the bottom of the parent container
android:layout_alignparenttop	Controls whether this subassembly aligns with the top of the parent container
android:layout_alignparentleft	Controls whether this subassembly aligns with the left of the parent container
android:layout_alignparentright	Controls whether the subassembly is aligned to the right end of the parent container
android:layout_alignparentend	Controls whether the subassembly is aligned to the end of the parent container (in most cases with alignparentright an effect)
Android:layout_alignparentstart	Controls whether the subassembly starts aligning with the parent container (in most cases with an effect of alignparentleft)

It is important to note that these zodiac can be used at the same time, but if conflicting attributes (such as Layout_alignparentleft and layout_alignparentright) are used at the same time, there are some more bizarre effects, It is therefore not recommended to use conflicting properties at the same time.

<RelativeLayout    android:layout_width="fill_parent"    android:layout_height="fill_parent">    <ImageView        android:id="@+id/view1"        android:layout_width="100dp"        android:layout_height="100dp"        android:scaleType="fitXY"        android:layout_alignParentLeft="true"        android:layout_alignParentRight="true"        android:layout_centerVertical="true"        android:layout_centerHorizontal="true"        android:src="@drawable/muogu" /></RelativeLayout>

The system will try to adapt to all of the properties, causing the component to be stretched to a strange look.

3 XML attributes that can be set to other UI component IDs only

Description: These zodiac are the core attributes of Realtivelayout, which are the properties that determine the layout of each sub-component.
The following is the property sheet for this type of attribute:

Property name	function Description
Android:layout_torightof	Controls this subassembly on the right side of the ID specified component
Android:layout_toleftof	Controls this subassembly at the left of the ID specified component
Android:layout_above	Controls the sub-component above the ID specified component
Android:layout_below	Controls the sub-component below the ID specified component
Android:layout_aligntop	Controls the top edge of the component with the ID specified in the upper bounds of the component
Android:layout_alignbottom	Controls the bottom boundary of the end component from the ID specified component
Android:layout_alignleft	Controls the left edge of the component with the ID specified component
Android:layout_alignright	Controls the right edge of the component with the ID specified component
Android:layout_alignstart	Controls the starting position of the component aligned with the starting position of the ID specified component (in most cases the same as the Layout_alignleft effect)
Android:layout_alignend	Controls where the end position of the component is aligned with the end position of the specified component of the ID (in most cases the same as the Layout_alignright effect)

You can also use margin or padding to make minor adjustments to the components as follows:

 <RelativeLayout    android:layout_width="fill_parent"    android:layout_height="fill_parent">    <ImageView        android:id="@+id/view1"        android:layout_width="100dp"        android:layout_height="100dp"        android:layout_alignParentEnd="true"        android:src="@drawable/nailiu16"        android:scaleType="fitXY" />    <ImageView        android:id="@+id/view2"        android:layout_width="100dp"        android:layout_height="100dp"        android:src="@drawable/muogu"        android:scaleType="fitXY"        android:layout_alignParentRight="true"        android:layout_below="@+id/view1" />    <ImageView        android:layout_width="100dp"        android:layout_height="100dp"        android:src="@drawable/muogu"        android:scaleType="fitXY"        android:layout_margin="50dp"        android:layout_alignParentRight="true"        android:layout_alignBottom="@+id/view2" /></RelativeLayout>

Attached: Citation statement

"Crazy Android Handout (second edition)" Li Gang "2.2.4 relative layout" Electronic industry Press

Realtivelayout of Android UI (relative layout)