Android layout manager and android layout manager

Android layout manager and android layout manager
Content

• Environment
• Project Structure
• Linear Layout
• Table Layout
• Frame Layout
• Relative Layout
• Grid layout
• Absolute Layout

 
I recently wrote my own Andorid APP and encountered the problem of drawing the interface. It was a headache to start the background and see the painting interface, but it seems that I can't do it without studying it ~ At least the Andorid interface is much simpler than the Web interface. Just try the attributes on your own ~

Download Demo Environment

• Windows 2008 R2 64-bit
• Eclipse ADT V22.6.2, Android 4.4.2 (API 19)
• SAMSUNG GT-8618, 3.5 inch screens (7.5x5 cm, same apple size), Android OS 4.1.2

 

Project Structure

Figure 1.1 project structure diagram 1.2 Main Program

 

Linear Layout

The LinearLayout layout will arrange the components in the container one by one. LinearLayout can control the horizontal arrangement of each component (throughAndroid: orentationAttribute control), you can also control the vertical arrangement of each component.

The LinearLayout layout does not contain line breaks. When the components are arranged in the header one by one, the remaining components are not displayed.

Figure 2 linear Layout

 
Note: There are 3 textviews and 15 buttons on the page. The outermost layer isAndroid: orientation = "vertical"Vertical layout. In the vertical layout, the buttons are from 1 ~ 10 adoptAndroid: orientation = "horizontal"Horizontal layout, but only the button 1 ~ 5. The buttons are displayed ~ 15 vertical layout is also adopted andAndroid: gravity = "bottom | center_horizontal"Attribute, that is, the bottom and horizontal center.

Table 1 common XML attributes of LinearLayout

XML attributes	Description
Android: baselineAligned	Set this attributeFalseWill prevent the layout manager from alignment with its child elements
Android: divider	Split between two buttons when setting Layout
Android: gravity	Sets the alignment of components in the layout manager. For exampleTop,Left,Center_verticalYou can also specify a combination of multiple alignment methods, suchLeft | center_vertical, Indicating the center on the left and vertical of the screen
Android: measureWithLargestChild	When the attribute isTrueAll child elements with weight have the minimum size of the Maximum child element.
Android: orientation	Set the arrangement of components in the layout managerHorizontal,VerticalOne
Android: layout_gravity	Specifies the alignment of the child element in LinearLayout.
Android: layout_weight	Specify the weight of the child element in LinearLayout.

 
The method corresponding to the attribute isSet ***It is easy to recognize. The same below.

 

Table Layout

The TableLayout layout manages components in the form of rows and columns. Instead of explicitly declaring the number of rows and columns, it adds TableRow and other components to control the number of rows and columns of the table.

TableLayout inherits LinearLayout, so it is essentially a linear layout manager.

Figure 3-1 table layoutFigure 3-2 table layout

Table 2 common XML attributes of TableLayout

XML attributes	Description
Android: collapseColumns	Set the sequence number of the columns to be hidden. Multiple column numbers are separated by commas (,).
Android: shrinkColumns	Set the number of columns allowed to be shrunk. Multiple column numbers are separated by commas (,).
Android: stretchColumns	Set the sequence numbers of columns that can be stretched. Multiple column numbers are separated by commas (,).

 

Frame Layout

The FrameLayout layout creates a blank area (called a frame) for each component that is added to it. Each child component occupies one frame, which is automatically aligned according to the gravity attribute. The effect of the frame layout is similar to that of the CardLayout of AWT, which overlays components one by one.

Figure 4 frame Layout-neon lights

Table 3 common XML attributes of FrameLayout

XML attributes	Description
Android: foreground	Set the foreground image of the frame layout container
Android: foregroundGravity	Define the gravity attribute for creating foreground images

 

Relative Layout

The position of the Child component in the RelativeLayout layout is always determined by the sibling component and parent container. Therefore, it is called relative layout.

If the position of component A is determined by the position of component B, Android requires that component B be defined before component A be defined.

Figure 5-1 relative LayoutFigure 5-2 relative Layout-plum blossom

Table 4.1 RelativeLayout XML attributes

XML attributes	Description
Android: gravity	Sets the alignment of each sub-component in the layout container.
Android: ignoreGravity	Set which component is not affected by the gravity attribute

To control the layout of child components in the layout container, RelativeLayout provides an internal class: RelativeLayout. LayoutParams, which provides a large number of XML attributes to control the layout of child components in RelativeLayout.

Table 4.2 RelativeLayout. LayoutParams can only be set as a boolean attribute.

XML attributes	Description
Android: layout_centerHorizontal	Determines whether the child widget is horizontally centered in the layout container.
Android: layout_centerVertical	Determines whether the child widget is in the vertical center of the layout container.
Android: layout_centerInParent	Determines whether the child widget is located in the center of the layout container.
Android: layout_alignParentBottom	Determines whether the sub-component is aligned with the bottom of the layout container.
Android: layout_alignParentLeft	Determines whether the child widget is aligned with the left side of the layout container.
Android: layout_alignParentRight	Determines whether the child widget is aligned with the right side of the layout container.
Android: layout_alignParentTop	Determines whether the child widget is aligned with the top of the layout container.

Table 4.3 RelativeLayout. LayoutParams can only be set to attributes of other UI component IDs.

XML attributes	Description
Android: layout_toRightOf	Control the child widget to the right of the given ID widget
Android: layout_toLeftOf	Controls that the child widget is located on the left of the given ID widget.
Android: layout_abve	Control the sub-component to be located above the specified ID component
Android: layout_below	Control the sub-component to be located below the specified ID component
Android: layout_alignTop	Controls the upper boundary alignment of a child widget with a given ID
Android: layout_alignBottom	Controls the sub-component to be located at the bottom boundary alignment of the given ID component.
Android: layout_alignLeft	Controls the left boundary alignment of a child widget with a given ID
Android: layout_alignRight	Controls the right boundary alignment of a child widget with a given ID

 

Grid layout

GridLayout layout is a new layout manager for Android 4.0. Before that, if you want to achieve the grid effect, the most common choice is to use the LinearLayout layout. Secondly, you can use the TabelLayout layout, but there are all problems. What problems have been solved now, I will not talk about it any more.

The role of GridLayout is similar to the table label of HTML. It divides the entire container into rows x column grids, and each grid can be placed with one component. You can also set how many columns A component spans and how many rows a component spans.

Figure 6 grid layout-calculator

Table 5 GridLayout XML attributes

XML attributes	Description
Android: alignmentMode	Sets the alignment mode used by the layout manager.
Android: columnCount	Set the number of columns in the grid.
Android: columnOrderPreserved	Set whether the Grid container retains column numbers.
Android: rowCount	Set the number of rows in the grid.
Android: rowOrderPreserved	Set whether the Grid container retains row numbers.
Android: usedefamarmargins	Sets whether the layout manager uses the default margins.

 

The absolute layout AbsoluteLayout layout does not provide any layout control, but allows developers to control the component position through the X and Y coordinates themselves. When the AbsoluteLayout layout is used, the layout container no longer manages the positions and sizes of child components-all of which must be controlled by developers themselves.

Figure 7-1 absolute LayoutFigure 7-2 absolute Layout

 
Note: The AbsoluteLayout layout is outdated. Mobile phones running Android applications are often very different, so there may be large differences in screen size and differentiation rate. It is difficult to take into account different screen sizes and resolutions when using absolute layout.

 

Download Demo

What layout manager is available for android?

LinearLayout, TableLayout, RelativeLayout, and FrameLayout also have an unrecommended AbsoluteLayout
LinearLayout is commonly used for beginners. Later, RelativeLayout ~~ will be used for writing interfaces ~~

How to change the default layout of the layout manager in eclipse

Right-click layout, click new, and select android XML file. The default value is Linearlayout.