If the layout_width attribute of any control is set to match_parent, it takes up all the available space of the container, hiding the rest of the controls behind it. We also need to set the layout_width attribute of the three controls to wrap_content otherwise, we will be able to see only the first Button control, the one with the Apple ID. To see the controls appear horizontally, set the orientation attribute of the LinearLayout to horizontal. Three Button controls arranged vertically in LinearLayout We see the output shown in Figure 3.1.įigure 3.1. Finally, the width of the three controls is set to match_parent, so that the width of the three controls expands to fill up the available space of the LinearLayout container. The height of the three controls is set to wrap_content, which is enough to accommodate the text. The IDs and text assigned to the three Button controls are Apple, Mango, and Banana, respectively. Three Button controls are added to the layout, which appear one below the other. The height and width of the layout are set to expand to fill up all the available space of the enclosing container, that is, the device screen. The orientation of LinearLayout is set to vertical, declaring that we want to arrange its child elements vertically, one below the other. The activity_linear_layout_app.xml File on Adding Three Button Controls Modify the activity_linear_layout_app.xml to appear as shown in Listing 3.2. Let’s apply the LinearLayout and add three Button controls to the layout. Default Code in the Layout File activity_linear_layout_app.xml The original default content of the layout file activity_linear_layout_app.xml appears as shown in Listing 3.1. Create a new Android Project called LinearLayoutApp. Let’s see how the controls are laid out in the LinearLayout layout using an example. To set the padding at runtime, we can call the setPadding() method. When assigned to the control’s height or width, this attribute forces the size of the control to expand to fill up all the available space of the enclosing container. By providing the value as match_parent.For example, when this value is applied to the width of the TextView, it expands so that its complete text is visible. When assigned to the control’s height or width, this attribute resizes the control to expand to fit its contents. By providing the value as wrap_content.For example, the android:layout_width="20px" attribute sets the width of the control to 20 pixels. By supplying specific dimension values for the control in terms of px (pixels), dip/dp (device independent pixels), sp (scaled pixels), pts (points), in (inches), and mm (millimeters).We can specify the values for the height and width attributes in the following three ways: To specify a certain height and width to the control, we use the android:layout_width and android:layout_height attributes. The default height and width of a control are decided on the basis of the text or content that is displayed through it. That is, by supplying the values HORIZONTAL or VERTICAL to the setOrientation() method, we can arrange the children of the LinearLayout in row or column format, respectively. The orientation can be modified at runtime through the setOrientation() method. Similarly, if the value of the android:orientation attribute is set to horizontal, the controls in the linear layout are arranged in a row format, side by side. If the value of the android:orientation attribute is set to vertical, the children in the linear layout are arranged in a column layout, one below the other. The valid values for this attribute are horizontal and vertical. The orientation attribute is used to arrange its children either in horizontal or vertical order. android:layout_gravity-Used for aligning the control within the container.android:gravity-Used for aligning content within a control.android:layout_weight-Used for shrinking or expanding the size of the control to consume the extra space relative to the other controls in the container. android:padding-Used for increasing the whitespace between the boundaries of the control and its actual content.android:layout_height-Used for defining the height of a control.android:layout_width-Used for defining the width of a control.android:orientation-Used for arranging the controls in the container in horizontal or vertical order.To arrange controls within a linear layout, the following attributes are used: The LinearLayout is the most basic layout, and it arranges its elements sequentially, either horizontally or vertically.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |