The items can be aligned in two ways:
1.By dragging and dropping / resizing the controls
Refer to the Editing the dialog canvas section for more information about guidelines and aligning.
2.By selecting more than one element and choosing the alignment options
When more than one control is selected, the sidebar shows the alignment options:
Use the buttons to align all selected controls to left / right / top / bottom, or center them vertically / horizontally or both vertically and horizontally.