Android Studio-02【使用Layout Editor建立使用者介面 use the Layout Editor build a UI】

 1.  設置工作區 Set up your workspace

     app → res → layout → activity_main.xml.

     Click Select Design Surface → Select Blueprint

     Click View Options → Select Show All Constraints   

     Click Default Margins → Select 16

     Click Device for Preview → Select your device

 2.  加入文字及按鈕 Add a text box and a button

     Click TextView in the Component Tree panel → Press the Delete key

     Drag Plain Text  

     Drag button  

     Click Select Design Surface → Select Design

 3.  變更文字串內容 Change the UI strings

     app → res → values → strings.xml.

     Click Open editor (opens the Translations Editor) → Click Add Key

• Add Key 1:  
• Key: "edit_message"
• Default Value: "Enter a message"
• Add Key 2:  
• Key: "button_send"
• Default Value: "Send"

     Click activity_main.xml  → Click Attributes window

•  text box:  
• text property: Delete the value
• hint property: Click Pick a Resource. Double-click edit_message

•  button:  
• text property: Delete the value
• hint property: Click Pick a Resource. Double-click button_send

 4.  Run the app on an emulator(AVD). Successfully!