Author: Developer Skill Sprints

Introduction to “SaveState”

• Persist form & app state between sessions
• On mobile devices, background apps may be terminated for memory
• Default saves state to transient / temporary storage
• Also option to save to persistent storage

TFormSaveState

• FireMonkey TForm and TForm3D
  • SaveState: TFormSaveState property
  • OnSaveState: TNotifyEvent event
• TFormSaveState.Stream: TMemoryStream
  • Stream to load and save state from
• TFormSaveState.StoragePath: String
  • Location persisted too (default is temporary path)
• TFormSaveState.Name: String
  • Customize persistence file name (allows for multiple files)

Platform Behaviors for SaveState 

• Android
  • Transient is stored in the native activity
  • Transient state lost if app terminated manually
  • Test with “Developer Options” → “Don’t keep activities”
• iOS, Windows, OS X
  • Still persisted when app manually terminated
• Windows & OS X
  • Default location is shared temp folder

More information

• Working with FireMonkey Save State
• OnSaveSate event
• TFormSaveState
• Daniele Spinetti’s SaveState Helper

Samples

• https://github.com/jimmckeeth/SaveStateSamples/

Replays

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