[shutter] shutter debugging (debugging fallback function | debug method of viewing variables in debugging | console information)

One 、 Debug fallback function

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In the course of debugging , Often miss debugging at key locations , If you do not enter the key method for debugging ;

Flutter Debugging provides a " Regret " , Frame window , This window records the running status of all key methods , The value recorded by the running status , You can go back to the specified method ;

Above picture 259 Line of code has been executed , Execute now 188 Lines of code , Click on Frames Medium 259 Execution item of line , You can go back and view the values of related variables or expressions when the state is executed ;

Two 、Debug How to view variables in debugging

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Flutter project Debug During debugging , How to view variables :

Place the cursor at the variable position , Click the left mouse button , The variable value floating layer can be displayed below the variable , Variable values are displayed in the floating layer ;

stay Variables In the variables window , The method of the current breakpoint will be listed , Values of all variables of the class where the breakpoint is located ;

stay Watches In the window , Click on the left Plus button " New Watch " ,

Enter variables or expressions in the pop-up dialog box ,

Click enter , You can view the value of this variable ;

3、 ... and 、Debug Console information

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If an error occurs in the program , An error will be reported to the console ;

If you are debugging code with a large amount of data , It is not convenient to perform breakpoint debugging , Such as Bluetooth serial port data , You need to print the log , Also output to the console ;

Four 、 Related resources

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Reference material :

• Flutter Official website : https://flutter.dev/
• Flutter Plug in download address : https://pub.dev/packages
• Flutter Developing documents : https://flutter.cn/docs ( Strongly recommend )
• official GitHub Address : https://github.com/flutter
• Flutter The Chinese community : https://flutter.cn/
• Flutter Practical tutorial : https://flutter.cn/docs/cookbook
• Flutter CodeLab : https://codelabs.flutter-io.cn/
• Dart Chinese document : https://dart.cn/
• Dart Developer website : https://api.dart.dev/
• Flutter Chinese net : https://flutterchina.club/ , http://flutter.axuer.com/docs/
• Flutter Related issues : https://flutterchina.club/faq/ ( It is recommended to watch it at the introductory stage )
• GitHub Upper Flutter Open source examples : https://download.csdn.net/download/han1202012/15989510
• Flutter Practical e-books : https://book.flutterchina.club/chapter1/

Important topics :

• Flutter Animation reference documentation : https://flutterchina.club/animations/

Blog source download :

• GitHub Address : https://github.com/han1202012/flutter_animation ( Keep updating with the progress of the blog , There may not be the source code of this blog )

• Blog source snapshot : https://download.csdn.net/download/han1202012/16245277 ( The source code snapshot of this blog , You can find the source code of this blog )