برمجة التطبيقات باستخدام MIT App Inventor - كتاب هندسة البرمجيات - الصف 12 - الفصل 1 - المملكة العربية السعودية

وزارة التعليم Ministry of Education 167 2025 - 1447 --- SECTION: شكل 3.40 --- شكل 3.40: فتح الصفحة المناسبة من التحديد ListPicker (قائمة الخيارات) --- VISUAL CONTEXT --- **DIAGRAM**: شكل 3.40: فتح الصفحة المناسبة من التحديد ListPicker (قائمة الخيارات) Description: A multi-part diagram illustrating conditional screen navigation logic in MIT App Inventor. It shows the App Inventor development environment, specific programming blocks, and the flow of logic for selecting a screen based on user input from a ListPicker. Part 1: Top-left shows the MIT App Inventor interface with 'Blocks' and 'Viewer' tabs. The 'Blocks' section lists 'Built-in' categories: Control, Logic, Math, Text, Lists, Dictionaries, Colors. The 'Viewer' section (indicated by '3') displays three generic blocks: an empty string block (''), a 'join' block, and a 'length' block. Part 2: A code block snippet on the left demonstrates an 'AfterPicking' event for 'riyadh_list'. It sets a 'global selection' variable to the 'riyadh_list Selection'. An 'if' condition checks if 'get global selection' is equal to 'Al Masmak' (English) or 'المصمك' (Arabic), using an 'or' operator. The 'then' part of this conditional block is shown as a placeholder, pointing to the next section. Part 3: A section labeled 'Viewer' (indicated by '4') shows several generic blocks: 'then', 'else', 'do', 'result', 'evaluate but ignore result', 'open another screen screenName AlMasmak', 'open another screen with start value screenName AlMasmak startValue', and 'get start value'. These blocks represent actions that can be placed within the 'then' or 'else' branches of a conditional statement. Part 4: A final code block snippet at the bottom combines the logic. It shows the 'when riyadh_list AfterPicking' event, setting 'global selection'. The 'if' condition is implied to be the same as in Part 2. The 'then' branch now contains the action: 'open another screen with start value screenName AlMasmak startValue get start value'. This illustrates navigating to the 'AlMasmak' screen and passing the 'start value' obtained from the ListPicker selection. Table Structure: Headers: N/A Key Values: MIT APP INVENTOR, Projects, Connect, B, Visit_SA_App, Cities, Add Screen..., Remov, Blocks, Viewer, Built-in, Control, Logic, Math, Text, Lists, Dictionaries, Colors, 3, "", join, length, when riyadh_list AfterPicking, do set global selection to riyadh_list Selection, if, get global selection = "Al Masmak", or, get global selection = "المصمك", then, else, result, evaluate but ignore result, open another screen screenName AlMasmak, open another screen with start value screenName AlMasmak startValue, get start value, 4 Context: This diagram illustrates how to implement conditional logic in MIT App Inventor to control screen navigation. Specifically, it shows how to check a user's selection from a ListPicker (riyadh_list) for specific text values ('Al Masmak' or 'المصمك') and then open a new screen ('AlMasmak') while potentially passing data (startValue). This is a fundamental concept in building interactive mobile applications.