{"id":914,"date":"2015-09-11T16:47:07","date_gmt":"2015-09-11T23:47:07","guid":{"rendered":"http:\/\/appinventor.pevest.com\/?p=914"},"modified":"2015-09-11T16:47:07","modified_gmt":"2015-09-11T23:47:07","slug":"how-to-use-the-2-button-notifier-dialog-box","status":"publish","type":"post","link":"https:\/\/coldstreams.com\/appinventor\/2015\/09\/11\/how-to-use-the-2-button-notifier-dialog-box\/","title":{"rendered":"How to use the “2 Button” Notifier dialog box"},"content":{"rendered":"

A reader asked, “When using the 2 button Notifier dialog, how do we know which button was pressed?<\/em>”<\/p>\n

The 2 button Notifier dialog alert box displays 3 buttons(!) – the first two have values you specify, such as “Ok” and “Done”, as shown here, and the third is an optional generic “Cancel” button:<\/p>\n

\"Screenshot_2015-09-11-15-07-15\"<\/a><\/p>\n

The\u00a0Notifier<\/em> component block is a procedure call that has no return value – so how can you determine which button was selected?<\/em><\/p>\n

The answer is that the selected button is returned to\u00a0a separate event handler.<\/p>\n

<\/p>\n

Designer View<\/h2>\n

First, let us set up an example program to demonstrate. Here is a Designer view with a button “Demo the 2 button Notifier”, and two text labels, the last of which \u00a0displays the content of the selected button from the Notifier<\/em>:<\/p>\n

\"Notifier2Buttons_Designer\"<\/a><\/p>\n

Drag the Notifier1<\/em>\u00a0component Palette to the work area; it appears beneath the work area as a “non-visible” component.<\/p>\n

Blocks Code<\/h2>\n

The Click<\/em> event handler for the\u00a0btnStartDemo<\/em> button calls the Notifier’s<\/em> ShowChooseDialog<\/em> procedure, where we specify the text for Button 1 and for Button 2.\u00a0That call displays the dialog box on screen.<\/p>\n

After the user pressed a button, the Notifier<\/em> generates an\u00a0AfterChoosing<\/em> event. The parameter choice<\/em> contains the text of the button that was pressed.<\/p>\n

\"Notifier2Buttons_Blocks2\"<\/a><\/p>\n

The AfterChoosing<\/em> event handler copies\u00a0choice<\/em> to the text label\u00a0to show\u00a0which button was selected. The value of choice<\/em> can be compared in an if-then<\/em>\u00a0block to determine how the app should proceed. If\u00a0the “Ok”\u00a0button was pressed, then the status message is set to the color green, otherwise the text\u00a0is set to blue.<\/p>\n

\"Untitled\"<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

A reader asked, “When using the 2 button Notifier dialog, how do we know which button was pressed?” The 2 button Notifier dialog alert box displays 3 buttons(!) – the first two have values you specify, such as “Ok” and “Done”, as shown here, and the third is an optional generic “Cancel” button: The\u00a0Notifier component … Continue reading How to use the “2 Button” Notifier dialog box<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2,5,10],"tags":[19,22,28,82,126,129,136,151,176,181,192],"class_list":["post-914","post","type-post","status-publish","format-standard","hentry","category-android-development","category-components","category-programming-method","tag-android","tag-app-inventor","tag-appinventor","tag-education","tag-method","tag-mit","tag-notifier","tag-programming","tag-software","tag-stem","tag-technique"],"_links":{"self":[{"href":"https:\/\/coldstreams.com\/appinventor\/wp-json\/wp\/v2\/posts\/914","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/coldstreams.com\/appinventor\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/coldstreams.com\/appinventor\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/coldstreams.com\/appinventor\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/coldstreams.com\/appinventor\/wp-json\/wp\/v2\/comments?post=914"}],"version-history":[{"count":0,"href":"https:\/\/coldstreams.com\/appinventor\/wp-json\/wp\/v2\/posts\/914\/revisions"}],"wp:attachment":[{"href":"https:\/\/coldstreams.com\/appinventor\/wp-json\/wp\/v2\/media?parent=914"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/coldstreams.com\/appinventor\/wp-json\/wp\/v2\/categories?post=914"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/coldstreams.com\/appinventor\/wp-json\/wp\/v2\/tags?post=914"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}