Add Blocks to Control the Buttons - INTRO TO APP INVENTOR - AGTECH

1. Click "Appear" in the "Blocks" section
2. Drag and drop “when Appear.click do” into the viewer
3. Click Image1 in the "Blocks" section
4. Drag “set Image1.visible to” into the viewer and drop it inside the “when Appear.click do” block
5. Click "Logic" in the "Blocks" section
6. Drag “true” into the viewer and drop it at the end of “set Image1.visible to”
7. Repeat steps 3 – 6 for the "Grow", "Shrink", and "Disappear" buttons
8. Repeat steps 3 – 6 for the Appear button, but for step 6 use the “false” block
9. Right click on the “when Appear.Click do” block and select "Duplicate". This will create an additional set of blocks identical to the ones you just created. We will use this set of blocks to program the "Disappear Button". Drag this block down so that you can see both sets of blocks.
10. In “when Appear.Click do”, click on “Appear” and change it to “Disappear”
11. Next, change all the “true” blocks to “false” and the “false” block to “true”

The code that you have just built says when you press the "Appear" button, the image, and other buttons will become visible and the "Appear" button will not be visible. Likewise, when you press the "Disappear" button, the image and grow, shrink, and disappear buttons will not be visible and only the "Visible" button will become visible.

At the Thinkabit Lab, we walk students slowly through each added code, especially at the beginning. Once they know where to find different blocks, we move faster. If you have time and want to give students more practice time, have students build the “when Disappear.Click do” block by going step by step rather than duplicating the block and modifying it. We have noticed when students go through the full building of code and then we introduce the shortcut, it is more exciting and valuable

Can’t find one of the blocks of code

1. Watch the video, pausing as needed to see where to find each block of code.
2. Sometimes you have to scroll up or down to find the blocks of code you need.

Found the block of code, but having trouble getting it to the right place

1. Make sure that you are clicking the block of code you want and drag it to the right place before un-clicking.
2. Using a mouse can be helpful when building block code as dragging and dropping using a track pad could be complicated.