[Solved CODING BEGINNER] How can I show a images from listbox ?

[danzey]

Hello , i have a emergency!
i look for a way to execute a image from a listbox taken randomly.

i tried this:

textbox1.test = random_number ' i managed to generate a random number
picture1.image = listbox1.item(textbox1.text) but it don't work
also
picture1.image = image.location(listbox1.item(textbox1.text)) ' notice important i add all path my pictures are in my.resources.[name of pictures] !
NO result! crash of applications.

somebody could be my savior! help me please! thank you so much for your answer in advance!

[OptionBase1]

Since "executing an image" is a nonsensical goal, step 1 is to explain exactly what you are trying to accomplish.

[danzey]

Since "executing an image" is a nonsensical goal, step 1 is to explain exactly what you are trying to accomplish.

indeed,i would like show a image simply fom a list in a listbox.

[Shaggy Hiker]

My first advice is for you to turn on Option Strict, which can be done in Project|Properties on the Compile tab, or more permanently under the Options.

Option Strict will disallow implicit conversions, which are indirectly at the root of the problem. Of course, if implicit conversions are disallowed, it will mean that you will need to explicitly convert things, which means thinking more about types. Explicit conversions are faster, but you won't see that, so it won't really matter. Still, it will help. For example, anything in a textbox is text. It may look like an integer, but it is a string. Using a string to index a listbox wouldn't work, except that Option Strict Off is allowing an implicit conversion of the string into an integer, but what are you getting back? You're obviously hoping that it will be a picture...eventually, but it probably isn't. So, what IS in that listbox? What are you getting back from it? I'm guessing that what you are getting back is a filename complete with path, but that's just a guess. That would be a string, though, and most likely what you are getting back is an Object that is being implicitly converted to something.

Tell us what is in the listbox, and what error message you are getting. Then, stop using implicit conversions as a crutch, because it isn't helping you any.

[danzey]

[thank you for your help!

first , i try a thing like this: PictureBox1.Image = My.Resources.ResourceManager.GetObject(ListBox1.Items(TextBox6.Text))

My first advice is for you to turn on Option Strict, which can be done in Project|Properties on the Compile tab, or more permanently under the Options.

Option Strict will disallow implicit conversions, which are indirectly at the root of the problem. Of course, if implicit conversions are disallowed, it will mean that you will need to explicitly convert things, which means thinking more about types. Explicit conversions are faster, but you won't see that, so it won't really matter. Still, it will help. For example, anything in a textbox is text. It may look like an integer, but it is a string. Using a string to index a listbox wouldn't work, except that Option Strict Off is allowing an implicit conversion of the string into an integer, but what are you getting back? You're obviously hoping that it will be a picture...eventually, but it probably isn't. So, what IS in that listbox? What are you getting back from it? I'm guessing that what you are getting back is a filename complete with path, but that's just a guess. That would be a string, though, and most likely what you are getting back is an Object that is being implicitly converted to something.

Tell us what is in the listbox, and what error message you are getting. Then, stop using implicit conversions as a crutch, because it isn't helping you any.

i added the names of my pictures. they are in my.resources included with my exe(application).

[Shaggy Hiker]

Just the names of your pictures?

So, what happened when you tried a thing like that? Personally, I've never done anything like what you are doing, so off the top of my head, I don't know how to do this. You are implicitly converting the string from the textbox into an integer. That will either work or crash, depending on what is in the textbox. You are then using that to get something back from a Listbox, which is probably being implicitly converted to something from an Object. That will probably work, because the Object is probably a string, and a string is the proper argument for GetObject. That implicit conversion will probably give you the string you are expecting, and isn't likely to fail. However, if it isn't working, then something is wrong with it. If you are getting an error message, you'd have to tell us what it was. If you aren't getting an error message, then you might put a breakpoint on that line and see what

ListBox1.Items(TextBox6.Text)

returns. Is it what you expect? If so, then what does

My.Resources.ResourceManager.GetObject(ListBox1.Items(TextBox6.Text))

return?

[danzey]

Just the names of your pictures?

So, what happened when you tried a thing like that? Personally, I've never done anything like what you are doing, so off the top of my head, I don't know how to do this. You are implicitly converting the string from the textbox into an integer. That will either work or crash, depending on what is in the textbox. You are then using that to get something back from a Listbox, which is probably being implicitly converted to something from an Object. That will probably work, because the Object is probably a string, and a string is the proper argument for GetObject. That implicit conversion will probably give you the string you are expecting, and isn't likely to fail. However, if it isn't working, then something is wrong with it. If you are getting an error message, you'd have to tell us what it was. If you aren't getting an error message, then you might put a breakpoint on that line and see what

ListBox1.Items(TextBox6.Text)

returns. Is it what you expect? If so, then what does

My.Resources.ResourceManager.GetObject(ListBox1.Items(TextBox6.Text))

return?

if i have no result ,the picture don't show but i have no crash!
i am going to try with My.Resources.ResourceManager.GetObject(ListBox1.Items(TextBox6.Text).ToString)
wait ... wait... it seems to work... i will comfirm with My.Resources.ResourceManager.GetObject(ListBox1.Items(TextBox6.Text))

[Shaggy Hiker]

Well, if it works it works, but there are a couple things you really need to change:

1) Turn Option Strict ON and fix the errors that causes. Implicit conversions aren't just slow, they also can hide some really interesting bugs.
2) Use better names for controls. Leaving those default names will end up biting you badly at some point.
3) If you don't know about debugging, at least as far as breakpoints and examining the code at a breakpoint, it would be the most useful (and one of the simplest) tools you can learn.

[danzey]

Well, if it works it works, but there are a couple things you really need to change:

1) Turn Option Strict ON and fix the errors that causes. Implicit conversions aren't just slow, they also can hide some really interesting bugs.
2) Use better names for controls. Leaving those default names will end up biting you badly at some point.
3) If you don't know about debugging, at least as far as breakpoints and examining the code at a breakpoint, it would be the most useful (and one of the simplest) tools you can learn.

thank you for all! thank you for your advice i will do my best!
i confirm it works! solved now!