I tried to make my own small calculator, but I don't want to make all the business logic by myself. So I tried to use the javax.script since I heard that the javax.script needs a real JVM and is a JavaScriptParser. Then, I searched for other libraries with the functions I needed and found the project "exp4j". First, I made a small normal Java Project with JDK 1.7, and yes, it works with the source code:
public static void main(String[] args) throws UnknownFunctionException, UnparsableExpressionException {
ExpressionBuilder builder=new ExpressionBuilder("34*2");
Calculable calc=builder.build();
System.out.println(calc.calculate());
}
Then, I tried the same code in my model (MVC Pattern) of my calculator:
public void berechnen() throws UnknownFunctionException, UnparsableExpressionException {
ExpressionBuilder builder=new ExpressionBuilder("34*2");
Calculable calc=builder.build();
setErgebnis(calc.calculate());
}
But every time I got the same exception:
"AndroidRuntime(630): java.lang.VerifyError",
after I started the app. I can't click on the button that runs the method berechnen() because the app crashes after I start it.
I'm confused why my program doesn't work. When I delete all imports of exp4j and delete the source for the calculation, my calculator works fine.
My only idea is that the exp4j libaries is using a class or method that does not exist in Android.
Thank you.
You may have include jars twice, check once in libs folder and libraries in properties, I have faced same in the past What you need to do is to
Remove that in the libraries and paste freshly in your res/lib folder of android application project and then clear your project
Related
I know this question has been asked before but I can't find the solution in previous solutions. The error points to the file Game.java. The code for that file is very simple:
package framework;
public interface Game {
public Input getInput();
public FileIO getFileIO();
public Graphics getGraphics();
public Audio getAudio();
public void setScreen(Screen screen);
public Screen getCurrentScreen();
public Screen getStartScreen();
}
I have used the file several times before without problems. I have updated the manifest file. I have updated Android Studio and all the plug-ins (in fact I have re-installed them). The project was created using Android Studio instead of being imported. I have tried cleaning the project. I just can't see what the problem is. Can you please help?
The location of the problem is
G:\AndroidStudioProjects\Marvelous2\app\src\main\res\framework\Game.java
You shouldn't place Java files under the res folder, those belong under src/main/java. Correct directory for Game.java is src/main/java/framework/Game.java.
When I attempt to deploy my app using Eclipse it throws FileNotFoundException on my font, which I've now copied to both the assets/src and assets directory to be doubly sure.
I had this problem before, after succesfully integrating SDL_ttf into my Visual C++ build of the same app and transferring across to Eclipse for Android. Now I'm facing it again I thought I better write about it. The SDL_ttf source comes with a freetype folder already in place and referenced by android as external/freetype-2.4.12. DinoMage states I need to download this separately although he refers to freetype-2.4.11 being the latest. That's the only obvious difference from my VC build, apart from minor compiler intolerances.
I've got it working a bit now. I can sign the app (unsigned didn't work), disable USB debugging, and it will load the font and display a menu. From there it breaks, again, so I can't see how I'm supposed to debug it further. I'm sure I'll fix it somehow. But I'll also forget the obscura if I don't post here.
I don't know much about using the debugger with Android, but I can make suggestions otherwise.
Is your assets path really named "assetts"? If possible, I'm not sure how one would get Android and SDL to look there instead of "assets".
SDL and it's friend libs like SDL_ttf search for files local to the assets directory first and then search relative to the root directory. So I would expect that your "res/stubbornFont.ttf" will never load because it is in the resources "res" directory and SDL_ttf will not look there.
Maybe you can specify it relative to assets/, like "../res/stubbornFont.ttf", but I haven't tested that. It would work if you put the font in assets/ and loaded it as "stubbornFont.ttf".
I've think I've got closure on this.
It is possible to debug the app. By continuing it will trap several times trying to load one font. I think it stops eventually, I'm not sure. I've stepped through it from where it lands me at the throw stage. However single stepping from there begins from the synchronized statement, sorry it's Java but from my quick reference to What does 'synchronized' mean? I think this is a race condition
public final AssetFileDescriptor openFd(String fileName)
throws IOException {
synchronized (this) {
if (!mOpen) {
throw new RuntimeException("Assetmanager has been closed");
}
ParcelFileDescriptor pfd = openAssetFd(fileName, mOffsets);
if (pfd != null) {
return new AssetFileDescriptor(pfd, mOffsets[0], mOffsets[1]);
}
}
throw new FileNotFoundException("Asset file: " + fileName);//DEBUGGER traps here
}
You might be there all day single stepping that! It appears to perform all steps required of it and finally I land in:
public static ReadableByteChannel newChannel(InputStream inputStream) {
return new InputStreamChannel(inputStream);
}
No, not finally, lastly, there is
public static Context getContext() {
return mSingleton;
}
In the SDLActivity I extend.
That has a bunch of members I don't want to know about:
Luckily I discovered I can selectively "Disconnect" using a button in eclipse two along from debug/run. It has no keyboard shortcut and I'm not sure why but it will reconnect when I next trigger an exception. This is debugging as I know and love it in Android and Eclipse, still probably easier than GDB.
For arguments sake I've even replaced:
//TTF_Font *gFont = TTF_OpenFont( "res/stubbornFont.ttf", 160 );
with
TTF_Font *font=TTF_OpenFontRW(SDL_RWFromFile("res/stubbornFont.ttf", "rb"), 1, 160);//Same difference
UPDATE/EDIT
Here is the solution I was really looking for,
turning off uncaught exceptions in eclipse, it really is just that, Window->Preferences->Java->Debug and it's the very first box at the top for me.
I am having trouble importing the zbar library properly.
I am following this guide:
https://github.com/DushyanthMaguluru/ZBarScanner
The guide says:
Download this project and add it as a library project to your existing Android app
I downloaded this project and created a library from ZbarScannerLibary folder. I then set in the properties of my project this liabry to be used.
I then continued the guide, when I started to code the main activity I received errors that variables and imports cannot be resolved.
What am I doing wrong and how can I get the imports to be resolved ?
just create a variable in your Activity:
public static final int ZBAR_SCANNER_REQUEST = 0;
public static final int ZBAR_OR_SCANNER_REQUEST = 1;
//etc
These are just used for handling activity result. In the short run, you can also comment out the onActivityResult method to test the barcode is working. You then open the barcode with:
startActivity(intent);
Finally, be sure to read up on startActivityForResult, since it is a very important topic when developing a multi-activity app.
I'm porting a simple tetris-like XNA app to Android, using Mono For Android and MonoGame; I have followed the suggested steps in this link and so far, everything compiles well, and no relevant warnings fire up. However, upon loading the contents, a null parameter exception breaks the program at the point below in my program:
protected override void LoadContent() {
// ...
_font = Content.Load<Microsoft.Xna.Framework.Graphics.SpriteFont>("SpriteFont1");
// ...
}
The content root directory is set in the game constructor class:
public Game2 (){
Content.RootDirectory = "Content";
Content.RootDirectory = "Assets/Content"; // TEST.
//...}
And I have tried several combinations, all to no avail.
I have also tried setting the xnb files as Content as well as Android Assets in the Build Action property; having the linked, copied always, copied only if newer... etc.
Either way, my problem is that I don't really understand WHY and HOW should I do this. I'm rather new to the platform and to XNA as well, so this may very well be a newbie question, but the truth is after several hours banging my head and fists against the monitor/keyboard I feel stuck and need your help.
I have a library that supports variable-width fonts (generated by BMFont) on MonoGame. Unfortunately it is a renderer and so has other code around it. However, the basic idea is very simple. You can take a look at the loader here and the mesh builder (given a string) here. This builder supports fonts that spread characters across multiple pages, too.
Hope this helps!
MonoGame (2.5.1) throws NotImplementedException in ContentManager.Load for SpriteFont type. Have the same not resolved problem. I'm trying not to use DrawString.
For loading textures in Win32 application I use:
Content.RootDirectory = #"../../Content";
var sampleTexture = Content.Load<Texture2D>("Sample.png");
You even must not add it to solution.
For Andoind (MonoDroid) application you must add "Content" folder to your solution and set "Andtoid Asset" in "Sample.png" properties.
Content.RootDirectory = "Content";
var sampleTexture = Content.Load<Texture2D>("Sample.png");
See also:
http://monogame.codeplex.com/discussions/360468
http://monogame.codeplex.com/discussions/267900
I'm having trouble getting Eclipse to see that I've just put a new image into my project when referencing that image using R.drawable.this_text
So I drag my png into myProject/res/drawable-hdpi in Eclipse's Project Explorer. The name of the image is this_text and it's a png!
So I go into my application and I want to put this on the screen; So here's the code for that...
private void setTitle()
{
ImageView title = new ImageView(this); //this extends activity
title.setBackgroundResource(R.drawable.this_text);
...
}
This I have done before and each time I do it I experience the same thing:
if i just dragged my this_text.png into the Project Explorer in eclipse, the word "this_text" will be underlined in red, and not allow me to compile or proceed. I try to F5 (refresh) the project. I try refreshing the image foldr, the src, the actual java...etc! I try closing and opening eclipse but nothing really works. So I quit for afew minutes and work elsewhere in my application, and eventually this error goes away!
Well I'm impatient today-- And I'd rather know how to solve this incase I need to do any quick programming! So does anyone know what to do?
I'm using eclipse Version: Indigo Service Release 1.
Thanks- Ethan
R files for android are generated. Rather than refreshing you should be able to CLEAN the project which should fix your issue. You could even just delete the error from the problems list which would allow for compilation to start and for the generated R file to be created. Or you could make a change to an xml which would also allow for the file to be regened. As always make sure you are up to date on your tool chain.