Greenfoot

Kiara

2013/4/8

#

I am displaying text on the screen, and trying to make it so that with a specific text another actor will set another image. Please help as soon as you can!! This is the code

   StuffThatFlies stuffThatFlies;
 
    public Text(String words )
    {
        GreenfootImage img = new GreenfootImage(100, 50);
        img.drawString(words, 2, 20);
        setImage(img);
        if(words == "plane")
        {
            stuffThatFlies.setImage("airplane.png");
        }

I am getting a null pointer exception...

danpost

2013/4/8

#

You have not set 'stuffThatFlies' to anything. Maybe it should be:

StuffThatFlies stuffThatFlies = new StuffThatFlies();

Kiara

2013/4/8

#

How would that set the image for StuffThatFlies to be the airplane? @danpost

danpost

2013/4/8

#

That should get rid of the null pointer exception. By having the method recieve the string equal to "plane" will your code set the image to "airplane.png". You might need to change your test from if (words == "plane") to if ("plane".equals(words))

danpost

2013/4/8

#

Kiara wrote...

How would that set the image for StuffThatFlies to be the airplane? @danpost

This does not change the class image to be an airplane. It changes an instance of the class to be an airplane.

Kiara

2013/4/8

#

oh, I get it!!

Kiara

2013/4/8

#

So, how do I get it to look like a plane?

danpost

2013/4/8

#

You must have the image file for the airplane in the 'images' folder of the specific scenario you are working on. You can do this by right-clicking on the class icon and selecting 'Set image...'. Go to 'transportation' and select the "airplane.png" image and click OK. That will automatically move the file into the appropriate folder. You can repeat the process and select 'No image' to remove the default image for the class (the file will stay in the folder).

Kiara

2013/4/8

#

THANK YOU!! :)

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Text input with actors.