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Thread: I'm trying to open a "FileOpenDialog"

  1. #1
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    Default I'm trying to open a "FileOpenDialog"

    I'm trying to open a "FileOpenDialog" but am getting two err msgs:

    1) openFileButton cannot be resolved or is not a field RTTCPSortSimMain.java

    2) RTTCPSortSimMain cannot be resolved to a variable
    public class OpenFileButtonListener implements ActionListener {
    		@Override
    		public void actionPerformed(ActionEvent e) {
    			if (e.getSource() == this.openFileButton) { // 1
    				final JFileChooser fc = new JFileChooser();
    				int returnVal = fc.showOpenDialog(RTTCPSortSimMain); //2
    				if (returnVal == JFileChooser.APPROVE_OPTION) {
    					File file = fc.getSelectedFile();
    					// This is where a real application would open the file.
    					// log.append("Opening: " + file.getName() + "." + newline);
    				} else {
    					// log.append("Open command cancelled by user." + newline);
    				}
    			}
    		}
    	}
    1) "openFileButton" is the name of the JButton
    2) "RTTCPSortSimMain" is the name of the class this all lives in

    What should I be using in these places instead?


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: I'm trying to open a "FileOpenDialog"

    This thread has been cross posted here:

    http://www.java-forums.org/new-java/46215-im-trying-open-fileopendialog.html#post220738

    Although cross posting is allowed, for everyone's benefit, please read:

    Java Programming Forums Cross Posting Rules

    The Problems With Cross Posting


  3. #3
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    Default Re: I'm trying to open a "FileOpenDialog"

    ok, well you are saying this.openFileButton. I believe your problem is you are misinterpretting what this is referencing to. The keyword this references to the class that contains the keyword. So, when you have a nested class (such as the one I assume you have above), this is referring to the nested class, not the outer class.

    Look at the code below:
    public class OuterClass
    {	
    	int var = 0;
     
    	public OuterClass()
    	{
    		System.out.println(this.var); //References OuterClass's var variable
    	}
    	public class InnerClass
    	{
    		int var = 0;
     
    		public InnerClass()
    		{
    			System.out.println(this.var); //References InnerClass's var variable
    		}
    		public class InnerInnerClass
    		{
    			int var = 0;
     
    			public InnerInnerClass()
    			{
    				System.out.println(this.var); //References InnerInnerClass's var variable
    			}
    		}
    	}
    }

    Now, if you wanted to reference OuterClass's var variable from inside the InnerClass (by using the keyword this), you would have to say:
    public class OuterClass
    {	
    	int var = 0;
     
    	public OuterClass()
    	{
    		System.out.println(this.var); //References OuterClass's var variable
    	}
    	public class InnerClass
    	{
    		int var = 0;
     
    		public InnerClass()
    		{
    			System.out.println(OuterClass.this.var); //References OuterClass's var variable
    		}
    	}
    }

    Does that make sense? And could that be your problem?
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  4. The Following User Says Thank You to aussiemcgr For This Useful Post:

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