JOptionPane输入对话框如何确定值是2还是JOptionPane.CANCEL_OPTION

Question

i use the following Code to get an InputDialog:

String c = JOptionPane.showInputDialog("Select number",JOptionPane.OK_OPTION);

I also want that the User only uses IntegerValues between 0 and 100. I handle this by the following code:

while(notAllowed){
    try{
        int t =Integer.parseInt(c);
        if(t==JOptionPane.CANCEL_OPTION)
        {
            notAllowed=false;
            cancel=true;
        }
        if(t<=100 && t>0 &&notAllowed)
            notAllowed=false;
    }
    catch( Exception err)
    {}
    if(notAllowed)
        c = JOptionPane.showInputDialog("Only Numbers between 1 and 100 are allowed");
    }

Now if the uses types the number 2 its like clicking the Cancel Button because the Value of JOptionPane.CANCEL_OPTION is also 2. So how can i find out if Cancel is clicked or the input Value is 2.

Answer 1

JOptionPane returns null if the user clicks on cancel. Otherwise the value will be returned. I figured that out using this small example:

public class JOptionPaneTest {

    public static void main(String[] args) {
        Object obj = JOptionPane.showInputDialog(null, "test", "test-text");
        System.out.println(obj);
    }

}