更改面板颜色

Question

i have a string which stores the name of a color. Through the help of this variable i need to change the panel background. how can it be done???

Answer 1

Create Map which contains the String name of the color and the actual Color object.

Edit:

Just noticed two other answers suggest using the getColor(...) method. That does not just magically work and you need to define the color in the system properties. I've never used system properties, but I believe you need to set them when you start the JVM.

Answer 2

If the colors are only going to be the ones that java supports, you could do something like the following:

private Color getColorByName(String colorName) {

    Field[] colorFields = Color.class.getDeclaredFields();
    for (Field field : colorFields) {
        if (field.getName().equals(colorName.toUpper())) {
            //check that this is in fact a static field,
            //to make sure it is one of the colors you are looking for
            int modifiers = field.getModifiers();
            if ((Modifiers.STATIC & modifiers != 0) 
                    && (Modifiers.PUBLIC & modifiers != 0)) {
                try{
                    return (Color)field.getValue(null);
                } catch (FieldNotFoundException ex) {
                    //Maybe put some additional handling in here if you need it
                }
            }
        }
    }
    //or return a default color
    return null;
}

A few notes:

1. This uses reflection, so it will be slower (although you could, technically use this to make a color map at startup of the application and just reference that).

2. It would make a lot more sense to make a color map as mentioned by other people above.

3. The best would be if the different systems sent you actual values - say rgb values in int or 0.0-1.0 double format. Then you could consistently give them the appropriate response.

My recommendation, if you must use the color name, would be that they give you a set of names you must support, and you have an error condition - either a default color, null, or throw an exception.

Hope this helps.