最小化 JFrame 后 JTextField 正在移动

Question

I have just finished a project and ran into a problem I could not find anywhere on the internet so far.

I have several JTextFields on a JPanel on a JFrame. When I open the frame, all text fields are in the right place. If I minimize the frame and open it again, all text fields are moved and smaller. These are photos of my frame before and after I minimize it.

Before:

After:

panel = new JPanel();
panel.setBounds(0, 0, 400, 175);
panel.setVisible(true);
frame.add(panel);

field0 = new JTextField();
field0.setBounds(10, 55, 120, 20);
field0.setVisible(true);
Frame.panel.add(field0);
        
field1 = new JTextField();
field1.setBounds(250, 55, 125, 20);
field1.setVisible(true);
Frame.panel.add(field1);
        
field2 = new JTextField();
field2.setBounds(10, 105, 365, 20);
field2.setVisible(true);
Frame.panel.add(field2);

Answer 1

Swing was designed to be used with layout managers. The job of the layout manager is to set the "size" and "location" of each components based on the preferred size of each component and the rules of the layout manager.

In your code the setBounds(...) code is only temporary. When the frame is resized, the layout manager is invoked and the proper size/location is assigned to all components.

So the solution is to not attempt to set the bounds manually but to use layout managers effectively.

Read the section from the Swing tutorial on Layout Managers for more information and working examples to get you started.

Based on your example picture I would suggest you can use the GridBagLayout . It will allow you to create a GUI using row and columns. You can also have components span several columns. I see the you have 5 rows and 3 columns. Download the working demo code from the tutorial and modify it for your requirements.

all text fields are moved and smaller.

Each Swing component should determine its own preferred size.

When you use:

field0 = new JTextField();

the preferred size is what you see.

The better way to create the text field is to use:

field0 = new JTextField(10);

Now the "10" will allow the text field to determines its preferred size to hold 10 "W" characters.

Also, Swing components are visible by default, so you need need to use setVisible(true) for every component.