JFrame needs to be resized before it can be displayed. The setbounds() method in JPanel does not work

JFrame,JPanel Summary of frequently encountered problems

Question 1 ： JFrame You need to resize to display the control

Sometimes I'm doing Java When designing the view interface , You will inadvertently find that you need to resize the window to display .

reason ：setVisible The position of is not correct .

Solutions ：

1. setVisible(true); It should be placed at the end of the code segment .

2. Join in
   setVisible(false);
   setVisible(true);
   Forced refresh interface .

Question two ： stay JPanel in setBounds() Method doesn't work

reason ：JPanel Of setLayout Layout and setBounds Methods conflict

Solutions ：

1. Cancel JPanel Layout
   setLayout(null);

2. no need JPanel change to the use of sth. Container Container to load components .