当我运行此代码时,我只看到一个空白(白色)面板,我想知道为什么。
这是我的代码:
Graph.java
public class Graph extends JPanel {
private static final long serialVersionUID = -397959590385297067L;
int screen=-1;
int x=10;
int y=10;
int dx=1;
int dy=1;
boolean shouldrun=true;
imageStream imget=new imageStream();
protected void Loader(Graphics g){
g.setColor(Color.black);
g.fillRect(0,0,x,y);
x=x+1;
y=y+2;
}
@Override
protected void paintComponent(Graphics g){
super.paintComponent(g);
while(shouldrun){
Loader(g);
try {
Thread.sleep(200);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
最佳答案
永远不要在 Event Dispatch Thread 上调用 Thread.sleep()
!!!
这会导致线程实际重绘屏幕并使控件响应停止执行任何操作。
For animations, use a Timer
。不必担心自己编写 while 循环,只需告诉 Timer
每隔一段时间触发一次,并更改 x
和 y
的值即可在那个计时器里面。像这样的东西:
// this is an **inner** class of Graph
public class TimerActionListener implements ActionListener {
@Override
public void actionPerformed(ActionEvent e) {
x += dx;
y += dy;
}
}
// snip
private final Timer yourTimer;
public Graph() {
yourTimer = new Timer(2000, new TimerActionListener());
timer.start();
}
@Override
protected void paintComponent(Graphics g){
super.paintComponent(g);
g.setColor(Color.black);
g.fillRect(0,0,x,y);
}
关于java - 为什么我的 while 循环在 PaintComponent 中不起作用?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/32172561/