pack()方法
在做awt相关的练习时有时用到pack()方法,想知道这个方法的作用是什么呢?什么时候要用这个方法呢?
------解决方案--------------------关于pack()方法
在 Frame 类中有一个从类 java.awt.Window 继承的方法 pack()
show() 同样也继承自 java.awt.Window
public void pack()
调整此窗口的大小,以适合其子组件的首选大小和布局。如果该窗口和/或其所有者仍不可显示,则两者在计算首选大小之前变得可显示。在计算首选大小之后,将会验证该 Window。
------解决方案--------------------public void pack()
Causes this Window to be sized to fit the preferred size and layouts of its subcomponents. If the window and/or its owner are not yet displayable, both are made displayable before calculating the preferred size. The Window will be validated after the preferredSize is calculated.
意思就是说,自动调整窗口首选大小和布局,去适应该窗口的容器组建。如果这个窗口和它的容器之前没有显示出来的话,在计算首选大小之前,先显示出它们。那样的话,在首选大小被计算出来之后,就能正确显示了...
------解决方案--------------------一般在你将控件放置在容器之后,调用这个pack()方法...
给分吧 呵呵
------解决方案--------------------javaDoc:
调整此窗口的大小,以适合其子组件的首选大小和布局。
javaSrc:
Java code
/**
* Causes this Window to be sized to fit the preferred size
* and layouts of its subcomponents. If the window and/or its owner
* are not yet displayable, both are made displayable before
* calculating the preferred size. The Window will be validated
* after the preferredSize is calculated.
* @see Component#isDisplayable
*/
public void pack() {
Container parent = this.parent;
if (parent != null && parent.getPeer() == null) {
parent.addNotify();
}
if (peer == null) {
addNotify();
}
Dimension newSize = getPreferredSize();
if (peer != null) {
setClientSize(newSize.width, newSize.height);
}
if(beforeFirstShow) {
isPacked = true;
}
validate();
}