Question

java中jframe的add方法

为什么下面两个语句的效果都能编译通过？
正确的不是 add(按钮，位置) 吗？
为什么 add(位置，按钮) 都可以？

c.add(new JButton("我是按钮"),BorderLayout.CENTER);
c.add(BorderLayout.CENTER,new JButton("我是按钮"));

Answer 1

/闭唤链**
* Adds the specified component to the end of this container.
* Also notifies the layout manager to add the component to
* this container's layout using the specified constraints object.
* This is a convenience method for {@link #addImpl}.
* <p>
* Note: If a component has been added to a container that
* has been displayed, <code>validate</code> must be
* called on that container to display the new component.
* If multiple components are being added, you can improve
* efficiency by calling <code>validate</code> only once,
* after all the components have been added.
*
* @param comp the component to be added
* @param constraints an object expressing
* layout contraints for this component
* @exception NullPointerException if {@code comp} is {@code null}
* @see #addImpl
* @see #validate
* @see javax.swing.JComponent#revalidate()
* @see LayoutManager
* @since JDK1.1
*/轿孙
public void add(Component comp, Object constraints) {
addImpl(comp, constraints, -1);
}

/**
* Adds the specified component to this container.
* This is a convenience method for {@link #addImpl}.
* <链陵p>
* This method is obsolete as of 1.1. Please use the
* method <code>add(Component, Object)</code> instead.
* @exception NullPointerException if {@code comp} is {@code null}
* @see #add(Component, Object)
*/
public Component add(String name, Component comp) {
addImpl(comp, name, -1);
return comp;
}
看源码。

追问

看不懂啊，能不能解释一下啊

追答

给你份中文的api自己看吧