面试的题目

[qzdsq]

小妹刚学的,请各位大哥多多指,下面这个的作用,
private final TextField purchaseField;

purchaseField = new TextField("Buy:", "", 3, TextField.NUMERIC);

请问一下("Buy:", "", 3, TextField.NUMERIC)的意思,那位高手可否详细的说明一下??

[interhanchi]

TextField
public TextField(String text,
int columns)
throws HeadlessException
Constructs a new text field initialized with the specified text to be displayed, and wide enough to hold the specified number of columns. A column is an approximate average character width that is platform-dependent.

Parameters:
text - the text to be displayed. If text is null, the empty string "" will be displayed.
columns - the number of columns. If columns is less than 0, columns is set to 0.
Throws:
HeadlessException - if GraphicsEnvironment.isHeadless() returns true.
See Also:
GraphicsEnvironment.isHeadless()

[shxchenwind]

怎么会有四个参数??


java.awt.TextField()
java.awt.TextField(int)
java.awt.TextField(java.lang.String)
java.awt.TextField(java.lang.String, int)

我只发现这些,你的那个是如何搞成的??

[ses127127]

这段代码是自己写的还是从别的什么地方照搬的

[shoulders]

同意 －> hifan(Hifan On Line)

[hifan]

.....................
Java.awt.TextField没有这个构造函数啊~

那就是你自己写的类了~

TextField("Buy:", "", 3, TextField.NUMERIC);
如果这个类是我写的，他的意思就是 构造一个TextField，前面有一个JLabel写着"Buy:",然后这个TextField里面的初始值为""，然后这个TextField只接受数字，并且长度不得大于3。

这就是我的构造函数了~

[wangdong_hk]

同意 －> hifan(Hifan On Line)

[飘渺]

同意 －> hifan(Hifan On Line)

[qzdsq]

TextField.NUMERIC又表示什么??