为什么此有关combobox的代码不起作用? [英] why this code about combobox doesn't work?

问题描述

我有一个组合框，用于存储计算机，代码:21"，历史记录，代码:31"，并且可以更改项数.但是当我编写此代码以获取其项时:

I have a combobox which stores "Computer ,Code:21","History ,Code:31" and also the number of items can be changed.but when I write this code for getting its items:

List<String> bIHELessons = new ArrayList<String>();
for (int i=0;i<jComboBox1.getItemCount();i++) {
   String lessons = (String) jComboBox1.getItemAt(i);
   if (lessons != null&& lessons.trim().length()!=0) {
      bIHELessons.add(lessons);
      System.out.println(bIHELessons.toString());
   }
}

它将在控制台中显示以下句子:

it will show these sentences in the console:

[Computer，Code = 21]

[Computer,Code=21]

[Computer，Code = 21，History，Code:31]

[Computer,Code=21, History,Code:31]

推荐答案

因为您要使用bIHELessons.add(..)附加到列表.随后的每个调用都会添加到已经打印的字符串上.

Because you are appending to the list with bIHELessons.add(..). Each subsequent call adds on to the already printed string.

如果您仍要添加到ArrayList并打印ArrayList中的当前项目，请使用System.out.println(bIHELessons.get(i));而不是现在使用的内容.我也不认为您需要使用toString()，因为您的对象已经是string类型.

If you want to still add to the ArrayList and print the current item that is in the ArrayList, then use System.out.println(bIHELessons.get(i)); rather than using what you are now. I also don't think you need to use toString() because your objects are already in the type string.

如果只想打印当前要迭代的字符串，请将System.out.println(bIHELessons.toString());更改为System.out.println(lessons);.

Change System.out.println(bIHELessons.toString()); to System.out.println(lessons); if you only want to print the string you are currently iterating on.

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