java 无法让 FileNameExtensionFilter 工作
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Can not get FileNameExtensionFilter to work
提问by Aqeel Hussain
I can not get my JFileChooser to show only the extensions I want (text files).
我无法让我的 JFileChooser 只显示我想要的扩展名（文本文件）。
JFileChooser fc = new JFileChooser();
FileNameExtensionFilter textFilter = new FileNameExtensionFilter("Text Files","txt");
fc.addChoosableFileFilter(textFilter);
What am I doing wrong? if I remove the filter the text files show up. Question might seem silly, but I have tried to find a solution and my code looks the same as other examples. Maybe I am just brain-locked.
我究竟做错了什么？如果我删除过滤器，则会显示文本文件。问题可能看起来很愚蠢，但我试图找到解决方案，我的代码看起来与其他示例相同。也许我只是脑子被锁住了。
Thank you for your time
感谢您的时间
I tried the suggested approach and I still have the same problem. So there must be something wrong elsewhere. I will load the class code - maybe someone can spot what I am doing wrong:
我尝试了建议的方法，但仍然遇到同样的问题。所以一定是其他地方出了问题。我将加载课程代码 - 也许有人可以发现我做错了什么：
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.filechooser.FileNameExtensionFilter;
public class ButtonListener implements ActionListener {
private JFrame fr;
public ButtonListener (JFrame frame){
fr = frame;
}
public void actionPerformed(ActionEvent event) {
if(event.getSource() instanceof JButton) {
String action = event.getActionCommand();
if (action.equals("First text")){
JFileChooser fc = new JFileChooser();
FileNameExtensionFilter textFilter = new FileNameExtensionFilter("Text Files","txt");
fc.addChoosableFileFilter(textFilter);
int returnVal = fc.showOpenDialog(fr);
}
else if (action.equals("Second text")){
}
else {
System.out.println("Error in ButtonListener");
}
}
}
}
}
It is not finished, but it should still be able to handle then extension issues that I am having.
它还没有完成，但它应该仍然能够处理我遇到的扩展问题。
回答by Thorn
Try using setFileFilterinstead.
尝试使用setFileFilter。
I never used FileNameExtensionFilter, but it's nice that they added this convenience class to Java 1.6
我从未使用过 FileNameExtensionFilter，但很高兴他们将这个便利类添加到 Java 1.6
I have always just extended FileFilter and then override accept. Using my class defined below, you could then write
我一直只是扩展 FileFilter 然后覆盖接受。使用我在下面定义的类，然后您可以编写
chooser.setFileFilter(new OpenFileFilter("txt"));
/**
* This class defines which file types are opened (by default) by the program.
* This file filter is used to associate a single file type (extension) with the program.
* You could add more than one file type to the open file dialog using this class by repeatedly
* calling addFileFilter.
*/
import java.io.File;
import javax.swing.filechooser.*;
public class OpenFileFilter extends FileFilter {
public String fileExt = "";
String txtExt = ".txt";
public OpenFileFilter() {
this(".pxml"); //default file type extension.
}
public OpenFileFilter(String extension) {
fileExt = extension;
}
@Override public boolean accept(File f) {
if (f.isDirectory())
return true;
return (f.getName().toLowerCase().endsWith(fileExt));
}
public String getDescription() {
if(fileExt.equals(txtExt ))
return "Text Files (*" + fileExt + ")";
else
return ("Other File");
}
}
回答by Aqeel Hussain
I know your question was already answered, but just in case you didn't know... You could have also use you FileNameExtensionFilter and just do:
我知道您的问题已经得到解答，但以防万一您不知道...您也可以使用 FileNameExtensionFilter 并执行以下操作：
fc.setFileFilter(textFilter);
I was stuck on the same prob. as you for a while. ;)
我被困在同一个问题上。像你一会儿。;)
