问题描述
我已经开发为重点，从JTextComponent的丢失这验证项摆动形式
如果项是正确的，背景涂成绿色，否则它被涂成红色。
I have developed a swing form which validates entries as the focus is lost from JTextComponentand if the entry is correct ,the background is painted green Otherwise it is painted red.
下面是code： -
Here is the code :-
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.text.JTextComponent;
public class Form extends JFrame implements FocusListener{
JTextField fname,lname,phone,email,address;
BufferedImage img;
public static void main(String args[])
{
SwingUtilities.invokeLater(new Runnable(){public void run(){new Form();}});
}
public Form()
{
super("Form with Validation Capability");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(400,300);
setLayout(new GridLayout(5,3));
try {
img=ImageIO.read(new File("src/warning.png"));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
add(new JLabel("First Name :"));
add(fname=new JTextField(20));
add(new JLabel("Last Name :"));
add(lname=new JTextField(20));
add(new JLabel("Phone Number :"));
add(phone=new JTextField(10));
add(new JLabel("Email:"));
add(email=new JTextField(20));
add(new JLabel("Address :"));
add(address=new JTextField(20));
fname.addFocusListener(this);
lname.addFocusListener(this);
phone.addFocusListener(this);
email.addFocusListener(this);
address.addFocusListener(this);
setVisible(true);
}
public void focusGained(FocusEvent e)
{
((JTextComponent) e.getSource()).setBackground(Color.WHITE);
}
public void focusLost(FocusEvent e)
{
if(e.getSource().equals(fname))
{
validationForText(fname);
}
else if(e.getSource().equals(lname))
{
validationForText(lname);
}
else if(e.getSource().equals(email))
{
validationForEmail(email);
}
else if(e.getSource().equals(phone))
{
validationForNumber(phone);
}
else{
((JTextComponent) e.getSource()).setBackground(Color.GREEN);
}
}
public void validationForText(JTextComponent comp)
{
String temp=comp.getText();
if (temp.matches("^[A-Za-z]+$")) {
comp.setBackground(Color.GREEN);
}
else
comp.setBackground(Color.RED);
}
public void validationForNumber(JTextComponent comp)
{
String text=comp.getText();
if(text.matches("^[0-9]+$"))
comp.setBackground(Color.GREEN);
else
comp.setBackground(Color.RED);
}
public void validationForEmail(JTextComponent comp)
{
String text=comp.getText();
if(text.matches("[^@]+@([^.]+\\.)+[^.]+"))
comp.setBackground(Color.GREEN);
else
comp.setBackground(Color.RED);
}
}
下面是输出到我的简单的应用程序：
Here is the output to my simple app :
现在我也想战平不正确field.Can人的左下角警告符号（缓冲图像）帮助我如何做到这一点，因为我不理解的地方绘制图像。
（我想这样做使用的JLayeredPane它作为我学习的应用，任何code段将真正帮助）。
Now I also want to draw a warning symbol (buffered image) at the lower left corner of incorrect field.Can anyone help me how to do this as i am not understanding where to paint the image.(I would like to do it using JLayeredPane as I am learning its application,any code snippet will really help).
推荐答案
为什么不直接添加的JLabel （使用合适的的LayoutManager 将它定位）与内置的Swing警告图标 UIManager.getIcon（OptionPane.warningIcon）
Why not simply add a JLabel (using an appropriate LayoutManager to position it) with the inbuilt Swing warning icon UIManager.getIcon("OptionPane.warningIcon")
像这样：
JLabel label=new JLabel(UIManager.getIcon("OptionPane.warningIcon"));
的rel=\"nofollow\">更多
see here for more.
更新：
根据您的意见，我宁愿用玻璃面板（并添加的JLabel 来的glassPane），这个相太的JLayeredPane 。请参见更多关于组件，rootPanes
As per your comment I would rather use GlassPane (and add JLabel to glasspane) for this as opposed too JLayeredPane. See here for more on RootPanes
的几点建议：
-
不要延长
的JFrame不必要的
不要调用的setSize 在的JFrame 。使用正确的的LayoutManager 和/或覆盖的get preferredSize（）在必要时，更换的setSize 与包（） 之前设置的JFrame 可见。
Dont call setSize on JFrame. Use a correct LayoutManager and/or override getPreferredSize() where necessary and replace setSize call with pack() just before setting JFrame visible.
不要实施的FocusListener 的类。
此外养成使用习惯 FocusAdapter VS 的FocusListener 适用于一些具有附加监听器即的MouseListener 可以被替换为 MouseAdapter 。这让我们只重写我们想要的方法。在这种情况下，监听器是正确的，因为我们做两个重载方法的东西，但就像我说的更多的关于习惯
Also get into the habit of using FocusAdapter vs FocusListener this applies to a few with appended Listener i.e MouseListener can be replaced for MouseAdapter. This allows us to only override the methods we want. In this case listener is correct as we do something on both overridden methods, but as I said more about the habit
另外随时拨打 super.XXX 实施覆盖的方法，即 focusGained（FocusEvent FE）除非你被忽视它的一个原因
Also always call super.XXX implementation of overridden methods i.e focusGained(FocusEvent fe) unless you are ignoring it for a reason
下面是code以上修正，包括的glassPane以示警告图标时，现场为红色：
Here is code with above fixes including glasspane to show warning icon when field is red:
和删除它被纠正时：
import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.RenderingHints;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;
import java.awt.image.BufferedImage;
import java.util.HashMap;
import java.util.Map;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.text.JTextComponent;
/**
*
* @author David
*/
public class GlassValidationPane extends JComponent {
private static JTextField fname, lname, phone, email, address;
private static GlassValidationPane gvp = new GlassValidationPane();
public static void main(String args[]) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
JFrame f = new JFrame("Form with Validation Capability");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//f.setResizable(false);
f.setLayout(new GridLayout(5, 3));
f.add(new JLabel("First Name :"));
f.add(fname = new JTextField(20));
f.add(new JLabel("Last Name :"));
f.add(lname = new JTextField(20));
f.add(new JLabel("Phone Number :"));
f.add(phone = new JTextField(10));
f.add(new JLabel("Email:"));
f.add(email = new JTextField(20));
f.add(new JLabel("Address :"));
f.add(address = new JTextField(20));
f.addComponentListener(new ComponentAdapter() {
@Override
public void componentResized(ComponentEvent ce) {
super.componentResized(ce);
gvp.refreshLocations();
}
});
FocusAdapter fl = new FocusAdapter() {
@Override
public void focusGained(FocusEvent fe) {
super.focusGained(fe);
((JTextComponent) fe.getSource()).setBackground(Color.WHITE);
}
@Override
public void focusLost(FocusEvent fe) {
super.focusLost(fe);
if (fe.getSource().equals(fname)) {
validationForText(fname);
} else if (fe.getSource().equals(lname)) {
validationForText(lname);
} else if (fe.getSource().equals(email)) {
validationForEmail(email);
} else if (fe.getSource().equals(phone)) {
validationForNumber(phone);
} else {
gvp.removeWarningIcon(((Component) fe.getSource()));
((JTextComponent) fe.getSource()).setBackground(Color.GREEN);
}
}
};
fname.addFocusListener(fl);
lname.addFocusListener(fl);
phone.addFocusListener(fl);
email.addFocusListener(fl);
address.addFocusListener(fl);
f.setGlassPane(gvp);
f.pack();
f.setVisible(true);
gvp.setVisible(true);
}
public void validationForText(JTextComponent comp) {
String temp = comp.getText();
if (temp.matches("^[A-Za-z]+$")) {
setGreen(comp);
} else {
setRed(comp);
}
}
public void validationForNumber(JTextComponent comp) {
String text = comp.getText();
if (text.matches("^[0-9]+$")) {
setGreen(comp);
} else {
setRed(comp);
}
}
public void validationForEmail(JTextComponent comp) {
String text = comp.getText();
if (text.matches("[^@]+@([^.]+\\.)+[^.]+")) {
setGreen(comp);
} else {
setRed(comp);
}
}
private void setRed(JTextComponent comp) {
comp.setBackground(Color.RED);
gvp.showWarningIcon(comp);
}
private void setGreen(JTextComponent comp) {
comp.setBackground(Color.GREEN);
gvp.removeWarningIcon(comp);
}
});
}
private HashMap<Component, JLabel> warningLabels = new HashMap<>();
private ImageIcon warningIcon;
public GlassValidationPane() {
setLayout(null);//this is the exception to the rule case a layoutmanager might make setting Jlabel co-ords harder
setOpaque(false);
Icon icon = UIManager.getIcon("OptionPane.warningIcon");
int imgW = icon.getIconWidth();
int imgH = icon.getIconHeight();
BufferedImage img = ImageUtilities.getBufferedImageOfIcon(icon, imgW, imgH);
warningIcon = new ImageIcon(ImageUtilities.resize(img, 24, 24));
}
void showWarningIcon(Component c) {
if (warningLabels.containsKey(c)) {
return;
}
JLabel label = new JLabel();
label.setIcon(warningIcon);
//int x=c.getX();//this will make it insode the component
int x = c.getWidth() - label.getIcon().getIconWidth();//this makes it appear outside/next to component
int y = c.getY();
label.setBounds(x, y, label.getIcon().getIconWidth(), label.getIcon().getIconHeight());
add(label);
label.setVisible(true);
revalidate();
repaint();
warningLabels.put(c, label);
}
public void removeWarningIcon(Component c) {
for (Map.Entry<Component, JLabel> entry : warningLabels.entrySet()) {
Component component = entry.getKey();
JLabel jLabel = entry.getValue();
if (component == c) {
remove(jLabel);
revalidate();
repaint();
break;
}
}
warningLabels.remove(c);
}
public void refreshLocations() {
for (Map.Entry<Component, JLabel> entry : warningLabels.entrySet()) {
Component c = entry.getKey();
JLabel label = entry.getValue();
//int x=c.getX();//this will make it insode the component
int x = c.getWidth() - label.getIcon().getIconWidth();//this makes it appear outside/next to component
int y = c.getY();
label.setBounds(x, y, label.getIcon().getIconWidth(), label.getIcon().getIconHeight());
revalidate();
repaint();
}
}
}
class ImageUtilities {
public static BufferedImage resize(BufferedImage image, int width, int height) {
BufferedImage bi = new BufferedImage(width, height, BufferedImage.TRANSLUCENT);
Graphics2D g2d = (Graphics2D) bi.createGraphics();
g2d.addRenderingHints(new RenderingHints(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY));
g2d.drawImage(image, 0, 0, width, height, null);
g2d.dispose();
return bi;
}
public static BufferedImage getBufferedImageOfIcon(Icon icon, int imgW, int imgH) {
BufferedImage img = new BufferedImage(imgW, imgH, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = (Graphics2D) img.getGraphics();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
icon.paintIcon(null, g2d, 0, 0);
g2d.dispose();
return img;
}
}
这篇关于在Swing表单验证期间将警告标志的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！