当用户点击/按住鼠标按钮时,我试图使图像与鼠标一起移动。当用户按住鼠标(其中它与鼠标实时更新)时,我已经设法做到了这一点,但是,当我单击图像时,图像将其位置调整到更新的区域,这不是我想要它做的。我希望图像移动的唯一时间,如果它被点击是如果用户再次单击,第二次。假设用户点击位于(0,0)的图像,如果用户再次点击屏幕上的其他位置,那么位置现在是(x,y)。
我有:
@Override
public void mouseClicked(MouseEvent e) {
clickCount++;
if(clickCount % 2 == 0){
p.setLocation(e.getX(), e.getY());//p is just a panel that contains the img
repaint();
}
System.out.println("mouse clicked...");
}
更新代码:
public void mouseClicked(MouseEvent e) {
Object o = e.getSource();
if(o instanceof JPanel)
clickCount++;
if(clickCount % 2 == 0 && clickCount != 0){
p.setLocation(e.getX(), e.getY());
repaint();
}
System.out.println("mouse clicked " + clickCount + " times");
}
这更接近于工作,但是,如果您单击屏幕上的任何位置(在clickCount % 2 == 0之后),那么图像将移动。
当mouseClicked
被调用时,确定之前是否点击了某些内容,如果是,将对象移动到当前位置,如果不是,检查用户点击的内容是否可移动,并将其分配给一个变量(稍后您将使用该变量进行检查)。
一旦对象被移动,将引用设置为null
private JPanel clicked;
@Override
public void mouseClicked(MouseEvent e) {
if (clicked != null) {
clicked.setLocation(e.getX(), e.getY());
clicked = null;
} else {
// Figure out if any panel was clicked and assign
// a reference to clicked
}
}
<标题>运行的例子…听起来你想同时支持点击和拖动重定位,这有点。这很困难,因为两者所需的鼠标操作是不同的,所以您需要监视多个状态并对您可能处于的状态做出决定,例如……
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class MouseTest {
public static void main(String[] args) {
new MouseTest();
}
public MouseTest() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(null);
JPanel panel = new JPanel();
panel.setBackground(Color.RED);
panel.setSize(50, 50);
panel.setLocation(50, 50);
add(panel);
MouseAdapter ma = new MouseAdapter() {
private Point offset;
private Point clickPoint;
private JPanel clickedPanel;
@Override
public void mousePressed(MouseEvent e) {
// Get the current clickPoint, this is used to determine if the
// mouseRelease event was part of a drag operation or not
clickPoint = e.getPoint();
// Determine if there is currently a selected panel or nor
if (clickedPanel != null) {
// Move the selected panel to a new location
moveSelectedPanelTo(e.getPoint());
// Reset all the other stuff we might other was have set eailer
offset = null;
clickedPanel = null;
} else {
// Other wise, find which component was clicked
findClickedComponent(e.getPoint());
}
}
@Override
public void mouseReleased(MouseEvent e) {
// Check to see if the current point is equal to the clickedPoint
// or not. If it is, then this is part of a "clicked" operation
// meaning that the selected panel should remain "selected", otherwise
// it's part of drag operation and should be discarded
if (!e.getPoint().equals(clickPoint)) {
clickedPanel = null;
}
clickPoint = null;
}
@Override
public void mouseDragged(MouseEvent e) {
// Drag the selected component to a new location...
if (clickedPanel != null) {
moveSelectedPanelTo(e.getPoint());
}
}
protected void findClickedComponent(Point p) {
Component comp = getComponentAt(p);
if (comp instanceof JPanel && !comp.equals(TestPane.this)) {
clickedPanel = (JPanel) comp;
int x = p.x - clickedPanel.getLocation().x;
int y = p.y - clickedPanel.getLocation().y;
offset = new Point(x, y);
}
}
private void moveSelectedPanelTo(Point p) {
if (clickedPanel != null) {
int x = p.x - offset.x;
int y = p.y - offset.y;
System.out.println(x + "x" + y);
clickedPanel.setLocation(x, y);
}
}
};
addMouseListener(ma);
addMouseMotionListener(ma);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
}
标题>