二维数组列表
二维数组列表
提问于 2012-06-03 05:48:19
我听说过使用这样的二维数组：
String[][] strArr;但是，有没有办法用列表来做到这一点呢？
也许是这样的？
ArrayList<String><String> strList;并使用像这样的东西来添加它？
strList.add("hey", "hey");有没有办法做这样的事情？感谢您的帮助。
如果有就好了，因为我现在把字符串放入成对的两个不同的ArrayList中。
回答 10
Stack Overflow用户
回答已采纳
发布于 2012-06-03 05:49:06
您将使用
List<List<String>> listOfLists = new ArrayList<List<String>>();然后当你需要添加一个新的“行”时，你可以添加这个列表：
listOfLists.add(new ArrayList<String>());当我想在GUI中保存对多个Point列表的引用，以便可以绘制多条曲线时，我主要使用它。它工作得很好。
例如：
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.Stroke;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.List;
import javax.swing.*;
@SuppressWarnings("serial")
public class DrawStuff extends JPanel {
private static final int PREF_W = 400;
private static final int PREF_H = PREF_W;
private static final Color POINTS_COLOR = Color.red;
private static final Color CURRENT_POINTS_COLOR = Color.blue;
private static final Stroke STROKE = new BasicStroke(4f);
private List<List<Point>> pointsList = new ArrayList<List<Point>>();
private List<Point> currentPointList = null;
public DrawStuff() {
MyMouseAdapter myMouseAdapter = new MyMouseAdapter();
addMouseListener(myMouseAdapter);
addMouseMotionListener(myMouseAdapter);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setStroke(STROKE);
g.setColor(POINTS_COLOR);
for (List<Point> pointList : pointsList) {
if (pointList.size() > 1) {
Point p1 = pointList.get(0);
for (int i = 1; i < pointList.size(); i++) {
Point p2 = pointList.get(i);
int x1 = p1.x;
int y1 = p1.y;
int x2 = p2.x;
int y2 = p2.y;
g.drawLine(x1, y1, x2, y2);
p1 = p2;
}
}
}
g.setColor(CURRENT_POINTS_COLOR);
if (currentPointList != null && currentPointList.size() > 1) {
Point p1 = currentPointList.get(0);
for (int i = 1; i < currentPointList.size(); i++) {
Point p2 = currentPointList.get(i);
int x1 = p1.x;
int y1 = p1.y;
int x2 = p2.x;
int y2 = p2.y;
g.drawLine(x1, y1, x2, y2);
p1 = p2;
}
}
}
private class MyMouseAdapter extends MouseAdapter {
@Override
public void mousePressed(MouseEvent mEvt) {
currentPointList = new ArrayList<Point>();
currentPointList.add(mEvt.getPoint());
repaint();
}
@Override
public void mouseDragged(MouseEvent mEvt) {
currentPointList.add(mEvt.getPoint());
repaint();
}
@Override
public void mouseReleased(MouseEvent mEvt) {
currentPointList.add(mEvt.getPoint());
pointsList.add(currentPointList);
currentPointList = null;
repaint();
}
}
private static void createAndShowGui() {
JFrame frame = new JFrame("DrawStuff");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new DrawStuff());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}Stack Overflow用户
发布于 2014-07-04 14:20:39
你可以创建一个列表，
ArrayList<String[]> outerArr = new ArrayList<String[]>(); 并向其中添加其他列表，如下所示：
String[] myString1= {"hey","hey","hey","hey"};
outerArr .add(myString1);
String[] myString2= {"you","you","you","you"};
outerArr .add(myString2);现在您可以使用下面的双循环来显示所有列表中的所有内容
for(int i=0;i<outerArr.size();i++){
String[] myString= new String[4];
myString=outerArr.get(i);
for(int j=0;j<myString.length;j++){
System.out.print(myString[j]);
}
System.out.print("\n");
}Stack Overflow用户
发布于 2012-06-03 05:49:58
二维数组只是一个数组的数组。lists的模拟只是Lists的List。
ArrayList<ArrayList<String>> myList = new ArrayList<ArrayList<String>>();我承认，这不是一个很好的解决方案，特别是如果你想要一个三维或更多的结构。
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原文链接：
https://stackoverflow.com/questions/10866205
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