Java JScrollPane赢得';不要在JPanel上滚动
我有一个JFrame,在其中我在一个大网格中绘制了很多图像。我的窗口不够大,无法容纳整个网格,因此我想使用一个JScrollPane,它允许我在窗口中显示网格的某些部分 我的问题是我不能滚动。当我这样做时,滚动条总是出现,它们似乎已经覆盖了整个区域 如您所见,滚动条给人的印象是整个区域都显示在窗口中。然而,如果我调整它的大小,你会注意到根本不是这样的 滚动条继续显示它们覆盖了整个区域 (请注意,网格中的数字实际上是16×16像素的图像,但为了制作一个最小、完整且可验证的示例,我将图像替换为坐标字符串。) 以下是我的代码,用于最小、完整和可验证的示例:Java JScrollPane赢得';不要在JPanel上滚动,java,swing,jscrollpane,Java,Swing,Jscrollpane,我有一个JFrame,在其中我在一个大网格中绘制了很多图像。我的窗口不够大,无法容纳整个网格,因此我想使用一个JScrollPane,它允许我在窗口中显示网格的某些部分 我的问题是我不能滚动。当我这样做时,滚动条总是出现,它们似乎已经覆盖了整个区域 如您所见,滚动条给人的印象是整个区域都显示在窗口中。然而,如果我调整它的大小,你会注意到根本不是这样的 滚动条继续显示它们覆盖了整个区域 (请注意,网格中的数字实际上是16×16像素的图像,但为了制作一个最小、完整且可验证的示例,我将图像替换为坐
import java.awt.Dimension;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class Main {
public static int[][] tiles;
public static void main(String[] args) {
Foo foo = new Foo();
foo.run();
}
}
class Foo {
public void run(){
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
Panel panel = new Panel();
panel.setPreferredSize(new Dimension(512,448));
JScrollPane scrollPane = new JScrollPane(panel);
scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
frame.add(scrollPane);
frame.setVisible(true);
frame.pack();
Main.tiles = new int[32][32];
while (true) {
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
panel.repaint();
}
}
}
class Panel extends JPanel {
public void paintComponent(Graphics g){
paintScreen(g);
}
private void paintScreen(Graphics g){
int x =0, y =0;
for (int i = 0; i < Main.tiles.length; i++) {
for (int j = 0; j < Main.tiles[i].length; j++){
g.drawString(i + " " + j, x*32, y*32);
y++;
}
y=0;
x++;
}
}
}
导入java.awt.Dimension;
导入java.awt.Graphics;
导入javax.swing.JFrame;
导入javax.swing.JPanel;
导入javax.swing.JScrollPane;
公共班机{
公共静态int[][]分幅;
公共静态void main(字符串[]args){
Foo-Foo=新的Foo();
foo.run();
}
}
福班{
公开募捐{
JFrame=新JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
面板=新面板();
面板。设置首选尺寸(新尺寸(512448));
JScrollPane scrollPane=新的JScrollPane(面板);
scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HorizontalScrollBar\uAlways);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL\u SCROLLBAR\u ALWAYS);
frame.add(滚动窗格);
frame.setVisible(true);
frame.pack();
Main.tiles=新整数[32][32];
while(true){
试一试{
睡眠(500);
}捕捉(中断异常e){
e、 printStackTrace();
}
panel.repaint();
}
}
}
类面板扩展了JPanel{
公共组件(图形g){
漆幕(g);
}
专用虚空漆幕(图形g){
int x=0,y=0;
对于(int i=0;i
所以我的问题是:
问:为什么
JScrollPane
不允许我滚动JPanel
?您的问题似乎在这里:
panel.setPreferredSize(new Dimension(512,448));
将JScrollPane持有的JPanel约束为特定大小,不允许其扩展。永远不要这样做。而是约束JScrollPane或其视图端口
e、 g
导入java.awt.Dimension;
导入java.awt.Graphics;
导入javax.swing.JFrame;
导入javax.swing.JPanel;
导入javax.swing.JScrollPane;
公共班机{
公共静态int[][]分幅;
公共静态void main(字符串[]args){
Foo-Foo=新的Foo();
foo.run();
}
}
福班{
公开募捐{
JFrame=新JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
面板=新面板();
//!!面板设置首选尺寸(新尺寸(512448));
JScrollPane scrollPane=新的JScrollPane(面板);
scrollPane.getViewport().setPreferredSize(新维度(512,448));
scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HorizontalScrollBar\uAlways);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL\u SCROLLBAR\u ALWAYS);
frame.add(滚动窗格);
frame.setVisible(true);
frame.pack();
Main.tiles=新整数[32][32];
while(true){
试一试{
睡眠(500);
}捕捉(中断异常e){
e、 printStackTrace();
}
panel.repaint();
}
}
}
类面板扩展了JPanel{
专用静态最终整数预值=1200;
专用静态最终int PREF_H=1200;
公共组件(图形g){
超级组件(g);
漆幕(g);
}
@凌驾
公共维度getPreferredSize(){
返回新维度(PREF_W,PREF_H);
}
专用虚空漆幕(图形g){
int x=0,y=0;
对于(int i=0;i
编辑
尝试根据程序员的建议改进版本:
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Rectangle;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.Scrollable;
public class Main {
public static int[][] tiles;
public static void main(String[] args) {
Foo foo = new Foo();
foo.run();
}
}
class Foo {
public void run() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
NumberPanel panel = new NumberPanel();
// !! panel.setPreferredSize(new Dimension(512,448));
JScrollPane scrollPane = new JScrollPane(panel);
// !! scrollPane.getViewport().setPreferredSize(new Dimension(512, 448));
scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
frame.add(scrollPane);
frame.setVisible(true);
frame.pack();
Main.tiles = new int[32][32];
while (true) {
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
panel.repaint();
}
}
}
class NumberPanel extends JPanel implements Scrollable {
private static final int PREF_W = 1200;
private static final int PREF_H = 1200;
private static final int VP_WIDTH = 512;
private static final int VP_HEIGHT = 448;
public void paintComponent(Graphics g) {
super.paintComponent(g);
paintScreen(g);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
private void paintScreen(Graphics g) {
int x = 0, y = 0;
for (int i = 0; i < Main.tiles.length; i++) {
for (int j = 0; j < Main.tiles[i].length; j++) {
g.drawString(i + " " + j, x * 32, y * 32);
y++;
}
y = 0;
x++;
}
}
@Override
public Dimension getPreferredScrollableViewportSize() {
return new Dimension(VP_WIDTH, VP_HEIGHT);
}
@Override
public int getScrollableBlockIncrement(Rectangle arg0, int arg1, int arg2) {
// TODO Consider improving
return 0;
}
@Override
public boolean getScrollableTracksViewportHeight() {
return false;
}
@Override
public boolean getScrollableTracksViewportWidth() {
return false;
}
@Override
public int getScrollableUnitIncrement(Rectangle arg0, int arg1, int arg2) {
// TODO Consider improving
return 0;
}
}
导入java.awt.Dimension;
导入java.awt.Graphics;
导入java.awt.Rectangle;
导入javax.swing.JFrame;
导入javax.swing.JPanel;
导入javax.swing.JScrollPane;
导入javax.swing.Scrollable;
公共班机{
公共静态int[][]分幅;
公共静态void main(字符串[]args){
Foo-Foo=新的Foo();
foo.run();
}
}
福班{
公开募捐{
JFrame=新JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
NumberPanel面板=新的NumberPanel();
//!!面板设置首选尺寸(新尺寸(512448));
JScrollPane scrollPane=新的JScrollPane(面板);
//!!scrollPane.getViewport().setPreferredSize(新维度(512,448));
scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HorizontalScrollBar\uAlways);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL\u SCROLLBAR\u ALWAYS);
frame.add(滚动窗格);
frame.setVisible(true);
frame.pack();
Main.tiles=新整数[32][32];
while(true){
试一试{
睡眠(500);
}捕捉(中断异常e){
e、 printStackTrace();
}
panel.repaint();
}
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Rectangle;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.Scrollable;
public class Main {
public static int[][] tiles;
public static void main(String[] args) {
Foo foo = new Foo();
foo.run();
}
}
class Foo {
public void run() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
NumberPanel panel = new NumberPanel();
// !! panel.setPreferredSize(new Dimension(512,448));
JScrollPane scrollPane = new JScrollPane(panel);
// !! scrollPane.getViewport().setPreferredSize(new Dimension(512, 448));
scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
frame.add(scrollPane);
frame.setVisible(true);
frame.pack();
Main.tiles = new int[32][32];
while (true) {
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
panel.repaint();
}
}
}
class NumberPanel extends JPanel implements Scrollable {
private static final int PREF_W = 1200;
private static final int PREF_H = 1200;
private static final int VP_WIDTH = 512;
private static final int VP_HEIGHT = 448;
public void paintComponent(Graphics g) {
super.paintComponent(g);
paintScreen(g);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
private void paintScreen(Graphics g) {
int x = 0, y = 0;
for (int i = 0; i < Main.tiles.length; i++) {
for (int j = 0; j < Main.tiles[i].length; j++) {
g.drawString(i + " " + j, x * 32, y * 32);
y++;
}
y = 0;
x++;
}
}
@Override
public Dimension getPreferredScrollableViewportSize() {
return new Dimension(VP_WIDTH, VP_HEIGHT);
}
@Override
public int getScrollableBlockIncrement(Rectangle arg0, int arg1, int arg2) {
// TODO Consider improving
return 0;
}
@Override
public boolean getScrollableTracksViewportHeight() {
return false;
}
@Override
public boolean getScrollableTracksViewportWidth() {
return false;
}
@Override
public int getScrollableUnitIncrement(Rectangle arg0, int arg1, int arg2) {
// TODO Consider improving
return 0;
}
}