java怎样设置图片适应容器大小

Posted 2023-04-16

//你可以试试这个程序 和你说的差不多
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import java.util.*;

//SplitPaneDemo itself is not a visible component.
public class SplitPaneDemo extends JPanel
implements ListSelectionListener
private JLabel picture;
private JList list;
private JSplitPane splitPane;
private String[] imageNames = "Bird", "Cat", "Dog", "Rabbit", "Pig", "dukeWaveRed",
"kathyCosmo", "lainesTongue", "left", "middle", "right", "stickerface";
public SplitPaneDemo()

//Create the list of images and put it in a scroll pane.

list = new JList(imageNames);
list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
list.setSelectedIndex(0);
list.addListSelectionListener(this);

JScrollPane listScrollPane = new JScrollPane(list);
picture = new JLabel();
picture.setFont(picture.getFont().deriveFont(Font.ITALIC));
picture.setHorizontalAlignment(JLabel.CENTER);

JScrollPane pictureScrollPane = new JScrollPane(picture);

//Create a split pane with the two scroll panes in it.
splitPane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,
listScrollPane, pictureScrollPane);
splitPane.setOneTouchExpandable(true);
splitPane.setDividerLocation(150);

//Provide minimum sizes for the two SplitPaneDemo in the split pane.
Dimension minimumSize = new Dimension(100, 50);
listScrollPane.setMinimumSize(minimumSize);
pictureScrollPane.setMinimumSize(minimumSize);

//Provide a preferred size for the split pane.
splitPane.setPreferredSize(new Dimension(400, 200));
updateLabel(imageNames[list.getSelectedIndex()]);


//Listens to the list
public void valueChanged(ListSelectionEvent e)
JList list = (JList)e.getSource();
updateLabel(imageNames[list.getSelectedIndex()]);


//Renders the selected image
protected void updateLabel (String name)
ImageIcon icon = createImageIcon("images/" + name + ".gif");
picture.setIcon(icon);
if (icon != null)
picture.setText(null);
else
picture.setText("Image not found");



//Used by SplitPaneDemo2
public JList getImageList()
return list;


public JSplitPane getSplitPane()
return splitPane;


/** Returns an ImageIcon, or null if the path was invalid. */
protected static ImageIcon createImageIcon(String path)
java.net.URL imgURL = SplitPaneDemo.class.getResource(path);
if (imgURL != null)
return new ImageIcon(imgURL);
else
System.err.println("Couldn't find file: " + path);
return null;



/**
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
*/
private static void createAndShowGUI()

//Create and set up the window.
JFrame frame = new JFrame("SplitPaneDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
SplitPaneDemo splitPaneDemo = new SplitPaneDemo();
frame.getContentPane().add(splitPaneDemo.getSplitPane());

//Display the window.
frame.pack();
frame.setVisible(true);


public static void main(String[] args)
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable()
public void run()
createAndShowGUI();

);



参考技术A 取得容器的宽和高，然后把图片宽和高设置为容器的宽高

CSS 图片自适应容器

https://www.jb51.net/css/660677.html

经常有这样一个场景，需要让图片自适应容器的大小。

1、img标签的方式

我们马上就能想到，把width、height 设置为100%啊。来看一哈效果。

?

1 2 3

<div class=‘div1‘>     <img src="./peiqi.png" alt=""> </div>

?

1 2 3 4 5 6 7 8 9 10 11

.div1     width:500px;     height:400px;     border:1px solid black; .div1 img      /*     width: 100%;     height:100%;     */

这是正常的佩琪（如果图片比容器大的话，图片会超出容器）

?

1 2 3 4 5 6 7 8 9

.div1     width:500px;     height:400px;     border:1px solid black; .div1 img      width: 100%;     height:100%;

这是100%的佩琪

额，好像刚过完年。

虽然符合了自适应的要求，但是如图所见图片失真了。这种图片比容器小的情况强行将图片自适应的话图片就失真。如果说是单个图片（logo、占位图、等）按设计稿开发就可以了。但经常会遇到接口获取的不规则图片的情况，一般这种时候会将小于容器的话将其水平、垂直居中。
整理一下任务：

• 图片宽高都小于容器时垂直、水平居中
• 图片宽高都大于容器时保持宽高比将width或height充满容器

?

1 2 3 4 5 6 7 8 9

<div class=‘div1‘>      <img src="./peiqi.png" alt="">  </div>  <div class=‘div1‘>      <img src="./peiqi2.png" alt="">  </div>  <div class=‘div1‘>      <img src="./peiqi4.jpeg" alt="">  </div>

?

1 2 3 4 5 6 7 8 9 10 11 12 13

.div1       width:500px;       height:400px;       border:1px solid black;       display: table-cell;       vertical-align: middle;      .div1 img        max-width: 100%;       max-height: 100%;       display: block;       margin: auto;

max-height 这个属性会阻止 height 属性的设置值变得比 max-height 更大。
max-height 属性用来设置给定元素的最大高度. 如果height 属性设置的高度比该属性设置的高度还大,则height 属性会失效.

这种效果就舒服多了

2、背景图的方式

?

1 2 3

.div       background-size: contain;

background-size: contain; 把图像图像扩展至最大尺寸，以使其宽度和高度完全适应内容区域。

利用css的 background-size: contain; 属性就能进一步优化图片的宽高都小于容器的情况了。

上代码

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

div       height: 400px;       width: 500px;       border: 1px solid black;       background-repeat: no-repeat;       background-size: contain;       background-position: center;      .div1       background-image: url(./peiqi1.png);      .div2       background-image: url(./peiqi2.png);      .div3       background-image: url(./peiqi4.jpeg);

?

1 2 3

<div class=‘div1‘></div>   <div class=‘div2‘></div>   <div class=‘div3‘></div>

当然最后还得看需求，产品是咋要求的。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。