在Java J2ME中加载图像 [英] Loading image in Java J2ME
本文介绍了在Java J2ME中加载图像的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我在用Java 2ME加载图像时遇到问题.我在位置驱动器"C:"中有一个图像文件"picture.png".之后,我这样写了我的照片,以显示该位置的图像.
I have a problem with loading image with java 2ME. I have a image file "picture.png" in location drive "C:". After that I wrote my like this to show image from this location.
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import java.io.*;
public class ImageMidlet extends MIDlet implements CommandListener{
private Display display;
private Command exitCommand;
private Command backCommand;
private Command okCommand;
private Form form;
private ImageItem imageItem;
private Image image;
public ImageMidlet(){
display = Display.getDisplay(this);
form=new Form("");
exitCommand = new Command("Exit", Command.EXIT, 1);
backCommand = new Command("Back", Command.BACK, 2);
okCommand = new Command("OK", Command.OK, 3);
try {
image=Image.createImage("/picture.png");
imageItem=new ImageItem(null,image,ImageItem.LAYOUT_NEWLINE_BEFORE,"");
}
catch(IOException ex){
}
form.append(imageItem);
form.addCommand(okCommand);
form.addCommand(exitCommand);
form.addCommand(backCommand);
form.setCommandListener(this);
display.setCurrent(form);
}
public void commandAction(Command c,Displayable d){
}
public void startApp() {
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
}
}
它向我显示此错误:
Unable to create MIDlet Test.ImageMidlet
java.lang.NullPointerException
at javax.microedition.lcdui.Form.append(Form.java:638)
at Test.ImageMidlet.<init>(ImageMidlet.java:39)
at java.lang.Class.runCustomCode(+0)
at com.sun.midp.midlet.MIDletState.createMIDlet(+34)
at com.sun.midp.midlet.Selector.run(Selector.java:151)
我正在开始学习开发,所以请指导.
I am starting learn to develop, so please guide to do this.
推荐答案
如销售所述-您无法从计算机访问图像.确保已将给定图像包含在Midlet jar文件中.如果您尝试使用'/picture.png'访问它,那么它应该位于jar的根目录中.
As msell said - You can't access images from Your computer. Make sure that You have included the given image in midlet jar file. If You try to access it using '/picture.png', then it should be located a the root directory in jar.
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