我在使用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,我写了这样的图像来显示这个位置的图像。在Java中加载图像J2ME
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) {
}
}
它表明我这个错误:
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)
我开始学习如何开发,所以请大家指导做到这一点。
检查文件名是否正确。图像加载器是区分大小写的,甚至文件名“picture.Png”,你会得到例外... – 2009-11-24 12:59:17