imagetest.java

J2EE的无线手机通讯运用软件

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import java.io.IOException;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.ByteArrayInputStream;
import javax.microedition.rms.*;

public class ImageTest extends MIDlet implements CommandListener
{
public static ImageTest instance;
public Image BgImage[] = new Image[3];
private Command cmdExit;
private Command pingbao;
public ImageCanvas canvas;
private ChooseBgCanvas choosebg;

private Display display; 
private RecordStore optionsStore;
private Alert alert;
private final String optionsName = "Image";
public int BgIndex;

public ImageTest()
{
	instance = this;
	cmdExit = new Command("Exit", Command.SCREEN, 2);
	pingbao = new Command("pingbao", Command.SCREEN, 2);
	canvas = new ImageCanvas();
	choosebg = new ChooseBgCanvas();
	try {
        BgImage[0]= Image.createImage("/bg1.png");
        BgImage[1]= Image.createImage("/bg2.png");
        BgImage[2]= Image.createImage("/bg3.png");

    } catch (Exception e) {}
}

public void startApp()
{
	canvas.addCommand(cmdExit);
	canvas.setCommandListener(this);
	display = Display.getDisplay(this); 
	display.setCurrent(canvas); 
	openOptions();
	restoreOptions();
	choosebg.SetBg(BgIndex);
}
public void exit()
{ destroyApp(true);
  notifyDestroyed();
}



public void pauseApp()
{   
        saveOptions();
 }
public void destroyApp(boolean unconditional)
{       
        saveOptions();
        closeOptions(); 
}
public void commandAction(Command command, Displayable
screen)
{

if (command == cmdExit)
{
	destroyApp(true);
	notifyDestroyed();
}

}
public void openOptions() {
        //open the record store
		try {
			optionsStore = RecordStore.openRecordStore(optionsName, false);
		} catch (Exception e) {
			alert.setString("Could not access options storage");
            display.setCurrent(alert);
			optionsStore = null;
		}
    }
public void saveOptions() {
        try {
			RecordStore.deleteRecordStore(optionsName);
		} catch (Exception e) {}
		
		try {
			//if recordstore have existed open a record store ,if not create
			optionsStore = RecordStore.openRecordStore(optionsName, true);
			ByteArrayOutputStream bufOut = new ByteArrayOutputStream();
			DataOutputStream dataOut = new DataOutputStream(bufOut);	
			dataOut.writeInt(BgIndex);
			dataOut.flush();
			byte[] buffer = bufOut.toByteArray();
			optionsStore.addRecord(buffer, 0, buffer.length);
		} catch (Exception e) {
		}
  }
public void restoreOptions() {
        byte[] buf = null;
		try {
			RecordEnumeration rsEmu =
				optionsStore.enumerateRecords(null, null, false);
			if (rsEmu.hasNextElement()) {
				buf = rsEmu.nextRecord();
			}
		} catch(Exception e) {}
		
		// close the record store
		try {
			optionsStore.closeRecordStore();
		} catch (Exception e) {}
		
		if (buf == null) {
			BgIndex = 0;
		}
		try {
			ByteArrayInputStream bufIn = new ByteArrayInputStream(buf);
			DataInputStream in = new DataInputStream(bufIn);
			
			BgIndex = in.readInt();
			bufIn = null;
			in = null;
		} catch (Exception e) {}
}

public void closeOptions() {
        if (optionsStore != null) {
            try {
                optionsStore.closeRecordStore();
                optionsStore = null;
            } catch (RecordStoreException ex) {
                alert.setString("Could not close options storage");
                display.setCurrent(alert);
            }
        }
    }
}