JavaMe MIDlet和Canvas
我正在尝试制作一个使用midlet作为菜单的程序。当从菜单访问某些命令时，它将访问画布（如在弹出按钮中选择fillrectangle和fillarc）。如果我选择了fillrectangle，它将访问绘制填充矩形的画布。
问题是当我访问fillarc时没有任何反应，但是在fillrectangle上它确实发生了。
另一个问题是我不知道如何将菜单中的X和Y坐标应用于fillrectangle，以便用户控制所选对象的位置。 “
这是我的代码：
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
/**
* @author Nico
*/
public class emp extends MIDlet implements CommandListener {
Display display;
Form frm = new Form ("Main");
ChoiceGroup Cg1;
ChoiceGroup Cg2;
TextField tfX = new TextField ("X Axis"," ",40,TextField.ANY);
TextField tfY = new TextField ("Y Axis"," ",40,TextField.ANY);
Command OK;
public emp () {
OK = new Command ("OK",Command.OK,1);
Cg2 = new ChoiceGroup("Color", Choice.POPUP);
Cg1 = new ChoiceGroup("Type", Choice.POPUP);
Cg1.append("Rectangle", null);
Cg1.append("Arc", null);
Cg1.append("Line", null);
Cg2.append("Red", null);
Cg2.append("Blue", null);
Cg2.append("Green", null);
frm.append(Cg1);
frm.append(tfX);
frm.append(tfY);
frm.append(Cg2);
frm.addCommand(OK);
frm.setCommandListener(this);
}
public void startApp () {
display = Display.getDisplay(this);
display.setCurrent(frm);
}
public void pauseApp () {}
public void destroyApp (boolean forced) {}
class DrawingRect extends Canvas implements CommandListener {
Command Bk;
public DrawingRect (){
this.addCommand(Bk= new Command("Back", Command.BACK, 0 ) );
this.setCommandListener(this);
}
public void paint (Graphics g) {
int x1=100,y1=100;
g.setColor (0, 0, 0);
g.fillRect(0, 0, getWidth(), getHeight());
g.setColor (0, 0, 255);
g.fillRect(x1,y1, 50, 50);
g.drawString("aaaaaa", getWidth()/2, getHeight()/2, Graphics.TOP|Graphics.HCENTER);
}
public void commandAction(Command c, Displayable d) {
if (c==Bk){
display.setCurrent(frm);
}
}
}
public class DrawingArc extends Canvas implements CommandListener {
Command Bk;
public DrawingArc (){
this.addCommand(Bk= new Command("Back", Command.BACK, 0 ) );
this.setCommandListener(this);
}
public void paint (Graphics g) {
g.setColor (0, 0, 0);
g.fillRect(0, 0, getWidth(), getHeight());
g.setGrayScale(13*16);
g.fillArc(0,0,getWidth(),getHeight(),90,360);
}
public void commandAction(Command c, Displayable d) {
if (c==Bk){
display.setCurrent(frm);
}
}
}
public void commandAction(Command c, Displayable d) {
if (c==OK) {
int select = Cg1.getSelectedIndex();
if (select==0){
display.setCurrent (new DrawingRect ());
}
}
else if (c==OK){
int select = Cg1.getSelectedIndex();
if (select==1){
display.setCurrent (new DrawingArc ());
}
}
else {
}
}
}
没有找到相关结果
已邀请:
1 个回复
绵扇寸访
public void commandAction(Command c, Displayable d) { if (c==OK) { int select = Cg1.getSelectedIndex(); if (select==0){ display.setCurrent (new DrawingRect ()); } }else if (c==OK){ // It will never ever ever reach this block int select = Cg1.getSelectedIndex(); if (select==1){ display.setCurrent (new DrawingArc ()); } }else { // WTF? } }public void commandAction(Command c, Displayable d) { if (c==OK) { int select = Cg1.getSelectedIndex(); if (select==0){ display.setCurrent (new DrawingRect ()); }else if (select==1){ display.setCurrent (new DrawingArc ()); } } }按钮。如果按下它，可以使用给定的X和Y创建画布，或者......下面的一些提示：class DrawingRect extends Canvas implements CommandListener { Command Bk; int x1, y1; public DrawingRect (int newX, int newY){ this.addCommand(Bk= new Command("Back", Command.BACK, 0 ) ); this.setCommandListener(this); x1 = newX; y1 = newY; } public void paint (Graphics g) { g.setColor (0, 0, 0); g.fillRect(0, 0, getWidth(), getHeight()); g.setColor (0, 0, 255); g.fillRect(x1,y1, 50, 50); g.drawString("aaaaaa", getWidth()/2, getHeight()/2, Graphics.TOP|Graphics.HCENTER); } public void commandAction(Command c, Displayable d) { if (c==Bk){ display.setCurrent(frm); } } }但是，所有这些都是非常基本的Java概念，我认为你应该在进一步改进之前改进它们......只是一个建议。