J2ME 简单的游戏选择界面

import javax.microedition.lcdui.Canvas; import javax.microedition.lcdui.Display; import javax.microedition.lcdui.Font; import javax.microedition.lcdui.Graphics; import javax.microedition.midlet.MIDlet; public class MainCanvas extends Canvas { private MIDlet midlet = null; private Display display = null; private int selected ; private int Width = -1 ; private int Height = -1 ; public static final int[] a = {0,1,2,3}; public static final String[] b = {"选项1","选项2","选项3","选项4"}; public MainCanvas(MIDlet m, Display d) { this.midlet = m; display = d; selected = a[0]; Font f = Font.getDefaultFont(); for(int i=0;i<b.length;i++){ int c = f.stringWidth(b[i]); if(c>Width){ Width = c ; } } Width = Width + 2*8; Height = f.getHeight() + 2*4 ; } protected void paint(Graphics g) { //// 清屏幕 // int color = g.getColor(); // g.setColor(0xFFFFFF); // g.fillRect(0, 0,Width, Height); // g.setColor(color); //// 计算 // int rectWidth = Width ; // int rectHeight = Height * b.length ; // int x = (getWidth() - rectWidth)/2; // int y = (getHeight() - rectHeight )/2; // // g.drawRect(x, y, getWidth(), getHeight()); // for(int j=0;j<b.length;j++){ // if(selected ==j){ // g.setColor(0x6699cc); // g.fillRect(x+1, y+j*Height+1, rectWidth-1, Height-1); // g.setColor(color); // } // g.drawString(b[j], x+8, y+j*Height+4, Graphics.LEFT|Graphics.TOP); // } int color = g.getColor(); g.setColor(0xFFFFFF); g.fillRect(0, 0, getWidth(), getHeight()); g.setColor(color); // 计算整个菜单的高度，宽度和（x,y） int rectWidth = Width; int rectHeight = Height * b.length; int x = (getWidth() - rectWidth) / 2; int y = (getHeight() - rectHeight) / 2; // 画矩形 g.drawRect(x, y, rectWidth, rectHeight); for (int i = 1; i < b.length; i++) { g.drawLine(x, y + Height * i, x + rectWidth, y + Height * i); } // 画菜单选项，并根据selected的值判断焦点 for (int j = 0; j < b.length; j++) { if (selected == j) { g.setColor(0x6699cc); g.fillRect(x + 1, y + j * Height + 1, rectWidth - 1, Height - 1); g.setColor(color); } g.drawString(b[j], x + 8, y + j * Height + 4, Graphics.LEFT | Graphics.TOP); } } public void keyPressed(int keyCode){ int action = this.getGameAction(keyCode); switch(action){ // case Canvas.FIRE: // printLabel(selected); // //display.setCurrent(this); //// repaint(); // break; case Canvas.DOWN: selected = (selected+1)%4; // repaint(); break; case Canvas.UP:{ if(--selected<0){ selected= selected+4; } // repaint(); break; } default: break; } repaint(); serviceRepaints(); } private void printLabel(int selected) { System.out.println(b[selected]); } }