轉載:https://p-blog.csdn.net/images/p_blog_csdn_net/pjw100/EntryImages/20091123/lwuit_0002.jpg
當我們加載某一個Form頁面時,如果這個頁面內容較多,加載需要一定的時間,那我們就希望做一個等待的畫面,比如"某某正在加載,請等待...",在這個畫面中以動態效果來說爲最好,用戶也知道需要等待很短的時間。我做等待界面有兩種方法:首先是方法一,這種方法屬於文字等待,就是在界面上畫一串文字,"..."是以動態的形式顯示,代碼如下:
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
import com.sun.lwuit.Font;
import com.sun.lwuit.Form;
import com.sun.lwuit.Graphics;
import com.sun.lwuit.Image;
import com.sun.lwuit.Label;
import com.sun.lwuit.layouts.BorderLayout;
import java.io.IOException;
import java.util.Random;
import java.util.Timer;
import java.util.TimerTask;
/**
*
* @author Administrator
*/
public class TextLoading extends Form implements Runnable {
private Timer timer = new Timer();
private long displayTime = 1000;
private StringBuffer loading = new StringBuffer("Saleslion is loading");
public TextLoading() {
Thread t = new Thread(this);
t.start();
this.setLayout(new BorderLayout());
this.show();
}
public void paint(Graphics g) {
try {
Image wait = Image.createImage("/logo.png");
//繪製logo
g.drawImage(wait, (getWidth() - wait.getWidth()) / 2, (getHeight() - wait.getHeight()- 70) / 2);
g.setColor(0xffffff);
Font fnt = Font.createSystemFont(Font.FACE_PROPORTIONAL, Font.STYLE_PLAIN, Font.SIZE_LARGE);
g.setFont(fnt);
int wordWidth = fnt.stringWidth("Saleslion is loading...");
//繪製等待字符串
g.drawString(loading.toString(), (getWidth() - wordWidth) / 2, (getHeight() + wait.getHeight() -60) / 2);
} catch (IOException ex) {
ex.printStackTrace();
}
}
private void disappear() {
timer.cancel();
try {
new LoginForm();
} catch (IOException ex) {
ex.printStackTrace();
}
}
//調用TimerTask,時間到了後,調用disappear(),當前畫面消失,跳至另一個Form
protected void showNotify() {
timer.schedule(new TimerTask() {
public void run() {
disappear();
}
}, displayTime);
}
//設置字符串
public void setLoading() {
if (loading.toString().indexOf("...") > 0) {
loading.delete(loading.length() - 3, loading.length());
}
}
public void run() {
while (true) {
try {
//調用線程來繪製字符串
Thread.sleep(500);
setLoading();
loading.append(".");
} catch (Exception e) {
}
repaint();
}
}
}
以上代碼比較簡單,也不做多的解釋,它是基於Form的。
但是這並不是我想要的效果,假如在一個九宮格中,我點擊某一格時,我希望出現一個loading畫面顯示正在加載這一項,但是以遮罩的形式顯示(就像web開發裏面彈出的遮罩層對話框一樣),也就是說,彈出loading時,我仍然能夠見到原來的九宮格畫面。我要的效果如下圖:
如果要實現這種形式的loading畫面,只有通過Dialog類來實現。
製作這種Dialog有幾個小問題需要解決:
1.lwuit中如何顯示gif動畫
2.Dialog全透明
3.Dialog自動釋放
一直沒有實現這個效果,關鍵是問題1,但是在上一節 我已經解決了,下面就看關鍵代碼,代碼仍然很簡單:
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package com.thinkrace.UCHome.ui;
import com.sun.lwuit.Dialog;
import com.sun.lwuit.Display;
import com.sun.lwuit.Image;
import com.sun.lwuit.Label;
import com.sun.lwuit.util.Resources;
import java.io.IOException;
/**
*
* @author Administrator
*/
public class LoadingDialog extends Dialog {
public LoadingDialog() {
try {
//設置對話框全透明
for (int i = 0; i < getComponentCount(); i++) {
getComponentAt(i).getStyle().setBgTransparency(0);
}
Image icon = Resources.open("/resources.res").getImage("loading.gif");
Label l = new Label(icon);
l.getStyle().setBgTransparency(0);
addComponent(l);
int w = Display.getInstance().getDisplayWidth();
int h = Display.getInstance().getDisplayHeight();
int top = (h - icon.getHeight()) / 2 - 10;
int left = (w - icon.getWidth()) / 2 - 10;
setTimeout(3000);
show(top,top,left,left,false);
} catch (IOException ex) {
ex.printStackTrace();
}
}
}