我正在尝试创建一个加载52张卡片的小程序，将它们随机播放（使用随机数生成器），然后以两行五行显示卡片的前10张卡片。这是我的代码，但它似乎没有打印任何图像。
import java.applet.Applet;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Color;
public class cards extends Applet {
Image c1;
Image c2;
Image c3;
Image c4;
Image c5;
Image c6;
Image c7;
Image c8;
Image c9;
Image c10;
Image cj;
Image cq;
Image ck;
Image h1;
Image h2;
Image h3;
Image h4;
Image h5;
Image h6;
Image h7;
Image h8;
Image h9;
Image h10;
Image hj;
Image hq;
Image hk;
Image d1;
Image d2;
Image d3;
Image d4;
Image d5;
Image d6;
Image d7;
Image d8;
Image d9;
Image d10;
Image dj;
Image dq;
Image dk;
Image s1;
Image s2;
Image s3;
Image s4;
Image s5;
Image s6;
Image s7;
Image s8;
Image s9;
Image s10;
Image sj;
Image sq;
Image sk;
public void init(){
this.setBackground( Color.blue );
c1 = getImage ( getDocumentBase (), "cards/c1.gif" );
c2 = getImage ( getDocumentBase (), "cards/c2.gif" );
c3 = getImage ( getDocumentBase (), "cards/c3.gif" );
c4 = getImage ( getDocumentBase (), "cards/c4.gif" );
c5 = getImage ( getDocumentBase (), "cards/c5.gif" );
c6 = getImage ( getDocumentBase (), "cards/c6.gif" );
c7 = getImage ( getDocumentBase (), "cards/c7.gif" );
c8 = getImage ( getDocumentBase (), "cards/c8.gif" );
c9 = getImage ( getDocumentBase (), "cards/c9.gif" );
c10 = getImage ( getDocumentBase (), "cards/c10.gif" );
cj = getImage ( getDocumentBase (), "cards/cj.gif" );
cq = getImage ( getDocumentBase (), "cards/cq.gif" );
ck = getImage ( getDocumentBase (), "cards/ck.gif" );
h1 = getImage ( getDocumentBase (), "cards/h1.gif" );
h2 = getImage ( getDocumentBase (), "cards/h2.gif" );
h3 = getImage ( getDocumentBase (), "cards/h3.gif" );
h4 = getImage ( getDocumentBase (), "cards/h4.gif" );
h5 = getImage ( getDocumentBase (), "cards/h5.gif" );
h6 = getImage ( getDocumentBase (), "cards/h6.gif" );
h7 = getImage ( getDocumentBase (), "cards/h7.gif" );
h8 = getImage ( getDocumentBase (), "cards/h8.gif" );
h9 = getImage ( getDocumentBase (), "cards/h9.gif" );
h10 = getImage ( getDocumentBase (), "cards/h10.gif" );
hj = getImage ( getDocumentBase (), "cards/hj.gif" );
hq = getImage ( getDocumentBase (), "cards/hq.gif" );
hk = getImage ( getDocumentBase (), "cards/hk.gif" );
d1 = getImage ( getDocumentBase (), "cards/d1.gif" );
d2 = getImage ( getDocumentBase (), "cards/d2.gif" );
d3 = getImage ( getDocumentBase (), "cards/d3.gif" );
d4 = getImage ( getDocumentBase (), "cards/d4.gif" );
d5 = getImage ( getDocumentBase (), "cards/d5.gif" );
d6 = getImage ( getDocumentBase (), "cards/d6.gif" );
d7 = getImage ( getDocumentBase (), "cards/d7.gif" );
d8 = getImage ( getDocumentBase (), "cards/d8.gif" );
d9 = getImage ( getDocumentBase (), "cards/d9.gif" );
d10 = getImage ( getDocumentBase (), "cards/d10.gif" );
dj = getImage ( getDocumentBase (), "cards/dj.gif" );
dq = getImage ( getDocumentBase (), "cards/dq.gif" );
dk = getImage ( getDocumentBase (), "cards/dk.gif" );
s1 = getImage ( getDocumentBase (), "cards/s1.gif" );
s2 = getImage ( getDocumentBase (), "cards/s2.gif" );
s3 = getImage ( getDocumentBase (), "cards/s3.gif" );
s4 = getImage ( getDocumentBase (), "cards/s4.gif" );
s5 = getImage ( getDocumentBase (), "cards/s5.gif" );
s6 = getImage ( getDocumentBase (), "cards/s6.gif" );
s7 = getImage ( getDocumentBase (), "cards/s7.gif" );
s8 = getImage ( getDocumentBase (), "cards/s8.gif" );
s9 = getImage ( getDocumentBase (), "cards/s9.gif" );
s10 = getImage ( getDocumentBase (), "cards/s10.gif" );
sj = getImage ( getDocumentBase (), "cards/sj.gif" );
sq = getImage ( getDocumentBase (), "cards/sq.gif" );
sk = getImage ( getDocumentBase (), "cards/sk.gif" );
}
public void paint( Graphics screen ){
int x = 10;
int y = 10;
int x2 = 10;
int y2 = 110;
Image [] cards = new Image [ 52 ];
cards [ 0 ] = c1;
cards [ 1 ] = c2;
cards [ 2 ] = c3;
cards [ 3 ] = c4;
cards [ 4 ] = c5;
cards [ 5 ] = c6;
cards [ 6 ] = c7;
cards [ 7 ] = c8;
cards [ 8 ] = c9;
cards [ 9 ] = c10;
cards [ 10 ] = cj;
cards [ 11 ] = cq;
cards [ 12 ] = ck;
cards [ 13 ] = h1;
cards [ 14 ] = h2;
cards [ 15 ] = h3;
cards [ 16 ] = h4;
cards [ 17 ] = h5;
cards [ 18 ] = h6;
cards [ 19 ] = h7;
cards [ 20 ] = h8;
cards [ 21 ] = h9;
cards [ 22 ] = h10;
cards [ 23 ] = hj;
cards [ 24 ] = hq;
cards [ 25 ] = hk;
cards [ 26 ] = d1;
cards [ 27 ] = d2;
cards [ 28 ] = d3;
cards [ 29 ] = d4;
cards [ 30 ] = d5;
cards [ 31 ] = d6;
cards [ 32 ] = d7;
cards [ 33 ] = d8;
cards [ 34 ] = d9;
cards [ 35 ] = d10;
cards [ 36 ] = dj;
cards [ 37 ] = dq;
cards [ 38 ] = dk;
cards [ 39 ] = s1;
cards [ 40 ] = s2;
cards [ 41 ] = s3;
cards [ 42 ] = s4;
cards [ 43 ] = s5;
cards [ 44 ] = s6;
cards [ 45 ] = s7;
cards [ 46 ] = s8;
cards [ 47 ] = s9;
cards [ 48 ] = s10;
cards [ 49 ] = sj;
cards [ 50 ] = sq;
cards [ 51 ] = sk;
for (int i = 0; i < 4; i++){
screen.drawImage (cards[( int ) ( float ) Math.random () * 52 - 1], x, y, this);
x = x + 5;
}
for (int i = 0; i < 4; i++){
screen.drawImage (cards [( int ) ( float ) ( Math.random () ) * 52 - ( int ) ( 1 )], x2, y2, this);
x = x + 10;
}
}
}
答案 0 :(得分：2)
即使加载了图像，你的applet也会在第一个paint事件中死掉，因为随机化总是生成一个-1的卡片索引：
( int ) ( float ) Math.random () * 52 - 1
这始终为-1，因为在[0-1]之间生成随机数，并将其转换为整数，将其向下舍入为零。之后，你减去一个。它是一个无效的索引，你会得到一个例外。
将此随机化代码更改为常量0以检查加载是否正确完成。
如果可以的话，你应该在第一次将卡加载到阵列中。这样你就可以适当地洗牌。另外，尝试将卡片包装到某个类中，以后再用它会很方便。