将 NSString 插入 NSBundle 的 pathForResource 中？

Question

这对impactdrawarray中的UIImageView进行动画处理：

if ( ((impact *) [impactarray objectAtIndex:iv]).animframe == 70){
   ((UIImageView *) [impactdrawarray objectAtIndex:iv]).image =
          [UIImage imageWithContentsOfFile:
                         [[NSBundle mainBundle] pathForResource:@"explosionA71"
                                                         ofType:@"png"]];
}
if ( ((impact *) [impactarray objectAtIndex:iv]).animframe == 71){
       ((UIImageView *) [impactdrawarray objectAtIndex:iv]).image =
                       [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] 
                                        pathForResource:@"explosionA72"
                                                 ofType:@"png"]];
}

没有出现任何内容：

NSString *myString2 =
           [NSString stringWithFormat:@"A%d",
                     ((impact *) [impactarray objectAtIndex:iv]).animframe;

((UIImageView *) [impactdrawarray objectAtIndex:iv]).image =
                    [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] 
                                     pathForResource:(@"explosion%d", myString2)
                                              ofType:@"png"]];

我使用NSString的参考（示例）

NSString *myString23 = [NSString stringWithFormat:@"$%d", money];
moneylabel.text = myString23;

如何在文件名中使用变量？ 有没有办法通过索引加载资源文件夹中的图像？ 像imageByIndex:currentanimationframe之类的东西？ 我在 UIImage 文档中没有看到任何内容。

回复评论：

   NSString *myString2 = [NSString stringWithFormat:@"A%d", ((impact *) [impactarray objectAtIndex:iv]).animframe];
  ((UIImageView *) [impactdrawarray objectAtIndex:iv]).image = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:[NSString stringWithFormat:@"explosion%d", myString2] ofType:@"png"]];

并且

                NSString *imagename = [NSString stringWithFormat:@"A%d", ((impact *) [impactarray objectAtIndex:iv]).animframe];
                UIImage *myImage = [UIImage imageNamed:imagename];

                ((UIImageView *) [impactdrawarray objectAtIndex:iv]).image = myImage;

都编译并运行，但图像不显示。

Answer 1

使用 +stringWithFormat:，就像您的示例中一样：

[[NSBundle mainBundle] pathForResource:[NSString stringWithFormat:@"explosion%d", myString2] ofType:@"png"];

Answer 2

NSString* imageName = [self dynamicallyCalculateImageNameUsingCrazyMath];
UIImage* myImage = [UIImage imageNamed:imageName];