Question

我知道我可以这样做：

switch (imageNumber) {
     case 1: image1.image = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"imageName" ofType:@"jpg"]]; break;
     case 2: image2.image = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"imageName" ofType:@"jpg"]]; break;
     case 3: image3.image = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"imageName" ofType:@"jpg"]]; break;
     case 4: image4.image = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"imageName" ofType:@"jpg"]]; break;
}

我想在我的代码中更有效率，所以我想知道是否有办法这样做：

switch (imageNumber) {
     case 1: //somehow set image1 as the imageView I want used
     case 2: //somehow set image2 as the imageView I want used
     case 3: //somehow set image3 as the imageView I want used
     case 4: //somehow set image4 as the imageView I want used
}
imageWhicheverWasSet.image = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"imageName" ofType:@"jpg"]];

提前感谢您的帮助！

Answer 1

您自己粘贴的第二个代码段实际上非常接近解决方案。您只需将UIImageView *imageToChange;设置为实例变量，然后执行：

imageToChange.image = nil; // will clear the image on last selected image view
// if you don't need that, just remove that line and leave others
switch (imageNumber) {
    case 1: imageToChange = image1; break;
    case 2: imageToChange = image2; break;
    case 3: imageToChange = image3; break;
    case 4: imageToChange = image4; break;
}
imageToChange.image = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"imageName" ofType:@"jpg"]];

Answer 2

您可以将UIImageViews放在一个数组中，然后使用索引选择正确的索引。除非你有更多的UIImageViews要处理，否则不确定这会有用。

NSArray* imageViews = [NSArray arrayWithObjects: image1, image2, image3, image4, nil];

UIImageView* theImage = [imageViews objectAtIndex: imageNumber-1];
UIImage* theImage = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"imageName" ofType:@"jpg"]];

您需要验证imageNumber以确保它在范围内。

Answer 3

怎么样 -

UIImage* theImage = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"imageName" ofType:@"jpg"]];
switch ...
    case 1:image1.image = theImage; break;
    case 2:...

你也可以 -

MyImageType* tempImageObj = nil;
switch ... {
    case 1:tempImageObj = &image1; break; // Or just image1, if ".image" is a property, not a field
    case 2:...
}
tempImageObj ->image = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"imageName" ofType:@"jpg"]];  // Or "." instead of "->" if property.

Answer 4

另一种方法是使用数组

UIImageView *iv[] = {
  image1,
  image2,
  image3,
  image4,
};
if (imageNumber>=0 && imageNumber<4) 
  iv[imageNumber].image = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle]
                                           pathForResource:@"imageName" 
                                                    ofType:@"jpg"]]

UIImageView的占位符变量

4 个答案: