Question

了解如何从以下链接中检索iOS设备中的最后一张照片

How to retrieve the most recent photo from Camera Roll on iOS?

但是我想要检索最后20张照片，因为我不想减慢性能，让用户以相反的顺序查看他们的照片

我试过

long index = group.numberOfAssets - 2;

并结束此错误

由于未捕获的异常'NSRangeException'而终止应用程序，原因：'*** - [NSIndexSet initWithIndexesInRange：]：范围{4294967294,1}超过NSNotFound的最大索引值 - 1'

任何人都可以在这里帮忙吗？感谢

ALAssetsLibrary * library = [[ALAssetsLibrary alloc] init];

[library enumerateGroupsWithTypes:ALAssetsGroupSavedPhotos usingBlock:^(ALAssetsGroup *group, BOOL *stop) {

    [group setAssetsFilter:[ALAssetsFilter allPhotos]];

    ***long index              = group.numberOfAssets - 2;***
    [group enumerateAssetsAtIndexes:[NSIndexSet indexSetWithIndex:index]
                            options:0
                         usingBlock:^(ALAsset *alAsset, NSUInteger index, BOOL *innerStop)

Answer 1

可能是你以错误的方式列举。 This code gets the last image

    ALAssetsGroup* group = [groups lastObject]; // get all assets groups, i think you know how to get them.
    [group enumerateAssetsAtIndexes:[NSIndexSet indexSetWithIndex:(group.numberOfAssets - 1)] options:NSEnumerationConcurrent usingBlock:^(ALAsset *result, NSUInteger index, BOOL *stop)
     {
         if(result) {
                  // result is your needed last asset
             }

     }];

从iPhone检索最后几张照片

1 个答案: