我有一个包含许多测验项目的plist是使用arc4random()随机抽取的,我想在显示后删除每个项目以便不重复任何问题,我尝试使用[thisArray removeObjectAtIndex:r];
,但项目仍然显示。有什么想法吗?
NSString *path = [[NSBundle mainBundle] pathForResource:@"initialquestions" ofType:@"plist"];
NSFileManager *fileManager = [NSFileManager defaultManager];
if ([fileManager fileExistsAtPath:path]) {
NSLog(@"The file exists");
}
else {
NSLog(@"The file does not exist");
}
NSMutableArray *thisArray = [[NSMutableArray alloc] initWithContentsOfFile:path];
NSLog(@"The array count: %i", [thisArray count]);
for (int i = 0; i < [thisArray count]; i++) {
id obj;
int r = arc4random() % [thisArray count];
if(r<[thisArray count]){
obj=[thisArray objectAtIndex:r];
}
else{
//error message
}
QuestionTitle.text = [[thisArray objectAtIndex:r] objectForKey:@"QuestionTitle"];
[btnA setTitle:[[thisArray objectAtIndex:r] objectForKey:@"A"] forState:UIControlStateNormal];
[btnB setTitle:[[thisArray objectAtIndex:r] objectForKey:@"B"] forState:UIControlStateNormal];
[btnC setTitle:[[thisArray objectAtIndex:r] objectForKey:@"C"] forState:UIControlStateNormal];
[thisArray removeObjectAtIndex:r];
}
答案 0 :(得分:1)
当你的阵列缩小时,你需要一个反向循环:
for (int i = [thisArray count]-1; i > -1 ; i--) {
....
}