xcode 如何查看字符串是否包含子字符串（objective-c）
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/8549898/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
how to see if a string contains a substring (objective-c)
提问by user973985
I want to see if a string, which is a title of a post on the apple rss news feed contains a substring, e.g. "Steve" or "Jobs". I organized the posts into a uitableview.
我想查看一个字符串（Apple RSS 新闻提要上的帖子标题）是否包含子字符串，例如“Steve”或“Jobs”。我将帖子组织成一个 uitableview。
So there WAS a post which had Steve or Jobs in its title so I used this to check:
所以有一篇文章的标题是史蒂夫或乔布斯，所以我用它来检查：
if ([[entry title] localizedCaseInsensitiveCompare:@"Steve"] == NSOrderedSame || [[entry title] localizedCaseInsensitiveCompare: @"Jobs"] == NSOrderedSame) {
NSLog(@"Comparism of Steve Jobs");
cell.imageView.image = [UIImage imageNamed:@"steve.png"];
}
But it was never called, entry is an RSSItem class which contains the title - the entry and its title is not my problem, I have checked. My comparism is the problem. How do i compare
但它从未被调用过，条目是一个包含标题的 RSSItem 类 - 条目及其标题不是我的问题，我已经检查过了。我的比较是问题所在。我如何比较
UPDATE!
更新！
Ok here is the code:
好的，这是代码：
NSRange range = [[[cell textLabel] text] rangeOfString:@"Steve" options:NSCaseInsensitiveSearch];
if (range.location != NSNotFound)
{
cell.imageView.image = [UIImage imageNamed:@"steve.png"];
}
I have tried it other peoples way also but SAME RESULT:
我也尝试过其他人的方式，但结果相同：
some cells have their imageView as steve.png even though their title doesnt contain steve jobs. Weird??? I scroll down and when I go back up all the dequeued cells which are reallocated and initialized have the steve jobs picture. At starting when i open the app some cells which don't have steve in their title DO HAVE THE IMAGE, and then the above happens.
一些单元格的 imageView 为 steve.png，即使它们的标题不包含 steve jobs。奇怪的？？？我向下滚动，当我返回所有重新分配和初始化的出列单元格时，会显示史蒂夫·乔布斯的图片。在开始时，当我打开应用程序时，一些标题中没有史蒂夫的单元格确实有图像，然后就会发生上述情况。
My surrounding code IF NEEDED:
如果需要，我的周围代码：
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView
dequeueReusableCellWithIdentifier:@"UITableViewCell"];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:@"UITableViewCell"]
autorelease];
}
tableView.autoresizingMask = 5;
tableView.autoresizesSubviews = YES;
cell.autoresizingMask = 5;
cell.frame = CGRectMake(cell.frame.origin.x, cell.frame.origin.y, 20, 20);
RSSItem *item = [[channel items] objectAtIndex:[indexPath row]];
[[cell textLabel] setText:[item title]];
NSMutableString *string = [[NSMutableString alloc] initWithString:[[cell textLabel] text]];
if (string.length > 46) {
cell.textLabel.numberOfLines = 2;
UILineBreakMode lineBreak = UILineBreakModeClip;
cell.textLabel.lineBreakMode = lineBreak;
}
[string release];
tableView.backgroundColor = [UIColor darkGrayColor];
cell.textLabel.font = [UIFont fontWithName:@"Arial Rounded MT Bold" size: 12.0];
cell.backgroundColor = [UIColor whiteColor];
NSRange range = [[[cell textLabel] text] rangeOfString:@"Steve" options:NSCaseInsensitiveSearch];
if (range.location != NSNotFound)
{
cell.imageView.image = [UIImage imageNamed:@"steve.png"];
}
return cell;
}
采纳答案by Hot Licks
"then when i scroll back up all the recycled cells have the steve jobs image"
“然后当我向上滚动时，所有回收的单元格都有史蒂夫·乔布斯的图像”
That's because you're not resetting the image in the recycled cells. (Try adding
那是因为您没有重置回收单元中的图像。（尝试添加
else {
cell.imageView.image = nil;
}
at an appropriate place.)
在适当的地方。）
回答by Josh Rosen
NSString-rangeOfString returns an NSRange, which can be checked for the "not found" case.
NSString-rangeOfString 返回一个 NSRange，可以检查“未找到”的情况。
if ([@"Some awesome string." rangeOfString:@"awesome"].location != NSNotFound)
{
// awesome is in 'Some awesome string.'
}
else
{
// awesome is not in 'Some awesome string.'
}
回答by Hot Licks
You're comparing the entire string, and "Steve Jobs" won't match either "Steve" or "Jobs". You probably want to use rangeOfString:@"Steve" options:NSCaseInsensitiveSearch, or some such.
您正在比较整个字符串，“史蒂夫乔布斯”不会匹配“史蒂夫”或“乔布斯”。您可能想使用rangeOfString:@"Steve" options:NSCaseInsensitiveSearch，或一些类似的。
回答by Fatima Arshad
If you are on iOS8 you can do this now as:
如果您使用的是 iOS8，您现在可以这样做：
NSString *stringToSearch = @"Steve";
if ([stringToSearch containsString:@"Steve"])
{
NSLog(@"String contains Steve!!!");
}
else
{
NSLog(@"String does not contain Steve!!!");
}
