NSString *path = [[NSBundle mainBundle] pathForResource:@"NewsStory1" ofType:@"txt"];
NSString *content = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];

有关NSString，请参阅Apple的iOS API文档，特别是“从文件创建和初始化字符串”一节

在斯威夫特

let path = NSBundle.mainBundle().pathForResource("home", ofType: "html")

    do {
        let content = try String(contentsOfFile:path!, encoding: NSUTF8StringEncoding)} catch _ as NSError {}

非常简单

只需创建一个方法，如下所示

- (void)customStringFromFile
{
    NSString* filePath = [[NSBundle mainBundle] pathForResource:@"NewsStory1" ofType:@"txt"];
    NSString *stringContent = [NSString stringWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:nil];
    NSLog(@"\n Result = %@",stringContent);
}

在Swift 4中，可以这样做：

let path = Bundle.main.path(forResource: "test_data", ofType: "txt")
if let path = path {
    do {
        let content = try String(contentsOfFile: path, encoding: String.Encoding.utf8)
        print(content)
    } catch let error as NSError {
        print("Error occured: \(error.localizedDescription)")
    }
} else {
    print("Path not available")
}

Objective-C的另一个简单方法是：

NSError *error = nil;
NSString *string = [[NSString alloc] initWithContentsOfFile: @"<paht/to/file>"
                     enconding:NSUTF8StringEncoding
                     error: &error];