iOS 判断内容是否是中文，两种实现

#import <Foundation/Foundation.h>

@interface NSString (Valid)

- (BOOL)isChinese;

@end

#import "NSString+Valid.h"

@implementation NSString (Valid)

- (BOOL)isChinese
{
    NSString *match = @"(^[\u4e00-\u9fa5]+$)";
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF matches %@", match];
    return [predicate evaluateWithObject:self];
}

@end

if ([self.usernameTextField.text isChinese]) {
      //  do      
}

- (BOOL)isChinese:(NSString *)str
{
    NSString *match = @"(^[\u4e00-\u9fa5]+$)";
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF matches %@", match];
    return [predicate evaluateWithObject:str];
}