objective-c - 从 iPhone 中的 UTF8String 编码中检索数据

Question

我正在使用以下代码将文本保存在 serverDb 中。它可以包含从空格到冒号的任何字符。

queryString = [queryString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

可以说我发送了字符串"I Can't come"。在服务器中，它将存储为I can\'t come.

在检索如何删除此类反斜杠和其他字符时。

Answer 1

// While storing       
NSString *queryString =@"I can't come";
queryString = [queryString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSLog(@"%@",queryString);

// While retrieving
queryString = [queryString stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSLog(@"%@",queryString);

Answer 2

如果您想处理所有输入，我建议您对您在查询字符串中发送的任何内容进行 url 编码和解码：

+ (NSString*)urlEncode:(NSString*)rawString {
    NSMutableString *escaped = [[rawString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding] mutableCopy];   
    [escaped replaceOccurrencesOfString:@"$" withString:@"%24" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"&" withString:@"%26" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"+" withString:@"%2B" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"," withString:@"%2C" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"/" withString:@"%2F" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@":" withString:@"%3A" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@";" withString:@"%3B" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"=" withString:@"%3D" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"?" withString:@"%3F" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"@" withString:@"%40" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@" " withString:@"%20" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"\t" withString:@"%09" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"#" withString:@"%23" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"<" withString:@"%3C" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@">" withString:@"%3E" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"\"" withString:@"%22" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"\n" withString:@"%0A" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];

    return escaped;
}

+ (NSString *)urlDecode:(NSString *)rawString {
    NSMutableString *escaped =  [rawString mutableCopy];
    [escaped replaceOccurrencesOfString:@"%24" withString:@"$" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"%26" withString:@"&" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"%2B" withString:@"+" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"%2C" withString:@"," options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"%2F" withString:@"/" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"%3A" withString:@":" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"%3B" withString:@";" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"%3D" withString:@"=" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"%3F" withString:@"?" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"%20" withString:@" " options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"%40" withString:@"@" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"%09" withString:@"\t" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"%23" withString:@"#" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"%3C" withString:@"<" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"%3E" withString:@">" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"%22" withString:@"\"" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];
    [escaped replaceOccurrencesOfString:@"%0A" withString:@"\n" options:NSCaseInsensitiveSearch range:NSMakeRange(0, [escaped length])];

    return escaped;
}

Answer 3

这很简单，您只需使用该- (NSString *)stringByReplacingOccurrencesOfString:(NSString *)target withString:(NSString *)replacement方法即可。这是您的一小段代码：

NSString *str = your server string with backslashes
NSString *stringWithoutBackSlashes = [str stringByReplacingOccurrencesOfString:@"\" withString:@""];