要正确地对参数进行 URL 编码,您需要将每个名称和值转换为 UTF-8,然后分别对每个名称和值进行 URL 编码,然后使用 '=' 将名称与值连接起来,并使用 '&' 连接名称-值对。
我通常发现将所有参数放在 NSDictionary 中更容易,然后从字典中构建查询字符串。这是我用来执行此操作的类别:
// file NSDictionary+UrlEncoding.h
#import <Cocoa/Cocoa.h>
@interface NSDictionary (UrlEncoding)
-(NSString*) urlEncodedString;
@end
// file NSDictionary+UrlEncoding.m
#import "NSDictionary+UrlEncoding.h"
// private helper function to convert any object to its string representation
static NSString *toString(id object) {
return [NSString stringWithFormat: @"%@", object];
}
// private helper function to convert string to UTF-8 and URL encode it
static NSString *urlEncode(id object) {
NSString *string = toString(object);
return [string stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding];
}
@implementation NSDictionary (UrlEncoding)
-(NSString*) urlEncodedString {
NSMutableArray *parts = [NSMutableArray array];
for (id key in self) {
id value = [self objectForKey: key];
NSString *part = [NSString stringWithFormat: @"%@=%@",
urlEncode(key), urlEncode(value)];
[parts addObject: part];
}
return [parts componentsJoinedByString: @"&"];
}
@end
该方法构建一个名称-值对数组,parts
通过 URL 对每个键和值进行编码调用,然后用“=”将它们连接在一起。然后parts
数组中的部分用 '&' 字符连接在一起。
所以对于你的例子:
#import "NSDictionary+UrlEncoding.h"
// ...
NSMutableDictionary *parameters = [NSMutableDictionary dictionary];
[parameters setValue: @"t" forKey: @"client"];
[parameters setValue: @"auto" forKey: @"sl"];
[parameters setValue: destinationLanguage forKey: @"tl"];
[parameters setValue: text forKey: @"text"];
NSString *urlString = [@"/translate_a/t?" stringByAppendingString: [parameters urlEncodedString]];