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[英]How can you instantiate an object with a string and send a parameter in C#?
[英]How can I send an array as a parameter of a query string in c#?
我正在嘗試使用本地開發的Web API來檢索一些數據。 該文檔全部用PHP編寫。 我正在看的示例是這樣的:
$params = array(
'id' => 1
,'data' => array(
,'email' => 'example@hasoffers.com'
)
$url = "www.someapi.com/api?" . http_build_query( $params );
我正在使用C#WebClient類,但無法弄清楚如何序列化data參數:
WebClient wc = new WebClient();
wc.QueryString["id"] = "1";
wc.QueryString["data"] = // I have no idea.
string json = wc.DownloadString(apiUrl);
我嘗試了一些變體:
wc.QueryString["data"] = "email=test@stackoverflow.com";
wc.QueryString["data"] = Uri.EscapeDataString("data[email]=test@stackoverflow.com");
wc.QueryString["data"] = Uri.EscapeDataString("email[0]=test@stackoverflow.com");
wc.QueryString["data"] = Uri.EscapeDataString("email=test@stackoverflow.com");
當然,我在任何地方都沒有安裝PHP來查看http_build_query()實際返回的內容。
我終於弄明白了。 我想發布這個問題重新啟動了我的大腦。
這是有效的:
wc.QueryString["data[email]"] = "test@stackoverflow.com";
據我所知,沒有內置的功能可以做到這一點。 但是,您可以創建自己的類。
所以我做了:
/// <summary>
/// Helps up build a query string by converting an object into a set of named-values and making a
/// query string out of it.
/// </summary>
public class QueryStringBuilder
{
private readonly List<KeyValuePair<string, object>> _keyValuePairs
= new List<KeyValuePair<string, object>>();
/// <summary> Builds the query string from the given instance. </summary>
public static string BuildQueryString(object queryData, string argSeperator = "&")
{
var encoder = new QueryStringBuilder();
encoder.AddEntry(null, queryData, allowObjects: true);
return encoder.GetUriString(argSeperator);
}
/// <summary>
/// Convert the key-value pairs that we've collected into an actual query string.
/// </summary>
private string GetUriString(string argSeperator)
{
return String.Join(argSeperator,
_keyValuePairs.Select(kvp =>
{
var key = Uri.EscapeDataString(kvp.Key);
var value = Uri.EscapeDataString(kvp.Value.ToString());
return $"{key}={value}";
}));
}
/// <summary> Adds a single entry to the collection. </summary>
/// <param name="prefix"> The prefix to use when generating the key of the entry. Can be null. </param>
/// <param name="instance"> The instance to add.
///
/// - If the instance is a dictionary, the entries determine the key and values.
/// - If the instance is a collection, the keys will be the index of the entries, and the value
/// will be each item in the collection.
/// - If allowObjects is true, then the object's properties' names will be the keys, and the
/// values of the properties will be the values.
/// - Otherwise the instance is added with the given prefix to the collection of items. </param>
/// <param name="allowObjects"> true to add the properties of the given instance (if the object is
/// not a collection or dictionary), false to add the object as a key-value pair. </param>
private void AddEntry(string prefix, object instance, bool allowObjects)
{
var dictionary = instance as IDictionary;
var collection = instance as ICollection;
if (dictionary != null)
{
Add(prefix, GetDictionaryAdapter(dictionary));
}
else if (collection != null)
{
Add(prefix, GetArrayAdapter(collection));
}
else if (allowObjects)
{
Add(prefix, GetObjectAdapter(instance));
}
else
{
_keyValuePairs.Add(new KeyValuePair<string, object>(prefix, instance));
}
}
/// <summary> Adds the given collection of entries. </summary>
private void Add(string prefix, IEnumerable<Entry> datas)
{
foreach (var item in datas)
{
var newPrefix = String.IsNullOrEmpty(prefix)
? item.Key
: $"{prefix}[{item.Key}]";
AddEntry(newPrefix, item.Value, allowObjects: false);
}
}
private struct Entry
{
public string Key;
public object Value;
}
/// <summary>
/// Returns a collection of entries that represent the properties on the object.
/// </summary>
private IEnumerable<Entry> GetObjectAdapter(object data)
{
var properties = data.GetType().GetProperties();
foreach (var property in properties)
{
yield return new Entry()
{
Key = property.Name,
Value = property.GetValue(data)
};
}
}
/// <summary>
/// Returns a collection of entries that represent items in the collection.
/// </summary>
private IEnumerable<Entry> GetArrayAdapter(ICollection collection)
{
int i = 0;
foreach (var item in collection)
{
yield return new Entry()
{
Key = i.ToString(),
Value = item,
};
i++;
}
}
/// <summary>
/// Returns a collection of entries that represent items in the dictionary.
/// </summary>
private IEnumerable<Entry> GetDictionaryAdapter(IDictionary collection)
{
foreach (DictionaryEntry item in collection)
{
yield return new Entry()
{
Key = item.Key.ToString(),
Value = item.Value,
};
}
}
}
像這樣:
// Age=19&Name=John%26Doe&Values%5B0%5D=1&Values%5B1%5D=2&Values%5B2%5D%5Bkey1%5D=value1&Values%5B2%5D%5Bkey2%5D=value2
QueryStringBuilder.BuildQueryString(new
{
Age = 19,
Name = "John&Doe",
Values = new object[]
{
1,
2,
new Dictionary<string, string>()
{
{ "key1", "value1" },
{ "key2", "value2" },
}
},
});
// 0=1&1=2&2%5B0%5D=one&2%5B1%5D=two&2%5B2%5D=three&3%5Bkey1%5D=value1&3%5Bkey2%5D=value2
QueryStringBuilder.BuildQueryString(new object[]
{
1,
2,
new object[] { "one", "two", "three" },
new Dictionary<string, string>()
{
{ "key1", "value1" },
{ "key2", "value2" },
}
}
);
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