public void WiteToStringWithReferenceTest()
{
var p = new People {
Name = "fireasy"
};
Expression <Func <Work, bool> > expression = (s) => s.People.Name == p.Name;
Console.WriteLine(ExpressionWriter.WriteToString(expression));
}
public void WiteToStringWithConstantTest()
{
var str = "fireasy";
var p = new People {
Age = 34
};
Expression <Func <People, bool> > expression = (s) => s.Name == str && s.Age == p.Age;
Console.WriteLine(ExpressionWriter.WriteToString(expression));
}
/// <summary>
/// 通过表达式计算出对应的缓存键。
/// </summary>
/// <param name="expression"></param>
/// <returns></returns>
private static string GetKey(Expression expression)
{
var evalExp = PartialEvaluator.Eval(expression, TranslateProviderBase.EvaluatedLocallyFunc);
var cacheKey = ExpressionWriter.WriteToString(evalExp);
//使用md5进行hash编码
var md5 = new MD5CryptoServiceProvider();
byte[] data = md5.ComputeHash(Encoding.Unicode.GetBytes(cacheKey));
return("$." + Convert.ToBase64String(data, Base64FormattingOptions.None));
}
/// <summary>
/// 通过表达式计算出对应的缓存键。
/// </summary>
/// <param name="expression">作为 Key 的 Lambda 表达式。</param>
/// <param name="prefix">用于区分缓存的前缀。</param>
/// <returns></returns>
public string Generate(Expression expression, params string[] prefix)
{
var evalExp = PartialEvaluator.Eval(expression, TranslateProviderBase.EvaluatedLocallyFunc);
var cacheKey = ExpressionWriter.WriteToString(evalExp);
//使用md5进行hash编码
var md5 = new MD5CryptoServiceProvider();
var data = md5.ComputeHash(Encoding.Unicode.GetBytes(cacheKey));
var sb = new StringBuilder();
foreach (var p in prefix)
{
if (!string.IsNullOrEmpty(p))
{
sb.AppendFormat("{0}:", p);
}
}
sb.Append(data.ToHex(true));
return(sb.ToString());
}
public void WiteToStringWithSubqueryTest()
{
Expression <Func <People, bool> > expression = (s) => s.Works.Count(t => t.Company == "aa") > 0;
Console.WriteLine(ExpressionWriter.WriteToString(expression));
}
public void WiteToStringWithLengthTest()
{
Expression <Func <People, bool> > expression = (s) => s.Name.Length == 4;
Console.WriteLine(ExpressionWriter.WriteToString(expression));
}
public void WriteToStringTest()
{
Expression <Func <People, bool> > expression = (s) => s.Age == 12;
Console.WriteLine(ExpressionWriter.WriteToString(expression));
}
