parameters validation by custom attributes in c#

Question

Hello friend,

 

   I try to use the attribute to verify the parameters of the client.

  Now, how to use the interface injection to verify?

 

public interface ICheckParameter{

void Check(object objValue, string parameterName);

}

[AttributeUsage(AttributeTargets.Parameter)]

public class CheckIsNullOrEmptyAttribute : Attribute,ICheckParameter{

public CheckIsNullOrEmptyAttribute(){}

public void Check(object objValue,string parameterName){

if (objValue == null) throw new ArgumentNullException(parameterName);

}

}

[AttributeUsage(AttributeTargets.Parameter)]

public class CheckLengthAttribute : Attribute,ICheckParameter {

private int _minValue;

private int _maxValue;

public CheckLengthAttribute(int minValue,int maxValue){

this._minValue=minValue;

this._maxValue=maxValue;

}

public void Check(object objValue, string parameterName){

if (objValue == null) throw new ArgumentNullException(parameterName, "The object can't be null.");

int len = objValue.ToString().Length;

if (len<this._minValue||len>this._maxValue)

throw new ArgumentOutOfRangeException(parameterName,

string.Format("The value length must be between {0} and {1}",

this._minValue,this._maxValue));

}

}

public interface ICheckPower{

void CheckPower([CheckIsNullOrEmpty]string uName, [CheckLength(6, 10)]string pwd);

}

public class LoginClass : ICheckPower {

public LoginClass() { }

public void CheckPower(string uName, string pwd) {

try{

Console.WriteLine("Pass...\n");

}

catch (Exception error)

{

Console.WriteLine("An Error:{0}\n",error.Message);

}

}

}

class Program {

static void Main(string[] args){

LoginClass lc = new LoginClass();

lc.CheckPower(null, "123456");

lc.CheckPower("Test", "123");

Console.ReadKey(true);

}

}

 

 

Thank.  :)