学步园

//引用DXErrorProvider命名空间
using DevExpress.XtraEditors.DXErrorProvider;

//设置控件的验证规则
//继承ValidationRule类
public class StringEmptyValidation : ValidationRule
{
    public override bool Validate(Control control, object value)
    {
        string str = (string)value;
        bool res = false;
        if (str != null && str.Length > 0)
        {
            res = true;
        }
        return res;
    }
}

StringEmptyValidation emptyValidation = new StringEmptyValidation();
//设置验证提示文字
emptyValidation.ErrorText = "Please enter a valid user name";
//设置验证提示图标
emptyValidation.ErrorType = ErrorType.Critical;
//设置验证类型，自动还是手动
dxValidationProvider1.ValidationMode = ValidationMode.Manual;
//设置验证控件,验证图标位置
dxValidationProvider1.SetIconAlignment(this.tbx_Userid, ErrorIconAlignment.MiddleRight);
//设置验证控件所使用的验证规则
dxValidationProvider1.SetValidationRule(this.tbx_Userid, emptyValidation);