SPQuery query = new SPQuery();
query.Query = @"<Where>
<And>
<And>
<Eq>
<FieldRef Name='Over_x0020_Due' />
<Value Type='Choice'>ture</Value>
</Eq>
<Eq>
<FieldRef Name='Responsible' />
<Value Type='User'>" + ResName + @"</Value>
</Eq>
</And>
<Or>
<Eq>
<FieldRef Name='Device_x0020_Status' />
<Value Type='Choice'>在用Active</Value>
</Eq>
<Eq>
<FieldRef Name='Device_x0020_Status' />
<Value Type='Choice'>限用Limited</Value>
</Eq>
</Or>
</And>
</Where>";
query.ViewAttributes = "Scope=\"RecursiveAll\""; //可查询子文件夹里边的内容