在asp.net core中使用带有对象参数值的GetAsync方法，需要通过构建HttpClient来实现。具体实现步骤如下：

1. 创建一个HttpClient对象：

HttpClient client = new HttpClient();

2. 定义要发送的请求的Uri和参数对象：

Uri uri = new Uri("http://example.com/api"); MyObject myObject = new MyObject { Id = 1, Name = "example" };

3. 使用Newtonsoft.Json将参数对象序列化成JSON字符串：

string json = JsonConvert.SerializeObject(myObject);

4. 创建HttpContent对象，并将JSON字符串作为Content：

HttpContent httpContent = new StringContent(json, Encoding.UTF8, "application/json");

5. 将httpContent作为GetAsync方法的参数发送请求：

HttpResponseMessage response = await client.GetAsync(uri + "?param=" + httpContent);

6. 接收返回的结果：

string result = await response.Content.ReadAsStringAsync();

完整代码示例如下：

using Newtonsoft.Json; using System; using System.Net.Http; using System.Text; using System.Threading.Tasks;

public class MyObject { public int Id { get; set; } public string Name { get; set; } }

public class Program { static async Task Main() { HttpClient client = new HttpClient(); Uri uri = new Uri("http://example.com/api"); MyObject myObject = new MyObject { Id = 1, Name = "example" }; string json = JsonConvert.SerializeObject(myObject); HttpContent httpContent = new StringContent(json, Encoding.UTF8, "application/json"); HttpResponseMessage response = await client.GetAsync(uri + "?param=" + httpContent); string result = await response.Content.ReadAsStringAsync();

    // do something with result
}

}

注意：在使用GetAsync方法时如果携带的参数值较大，也可以考虑使用POST方法发送请求。