Xamarin Firebase DeleteAsync

Question

我在Xamarin Android應用程序中從我的Firebase數據庫中刪除項目時遇到問題。

我得到一個400（錯誤請求）錯誤

刪除方法：

private async void RemovePost(string ActivityID) 
{ 
    var firebase = new FirebaseClient(FirebaseURL); 
    await firebase.Child("posts").Child(ActivityID).DeleteAsync(); 

    var intent = new Intent(mContext, typeof(MyProfileActivity)); 
    mContext.StartActivity(intent); 
} 

型號：

public class Post 
{ 
    public string ActivityID { get; set; } 

    public string OwnerID { get; set; } 

    public string ActivityTitle { get; set; } 

    public string ActivitySport { get; set; } 

    public DateTime ActivityDate { get; set; } 

    public DateTime ActivityTime { get; set; } 

    public string ActivityTown { get; set; } 

    public string ActivityAddress { get; set; } 

    public string ActivityPhone { get; set; } 

    public string ActivityEmail { get; set; } 

    public string ActivityDetails { get; set; } 
} 

火力地堡數據庫表：

注意活動我正在傳遞給RemovePost方法是「0」

Answer 1

那麼，爲什麼在第一個地方保存記錄到數據庫中，當你不使ActivityId的關鍵？

var post = new Post { 
    ActivityId = 0, 
    //...other properties populated 
} 

var record = await firebase 
    .Child("posts") 
    .Child(post.ActivityId) 
    .PostAsync(post)); 

var posts = await firebase 
    .Child("posts") 
    .OnceAsync<Post>(); 

foreach (var item in posts) { 
    Console.WriteLine($"{item.Key} post has id {item.Object.ActivityId}"); 
} 

await firebase.Child("posts").Child(post.ActivityID).DeleteAsync(); 

這樣，查詢記錄時，你可以在一個已知的關鍵

Answer 2

此：

await firebase.Child("posts").Child(ActivityID) 

將嘗試到ActivityID相匹配，你的情況是價值KiG7ju8CsDfGW3eSBIn

試着改變你的火力刪除節點的根打電話是這樣的：

await firebase.Child("posts").OrderBy("ActivityID").EqualTo(ActivityID).DeleteAsync(); 

更新

試試這個，這樣你可以調試。設置一箇中斷點並運行呼叫以查看結果。

//Get the record(s). Can be more than one if ActivityID value is repeated. 
var posts = await firebase 
    .Child("posts") 
    .OrderBy("ActivityID") 
    .EqualTo("0") 
    .OnceAsync<Post>(); 

// Select only the first one 
var firstPost = posts.FirstOrDefault(); 

// send to delete this 
await firebase 
    .Child("posts") 
    .Child(firstPost?.Key) 
    .DeleteAsync();