我有一個扁平的物體，它看起來像下圖
public class Test
{
public string Name {get; set;}
public string Number {get; set;}
public string Description {get; set;}
public string Name1 {get; set;}
public string Name2 {get; set;}
}
我的資料如下所示
List<Test> tests = new List<Test>
{
new Test{ Name = "nameA", Number=8, Description="description", Name1 = "test 1", Name2="test name1" },
new Test{ Name = "nameB", Number=3, Description="description2", Name1 = "test 2", Name2="test name2" },
new Test{ Name = "nameC", Number=4, Description="description3", Name1 = "test 3", Name2="test name3" },
};
我正在嘗試形成一個如下所示的物件串列
我使用下面的邏輯來形成一個串列物件，但未能將所有物件添加到其中，
List<dynamic> testList = new();
int rowIndex = 1;
foreach (var testDt in tests)
{
dynamic testData = new ExpandoObject();
if (rowIndex % 2 != 0)
{
testData.Name = testDt.Name;
testData.Description = testDt.Description;
testData.Number = testDt.Number;
}
else
{
testData.Name1 = testDt.Name1;
testData.Name2 = testDt.Name2;
}
testList.Add(testData);
rowIndex ;
}
但是如果串列有更多專案，這個邏輯不會將所有專案添加到串列中，任何人都可以讓我知道我上面代碼的錯誤。
提前謝謝了！！！
uj5u.com熱心網友回復：
干得好：
List<Test> tests = new List<Test>
{
new Test{ Name = "nameA", Number = 8, Description = "description", Name1 = "test 1", Name2 = "test name1" },
new Test{ Name = "nameB", Number = 3, Description = "description2", Name1 = "test 2", Name2 = "test name2" },
new Test{ Name = "nameC", Number = 4, Description = "description3", Name1 = "test 3", Name2 = "test name3" },
};
var results =
from t in tests
from r in new []
{
new { t.Name, Number = t.Number.ToString(), t.Description, Name1 = "", Name2 = "", },
new { Name = "", Number = "", Description = "", Name1 = t.Name1, t.Name2, },
}
select r;
這給了我：
要使用常規foreach回圈，這將起作用：
public class Output
{
public string Name { get; set; }
public string Number { get; set; }
public string Description { get; set; }
public string Name1 { get; set; }
public string Name2 { get; set; }
}
var results = new List<Output>();
foreach (var t in tests)
{
results.Add(new Output() { Name = t.Name, Number = t.Number.ToString(), Description = t.Description, Name1 = "", Name2 = "", });
results.Add(new Output() { Name = "", Number = "", Description = "", Name1 = t.Name1, Name2 = t.Name2, });
}
我創建了一個新類而不是 use dynamic，因為dynamic通常會產生比它解決的更多的問題，IMO。我盡可能避免它。
最后，等效的使用 LINQ 的方法語法：
results =
tests
.SelectMany(t => new []
{
new Output() { Name = t.Name, Number = t.Number.ToString(), Description = t.Description, Name1 = "", Name2 = "", },
new Output() { Name = "", Number = "", Description = "", Name1 = t.Name1, Name2 = t.Name2, },
})
.ToList();
uj5u.com熱心網友回復：
問題是您每次迭代只向串列添加 1 個專案，但是，您需要添加 2 個專案才能獲得預期結果。
您可以簡單地執行以下操作。
foreach (var testDt in tests)
{
dynamic testData1 = new ExpandoObject();
testData1.Name = testDt.Name;
testData1.Description = testDt.Description;
testData1.Number = testDt.Number;
testList.Add(testData1);
dynamic testData2 = new ExpandoObject();
testData2.Name1 = testDt.Name1;
testData2.Name2 = testDt.Name2;
testList.Add(testData2);
}
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