Datatable delete row

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First list the correct writing , If you just want to correct the mistake immediately, copy it first ,

protected void deleteDataRow(int RowID,DataTable dt)  
    {  
        for (int i = dt.Rows.Count - 1; i >= 0; i--)  
        {  
            if (Convert.ToInt32(dt.Rows[i]["RowID"]) == RowID)  
                dt.Rows.RemoveAt(i);  
        }  
    }  /*  Why  hovertree.com */

If you have time to learn, keep looking at the following list of possible mistakes .

　　1. If you just want to delete datatable A row in the , It can be used DataRow Of delete, But you must delete it and let DataTable know , So we need .AcceptChanges() Method , The reason is that this deletion is only an identification deletion , As we usually use in the database IsDelete Field .

　　2. You need to delete it completely datatable Of .Rows.Remove(DataRow dr) Method , Similarly, just delete a line , If you want to delete circularly, please continue to read .

　　3. To completely delete the cycle, you need to use .Rows.RemoveAt(int index) Method , So if you are foreach Lovers , Please change your taste here , And if you are for Of i++ Faithfulness fans I also hope you can change your mind . Let's first look at the forward writing of the above program （ FALSE , Unavailable ）

for (int i = 0, j = dt.Rows.Count; i < j; i++)  
        {  
            if (Convert.ToInt32(dt.Rows[i]["RowID"]) == RowID)  
                dt.Rows.RemoveAt(i);  
        }  /*  Why  hovertree.com */

The mistake of this is datatable Of RemoveAt() It will be updated after deletion dataTable Of index, So what you want to delete index It may not be your match Convert.ToInt32(dt.Rows[i][“RowID”]) == RowID Of index 了 , Even throw exceptions , Said you visited index non-existent .

　　 So from the DataTable Search up and delete , In this way, even if this line meets the conditions and is deleted , The above line is still unaffected .

Said so much , I don't know if you understand ？ In fact, writing this kind of article now seems a little ” retarded ”, More technology , I feel more and more that my foundation is not solid enough , I hope I can urge myself by recording here , Also hope to give beginners some help .

http://hovertree.com/menu/csharp/

manipulation dataset stay DataSet in DataRow It is the basic storage location for all its data , It is mainly composed of an array of values , representative DataTable A single line . DataRow It mainly includes the following information ：1、 The current value of each column in the row ,2、 The original value of each column in the row ,3、 Line status ,4、 Link between parent line and child line

Initialize a DataRow： DataTable dataTable＝dataSet.Tables[0]; DataRow newRow=dataTable.NewRow(); // use dataTable Generate DataRow You can use dataTable The pattern inside dataTable.Rows.Add(newRow);

Delete row ： DataTable.Rows.Remove( Row instance ); DataTable.Rows.RemoveAt( Line number ); DataRow.Delete(); // The row itself is removed

Reading and writing DataRow Value ： row[“ Name ”],row[ Column number ] You can reference one of these properties DataColumn a=dataTable.Columns(“ Name ”); // You can get a column

Make batch changes to rows ： BeginEdit() Start changing ,EndEdit() End the change , At the same time, write the change result to DataSet,CancelEdit(), Cancel the change for example ： row.BeginEdit(); Yes row Make changes row.EndEdit();

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