門外漢的筆記

Stopwatch Class
 

 
HDR(HeaDer Row)

List如同Array一樣,可以建立許多陣列元素,但是卻比Array來的靈活.
例如要建立一陣列元素,Array需要先宣告陣列長度,而List不需要.

當欄位增加且資料量變多，在載入資料時，會延遲好幾秒才顯示，若捲動datagridview捲軸，會發生不順閃爍現象。
解決方法一:使用虛擬填充模式(無效)

using System.Reflection;
public partial class Form1 : Form
{   
     private Customer customerInEdit;
     private System.Collections.ArrayList customers =
                   new System.Collections.ArrayList();
     private Customer customerInEdit;
     private int rowInEdit = -1;
     private bool rowScopeCommit = true;

}

private void Form1_Load(object sender, EventArgs e)
{
     this.dataGridView1.VirtualMode = true;
     this.dataGridView1.CellValueNeeded += new
            DataGridViewCellValueEventHandler(dataGridView1_CellValueNeeded);
}

private void dataGridView1_CellValuePushed(object sender,
            System.Windows.Forms.DataGridViewCellValueEventArgs e)
{
            Customer customerTmp = null;
            if (e.RowIndex < this.customers.Count-1)
            {
                // If the user is editing a new row, create a new Customer object.
                if (this.customerInEdit == null)
                {
                    this.customerInEdit = new Customer(
                        ((Customer)this.customers[e.RowIndex]).CompanyName,
                        ((Customer)this.customers[e.RowIndex]).ContactName);
                }
                customerTmp = this.customerInEdit;
                this.rowInEdit = e.RowIndex;
            }
            else
            {
                customerTmp = this.customerInEdit;
            }
            // Set the appropriate Customer property to the cell value entered.
            String newValue = e.Value as String;
            switch (this.dataGridView1.Columns[e.ColumnIndex].Name)
            {
                case "contactNameColumn0":
                    customerTmp.CompanyName = newValue;
                    break;
                case "contactNameColumn1":
                    customerTmp.ContactName = newValue;
                    break;
            }
}

如果直接將變數宣告在header file，當你的程式引用兩次以上時，經由編譯會發生錯誤的情況。
因此在程式第一次宣告變數後，其他地方則以extern方式宣告，告知編譯器在其他地方已經宣告了這個變數。
 
//MYFunction.cpp

命名空間System
String類別
方法:  數值轉字串,字串比對,搜尋,索引

String 類別
String::Format("{0:D}",i); //字串格式化 , 0:D為十進位格式.




數值
格式
結果


123456.789
###,###.###
123,456.789


123456.789
###.##
123456.79


1234.56
00000.000
01234.560


1234.56
$##,###.##
$1,234.56

副程式

int *Function(void)
{
    int DataArray[10];
    for( int i ; i = 0; i < 10; i++ )
        DataArray[i] = i ;
   
    return DataArray;
}

 

主程式

int main(void)
{
    int *ReciveData;
    ReciveData=Function();
  
    return 0;
}