GetEnumerator系列用法

1：用在将哈希表读到对象Idictionaryenumerator中

public void show()
{
    idictionaryenumerator myenumerator  = food.getenumerator();
    console.writeline("food list:");
    console.writeline("------------------------------");
    string strfoodlist = "";
    while(myenumerator.movenext())
    {
        strfoodlist = strfoodlist + "\n\n" + myenumerator.key.tostring();
        strfoodlist = strfoodlist + ":\t" +myenumerator.value.tostring();
    }
    console.writeline(strfoodlist);
    console.writeline("\n------------------------------");
}

//当然如果纯粹讨论方法的实现，我们也可以这样写


public void show()
{
    idictionaryenumerator myenumerator  = food.getenumerator();
    console.writeline("food list:");
    console.writeline("------------------------------");
    string strfoodlist = "";
    foreach(string keys in myenumerator.keys)
    {
        strfoodlist = strfoodlist + "\n\n" + keys.tostring();
        strfoodlist = strfoodlist + ":\t" +myenumerator[keys].tostring();
    }
    console.writeline(strfoodlist);
    console.writeline("\n------------------------------");
}

//这里还需要研究，为什么要读到idictionaryenumerator 对象，有啥作用呢 ???

 

2：用在读取datatable中某行，并对该行进行操作行为

public void test()
{
    datatable usertable = new datatable("persontable");
    usertable.columns.add("id",typeof(int));
    usertable.columns.add("name",typeof(string));

    datatablereader reader = usertable.createdatareader();
    usertable.rows.add(new object[]{1,"peter"});
    usertable.rows.add(new object[]{2,"mary"});
    usertable.rows.add(new object[]{3,"andy"});
    usertable.rows.add(new object[]{4,"russs"});

    ienumerator enumerator = reader.getenumerator();
    while(enumerator.movenext())
    {
        dbdatarecord datarecord = (dbdatarecord)enumerator.current;
        if(!isrowdeleted)
        {
            usertable.rows[2].delete();
        }
        console.writteline(datarecord.getstring(1));
    }
}

 

 

3：用在读取字符串，用char方式一个个展示出来

 

public void testchar(string str)
{
    ienumerator strenum = str.getenumerator();
    while(streunm.movenext())
    {
        console.write(str.current);//这样可以将字符串，按一个个字符输出
    }
}