如何清空一个ArrayList类型的数组？

tob 2003-09-23 09:15:17

ArrayList Arr1;
怎样清空这个数组，好像用Arr1.clear()不行。
用Array.Clear(Arr1,0,Arr1.Capacity)也不行，怎样清空ArrayList的数组呢？

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大户翁 2003-09-23

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如 ArrayList.clear() 不行; 则用 ArrayList=null;

Soking 2003-09-23

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ArrayList.clear

hpfeng 2003-09-23

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Clear()行的，我也用过

acewang 2003-09-23

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// Creates and initializes a new ArrayList.
ArrayList myAL = new ArrayList();
myAL.Add( "The" );
myAL.Add( "quick" );
myAL.Add( "brown" );
myAL.Add( "fox" );
myAL.Add( "jumped" );
myAL.Add( "over" );
myAL.Add( "the" );
myAL.Add( "lazy" );
myAL.Add( "dog" );

// Displays the ArrayList.
Console.WriteLine( "The ArrayList initially contains the following:" );
PrintValues( myAL );

// Removes the element containing "lazy".
myAL.Remove( "lazy" );

// Displays the current state of the ArrayList.
Console.WriteLine( "After removing \"lazy\":" );
PrintValues( myAL );

// Removes the element at index 5.
myAL.RemoveAt( 5 );

kfy0002 2003-09-23

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用clear()行，我试过！

private void button1_Click(object sender, System.EventArgs e)
{
System.Collections.ArrayList arr = new System.Collections.ArrayList();
arr.Add("aa");
arr.Add("bb");
MessageBox.Show(arr.Count.ToString());
arr.Clear();
MessageBox.Show(arr.Count.ToString());

}

acewang 2003-09-23

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using System;
using System.Collections;
public class SamplesArrayList {

public static void Main() {

// Creates and initializes a new ArrayList.
ArrayList myAL = new ArrayList();
myAL.Add( "The" );
myAL.Add( "quick" );
myAL.Add( "brown" );
myAL.Add( "fox" );
myAL.Add( "jumped" );

// Displays the count, capacity and values of the ArrayList.
Console.WriteLine( "Initially," );
Console.WriteLine( " Count : {0}", myAL.Count );
Console.WriteLine( " Capacity : {0}", myAL.Capacity );
Console.Write( " Values:" );
PrintValues( myAL );

// Trim the ArrayList.
myAL.TrimToSize();

// Displays the count, capacity and values of the ArrayList.
Console.WriteLine( "After TrimToSize," );
Console.WriteLine( " Count : {0}", myAL.Count );
Console.WriteLine( " Capacity : {0}", myAL.Capacity );
Console.Write( " Values:" );
PrintValues( myAL );

// Clear the ArrayList.
myAL.Clear();

// Displays the count, capacity and values of the ArrayList.
Console.WriteLine( "After Clear," );
Console.WriteLine( " Count : {0}", myAL.Count );
Console.WriteLine( " Capacity : {0}", myAL.Capacity );
Console.Write( " Values:" );
PrintValues( myAL );

// Trim the ArrayList again.
myAL.TrimToSize();

// Displays the count, capacity and values of the ArrayList.
Console.WriteLine( "After the second TrimToSize," );
Console.WriteLine( " Count : {0}", myAL.Count );
Console.WriteLine( " Capacity : {0}", myAL.Capacity );
Console.Write( " Values:" );
PrintValues( myAL );
}

public static void PrintValues( IEnumerable myList ) {
System.Collections.IEnumerator myEnumerator = myList.GetEnumerator();
while ( myEnumerator.MoveNext() )
Console.Write( "\t{0}", myEnumerator.Current );
Console.WriteLine();
}
}

tob 2003-09-23