c# - 单击按钮停止刷新页面

Question

我需要使 asp 按钮在单击时不刷新整个页面。

我的代码只是将图片更改为另一张图片，但图片的索引是在页面加载方法中设置的。并且每次点击按钮进入下一张图片索引时，整个页面都会刷新并调用页面加载方法。然后将索引设置回 0。

如何让页面在点击按钮时停止调用页面加载方法

这是我正在使用的基本代码

在表格中:

<tr>
    <td> <asp:Button ID="Button1" runat="server" Text="Prev" OnClick="Button1_Click" OnClientClick="return false"/> </td>
    <td> <img ID="pic" alt="" src="010.JPG" runat="server" width="200" height="200" /> </td>
    <td> <asp:Button ID="Button2" runat="server" Text="Next" OnClick="Button2_Click" OnClientClick="return false"/> </td>
</tr>

这是.cs文件

private List<String> imagePathList = new List<String> { };
private List<Boolean> isActivePath = new List<Boolean> { };

protected void Page_Load(object sender, EventArgs e)
{
        Debug.WriteLine("GALLARY *page load*");

        pic.Width = 200;
        pic.Height = 200;

        addToList();

        getImagePath(1);
}
protected void Button1_Click(object sender, EventArgs e)
{
    Debug.WriteLine("GALLARY *Button1_Click*");
    int index = getActive();
    getImagePath(index = index - 1); 
}
protected void Button2_Click(object sender, EventArgs e)
{
    Debug.WriteLine("GALLARY *Button2_Click*");
    int index = getActive();
    getImagePath(index = index + 1);
}

private void getImagePath(int index)
{
    Debug.WriteLine("GALLARY *getImagePath* index = "+index);
    int length = imagePathList.Count;

    if (index < length && index >= 0)
    {
        //pic.Src = imagePathList[index];
        //pic.Alt = imagePathList[index];
        pic.Src = imagePathList[index];
        pic.Alt = imagePathList[index];
        setActive(index);
    }
    else
    {
        pic.Src = "DOES NOT EXIST";
        pic.Alt = "DOES NOT EXIST";
    }
}

private void addToList()
{
    Debug.WriteLine("GALLARY *addToList*");
    imagePathList.Clear();
    isActivePath.Clear();

    addImage("08.JPG");
    addImage("09.JPG");
    addImage("010.JPG");
    addImage("011.JPG");
    addImage("012.JPG");
}

private void addImage(String filename)
{
    Debug.WriteLine("GALLARY *addImage* filename = "+filename);
    imagePathList.Add(filename);
    isActivePath.Add(false);
}
private void setActive(int index)
{
    Debug.WriteLine("GALLARY *setActive* index = " + index);
    for (int i = 0; i > isActivePath.Count; i++)
    {
        isActivePath[i] = false;
    }

    isActivePath[index] = true;
}
private int getActive()
{
    Debug.Write("GALLARY *getActive*");
    int temp = 0;
    for (int i = 0; i > isActivePath.Count; i++)
    {
        if (isActivePath[i] == true)
        {
            temp = i;
        }
    }
    Debug.WriteLine("index = " + temp);
    return temp;
}

Answer 1

您需要使用 UpdatePanel 进行部分更新。

<asp:ScriptManager runat="server"></asp:ScriptManager>

    <asp:UpdatePanel ID="UpdatePanel2" runat="server" UpdateMode="Always" >
    <ContentTemplate>
    <asp:Image ID="Image1" runat="server" Height="23px"  Width="24px" />

    <asp:Button ID="btnImageChange" runat="server" Text="Check" OnClick="btnImageChange_Click1"  />
     </ContentTemplate>
    <Triggers>
    <asp:AsyncPostBackTrigger ControlID="btnImageChange" EventName="Click" />
    </Triggers>
    </asp:UpdatePanel>

然后在.cs后面的代码中这样写:

protected void btnImageChange_Click1(object sender, EventArgs e)
    {
     // you can add a loop here for the list of images...
            Image1.ImageUrl = "~/Images/loading.gif";

}