ajax实现输入框提示信息

淡淡的烟草味﹌ 2021-09-16 23:32 446阅读 0赞

![20181112145906611.png][]

HtmlPage1.html

<head>
        <meta charset="utf-8" />
        <title></title>
        <script type="text/javascript">
            function loadXMLDoc(str)
            {
                var xmlhttp;
                if (str.length == 0)
                {
                    document.getElementById("txtHint").innerHTML = "";
                    return;
                }
                if (window.XMLHttpRequest)
                {
                    xmlhttp = new XMLHttpRequest();
                }
                else
                {
                    xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
                }
                xmlhttp.open("GET", "WebForm1.aspx?q="+str , true);
                xmlhttp.send();
                xmlhttp.onreadystatechange = callback;
    
                function callback()
                {
                    if (xmlhttp.readyState == 4 && xmlhttp.status == 200)
                    {
                        document.getElementById("txtHint").innerHTML = xmlhttp.responseText;
                    }
                }
            }
        </script>
    </head>
    <body>
        <form name="form1">
            <h3>请在输入框中输入字母(A-G)：</h3>
            <input id="Text1" name="Text1" type="text" onkeyup="loadXMLDoc(this.value)" />
            <br />
    
            提示： <div id="txtHint"></div>
        </form>
    
    </body>

WebForm1.aspx.cs

protected void Page_Load(object sender, EventArgs e)
            {
                Response.Expires = -1;
                string[] a =
                {
                    "Asdf","Awet","Bsdf","Bi","Csad","Coew",
                    "Dasd","Dfg","Egfd","Efh","Fdsfh","Feth","Gsfgg","Grhf"
                };
                string q = Request.Params["q"].ToUpper();
                string hint = "";
                if (q.Length > 0)
                {
                    int i;
                    for (i = 0; i < 14; i++)
                    {
                        string b = a[i].Substring(0, q.Length);
                        if (q == b)
                        {
                            if(hint == "")
                            {
                                hint = a[i];
                            }
                            else
                            {
                                hint = hint + "," + a[i];
                            }
                        }
                    }
                }
                if (hint == "")
                {
                    Response.Write("没有提示");
                }
                else
                {
                    Response.Write(hint);
                }
                Response.End();
            }

![20181112150116439.png][]

[20181112145906611.png]: /images/20210725/a647652ca66447b09df983517013d0da.png
[20181112150116439.png]: /images/20210725/ab96fcb7a3174d128b708713d312c1e3.png