Javascript 单击时使用粗体字体_Javascript_Html

Javascript 单击时使用粗体字体

javascript html

Javascript 单击时使用粗体字体,javascript,html,Javascript,Html,我试图使文本变为粗体时，它被点击，当它再次点击它将恢复正常。函数addBord（e）是我到目前为止得到的，但我不确定我是否在正确的轨道上，或者我下一步应该做什么。谁能告诉我下一步该做什么 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN“ "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w

我试图使文本变为粗体时，它被点击，当它再次点击它将恢复正常。函数addBord（e）是我到目前为止得到的，但我不确定我是否在正确的轨道上，或者我下一步应该做什么。谁能告诉我下一步该做什么

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN“ "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
  <title>Address Book</title>

  <script type="text/javascript">
    function addressBookItem (fname, lname, email) {
        this.fname= fname;
        this.lname = lname; 
        this.email = email;
    }

    addressBookItem.prototype.write = function() {
        // var adrbook = "<p class='ab' First Name: " + this.fname + "&ltbr /&gt";
        var adrbook = "<tr><td>"+ this.fname + "</td>";
        adrbook += "<td>" + this.lname + "</td>";
        adrbook += "<td>" + this.email + "</td></tr>";

        document.write(adrbook);
    }

  function appendRow() {
    var theTable = document.getElementById("addressBookTbl");
    // create a newRow
    var newRow = document.createElement("tr");
    var c1 = document.createElement("td");
    var c2 = document.createElement("td");
    var c3 = document.createElement("td");
    var v1 = document.createTextNode(prompt("Please enter first name"));
    var v2 = document.createTextNode(prompt("Please enter last name"));
    var v3 = document.createTextNode(prompt("Please enter email"));
    c1.appendChild(v1);
    c2.appendChild(v2);
    c3.appendChild(v3);
    // newRow <- c1;
    newRow.appendChild(c1);
    newRow.appendChild(c2);
    newRow.appendChild(c3);
    theTable.appendChild(newRow);
    newRow.style.color="green";
  }
  newRow.addEventListener('click', addBord, false);
  function addBord(e) { 
    var target = e.target || event.srcElement;
    if(target.style.fontWeight=="bold")
      target.style.fontWeight="normal";
    else
      target.style.fontWeight="bold";
  }
</script>
</head>
<body>
    <script type="text/javascript">
        var aB1 = new addressBookItem('Roger', 'Williams', 'rwilliams@gmail.com');
        var aB2 = new addressBookItem ('Rose', 'Schultz', 'rose_s@earthlink.net');
        document.write("<table id=\"addressBookTbl\" border=\"2\"><tr><th>First Name</th><th>Last Name</th><th>EmailAddress</th></tr>");
        aB1.write();
        aB2.write();
        document.write("</table>");
    </script>
    <form>
      <br />
      <input type="button" value="append new row" onclick="appendRow()"/>
    </form>
</body>
</html>

我得到了答案。其实很简单。事件侦听器位于appendrow函数外部。请遵循以下代码：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN“ "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
  <title>Address Book</title>

  <script type="text/javascript">
    function addressBookItem (fname, lname, email) {
        this.fname= fname;
        this.lname = lname; 
        this.email = email;
    }

    addressBookItem.prototype.write = function() {
        // var adrbook = "<p class='ab' First Name: " + this.fname + "&ltbr /&gt";
        var adrbook = "<tr><td>"+ this.fname + "</td>";
        adrbook += "<td>" + this.lname + "</td>";
        adrbook += "<td>" + this.email + "</td></tr>";

        document.write(adrbook);
    }

  function appendRow() {
    var theTable = document.getElementById("addressBookTbl");
    // create a newRow
    var newRow = document.createElement("tr");
    var c1 = document.createElement("td");
    var c2 = document.createElement("td");
    var c3 = document.createElement("td");
    var v1 = document.createTextNode(prompt("Please enter first name"));
    var v2 = document.createTextNode(prompt("Please enter last name"));
    var v3 = document.createTextNode(prompt("Please enter email"));
    c1.appendChild(v1);
    c2.appendChild(v2);
    c3.appendChild(v3);
    // newRow <- c1;
    newRow.appendChild(c1);
    newRow.appendChild(c2);
    newRow.appendChild(c3);
    theTable.appendChild(newRow);
    newRow.style.color="green";
  newRow.addEventListener('click', addBord, false);//event listener inside the function
  }
  function addBord(e) { 
    var target = e.target || event.srcElement;
    if(target.style.fontWeight=="bold")
      target.style.fontWeight="normal";
    else
      target.style.fontWeight="bold";
  }
</script>
</head>
<body>
    <script type="text/javascript">
        var aB1 = new addressBookItem('Roger', 'Williams', 'rwilliams@gmail.com');
        var aB2 = new addressBookItem ('Rose', 'Schultz', 'rose_s@earthlink.net');
        document.write("<table id=\"addressBookTbl\" border=\"2\"><tr><th>First Name</th><th>Last Name</th><th>EmailAddress</th></tr>");
        aB1.write();
        aB2.write();
        document.write("</table>");
    </script>
    <form>
      <br />
      <input type="button" value="append new row" onclick="appendRow()"/>
    </form>
</body>
</html>

好吧，代码是有效的。你的问题是什么？代码看起来不错，但是你不应该使用document.write
来添加这样的HTML元素@Andy他对addBord（）有意见function@GuillaumeHarari我刚刚测试了你的整个页面，问题不在于功能，而在于你的newRow
超出了范围，JS错误是test.html:43未捕获引用错误：test.html:43未定义newRow，因为您尝试在appendRow
之后访问它