我正在做一个在JS中创建表的函数。
我创建了一个变量 table_row
填充它,然后将 table_layout.appendChild(table_row);
添加到 table_layout
元素。
接下来,我通过 table_row
清除 innerHTML=''
,但在清理时,我 ALREADY 的变量已添加到元素 table_layout
也已清除。
为什么会这样? 是否应该清除添加的元素? 如何避免这种情况? 请查看 CODE 。
var columns = ["col1", "col2", "col3"];
var rows = 5;
function Table() {
var table_layout = document.createElement("table");
var table_row = document.createElement("tr");
for (var i = 0; i < columns.length; i++) {
// main row
table_row.innerHTML += "<th>" + columns[i] + "</th>";
}
table_layout.appendChild(table_row); //add in table element
// table_row.innerHTML = ""; //If you uncomment this line, then we get an empty output!
//refresh table_row html, that would generate a new line
//But when cleaning. Cleared in the previously added item in table_layout .... how??
// for (var j = 0; i < columns.length; j++) {
// table_main_row.innerHTML += '<td></td>';
// }
// for (var i = 0; i < rows; i++) {
// table_layout.appendChild(table_row);
// }
return table_layout;
}
var div = document.getElementById("qqq");
div.appendChild(Table());
&#13;
#qqq {
background: red;
}
&#13;
<div id="qqq"></div>
&#13;
答案 0 :(得分:0)
table_row
变量包含引用。您需要为每一行创建一个新元素。
// creates a DOM Element and saves a reference to it in the table_row variable
var table_row = document.createElement("tr");
// updates the DOM Element through the reference in the table_row variable
table_row.innerHTML += "<th>" + columns[i] + "</th>";
// still references the DOM Element, so you are clearing its content
// table_row.innerHTML = "";
你需要。 。
// create a new DOM Element to use
table_row = document.createElement("tr");
// then update its contents
table_main_row.innerHTML += '<td></td>';
。 。 。每次迭代。
有关教程,参考资料等内容,请参阅JavaScript on MDN。
答案 1 :(得分:0)
<!DOCTYPE html>
<html>
<head>
<script type="text/javascript" language="javascript">
var columns = ["col1", "col2", "col3"];
var rows = 5;
function createNewRow(headerRow)
{
var newRowElem = null;
try
{
newRowElem = document.createElement("tr");
for (var i = 0; i < columns.length; i++)
{
if(headerRow) newRowElem.innerHTML += "<th>" + columns[i] + "</th>";
else newRowElem.innerHTML += "<td>" + columns[i] + "</td>";
}
}
catch(e)
{
alert("createNewRow Error" + e.Message);
}
finally
{
}
return newRowElem;
}
function Table()
{
var table_layout = null;
try
{
table_layout = document.createElement("table");
// Create Header Row
table_layout.appendChild(createNewRow(true));
// Create Other Rows
for (var i = 0; i < rows; i++)
{
table_layout.appendChild(createNewRow(false));
}
}
catch(e)
{
alert("Table Error: " + e.Message);
}
finally
{
}
return table_layout;
}
</script>
<style>
#qqq {
background: red;
}
</style>
</head>
<body>
<div id="qqq"></div>
<script type="text/javascript" language="javascript">
var div = document.getElementById("qqq");
div.appendChild(Table());
</script>
</body>
</html>
答案 2 :(得分:0)
我这样做了。
var table_layout = document.createElement('table');
table_layout.setAttribute('id', 'main_table');
table_layout.setAttribute('border', '1');
var row = document.createElement('tr');
row.setAttribute('class', 'main_row');
for (var i = 0; i < this.fields.length; i++) { // строка с именами столбцов
var th = document.createElement('th');
th.setAttribute('class', 'cell_name');
th.innerHTML = this.fields[i];
row.appendChild(th);
}
table_layout.appendChild(row); //добавляем
row = document.createElement('tr'); // очищаем от старых элементов строку (переопределяем)
row.setAttribute('class', 'table_row');
var td = document.createElement('td');
td.setAttribute('class', 'table_cell');
// td.setAttribute('ondblclick', 'input_func()');
td.addEventListener('click', function () {
alert();
});
td.innerHTML='000';
for (var j = 0; j < this.fields.length; j++) { // создаем строку с N-количеством ячеек
row.appendChild(td.cloneNode(true));
}
for (var i = 0; i < this.rows; i++) { // Добавляем её есколько раз через клона
table_layout.appendChild(row.cloneNode(true));
}
但随后用表格的功能重新分配。
var table_layout = document.createElement('table');
table_layout.setAttribute('id', 'main_table');
table_layout.setAttribute('border', '1');
var row = table_layout.insertRow(0);
var cell;
for (var j = 0; j < this.fields.length; j++) {
cell = row.insertCell(j);
cell.outerHTML = '<th>' + this.fields[j] + '</th>';
cell.className = 'cell_name';
}
for (var i = 0; i < this.rows; i++) {
row = table_layout.insertRow(i + 1);
row.className = 'row_table';
for (var n = 0; n < this.fields.length; n++) {
cell = row.insertCell(n);
// cell.innerHTML = '00';
cell.className = 'table_cell';
cell.innerHTML = ' ';
}
}
return table_layout;