Home > Developer > JavaScript
Not much to say directly on the code
Organize original: http://blog.csdn.net/liujin4049/article/details/1244065
<title>TEST</title>
<style>
Body
TD {
Font-family:verdana, ARIAL, Helvetica, Sans-serif;
font-size:12px;
}
</style>
<script type= "Text/javascript" >
var start = 0;
var end = 0;
function Add () {
var TextBox = document.getElementById ("Ta");
var pre = textBox.value.substr (0, start);
var post = TextBox.value.substr (end);
Textbox.value = pre + document.getElementById ("Inputtext"). Value + post;
}
function Savepos (TextBox) {
If it's Firefox (1.5), the method is simple.
if (typeof (Textbox.selectionstart) = = "Number") {
start = Textbox.selectionstart;
end = Textbox.selectionend;
}
Here is the IE (6.0) method, very troublesome, but also to calculate the '/n '
else if (document.selection) {
var range = Document.selection.createRange ();
if (Range.parentelement (). id = = textbox.id) {
Create a selection of the whole textarea
var range_all = Document.body.createTextRange ();
Range_all.movetoelementtext (TextBox);
Two range, one is the selected text (range), the other is the entire textarea (Range_all)
Range_all.compareendpoints () Compares two endpoints, if Range_all is more left (further to the right) than range, then//returns a value less than 0, then Range_all moves to the right point, Until the start of the two range is the same.
Calculate selection start point by moving beginning of Range_all to beginning of range
for (start = 0; Range_all.compareendpoints ("Starttostart", Range) < 0; start++)
Range_all.movestart (' character ', 1);
Get number of line breaks from textarea start to selection start and add them to start
Calculate/N
for (var i = 0; I <= start; i++) {
if (textBox.value.charAt (i) = = '/n ')
start++;
}
Create a selection of the whole textarea
var range_all = Document.body.createTextRange ();
Range_all.movetoelementtext (TextBox);
Calculate selection end point by moving beginning of Range_all to end of range
for (end = 0; range_all.compareendpoints (' Starttoend ', range) < 0; end++)
Range_all.movestart (' character ', 1);
Get number of line breaks from textarea start to selection end and add them to end
for (var i = 0; I <= end; i++) {
if (textBox.value.charAt (i) = = '/n ')
end++;
}
}
}
document.getElementById ("Start"). Value = start;
document.getElementById ("End"). Value = end;
}
</script>
<body>
<form action= "a.cgi" >
<table border= "1" cellspacing= "0" cellpadding= "0" >
<tr>
<td>start:
<input type= "text" id= "Start" size= "3"/>
</td>
<td>end:
<input type= "text" id= "End" size= "3"/>
</td>
</tr>
<tr>
<TD colspan= "2" >
<textarea id= "Ta" onkeydown= "Savepos (This)" onkeyup= "Savepos [This]" onmousedown= "Savepos (This)" onmouseup= " Savepos (This) "
Onfocus= "Savepos (This)" rows= "cols=" ></textarea>
</td>
</tr>
<tr>
<td>
<input type= "text" id= "Inputtext"/>
</td>
<td>
<input type= "button" onclick= "Add ()" value= "Add Text"/>
</td>
</tr>
</table>
</form>
</body>
JavaScript Gets the cursor location in textarea, add value
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