通过 javascript 在光标处插入文本
2007-07-11 22:22 晓风残月 阅读(2140) 评论(5) 编辑 收藏 举报
功能：实现将指定文本插入到目标文本框中的最后一次光标位置
通过一个窗口的全局变量记录目标文本框的最后一次光标位置，因为当你离开此文本框之后，焦点也就移开了。
获取光标位置（包括选中文本时的起始位置）使用函数，采用 Marshall 的方法:
http://blog.csdn.net/liujin4049/archive/2006/09/19/1244065.aspx
非常感谢 Marshall
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<!--http://community.csdn.net/Expert/TopicView3.asp?id=5649731-->
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>Insert Text into TextBox at Cursor Position by Javascript</title>
<script type="text/javascript">
var cursPos; // 窗口全局变量，保存目标 TextBox 的最后一次活动光标位置
function insertText() {
var txt1 = document.getElementById("Text1");
var txt2 = document.getElementById("Text2");
//debugger;
if(!cursPos) TraceCursorPosition(txt2); // 获取光标位置
txt2.value = txt2.value.slice(0, cursPos.start) +
txt1.value + txt2.value.slice(cursPos.end)
}
// 跟踪光标位置
function TraceCursorPosition(obj)
{
//debugger;
cursPos = $CursorPosition(obj);
}
// 返回光标所在位置
/*
* source: http://blog.csdn.net/liujin4049/archive/2006/09/19/1244065.aspx
* acknowledges for Marshall
* example:
* var myTextBox = document.getElementById("MyTextBoxID");
* var cursPos = $CursorPosition(myTextBox);
* alert(cursPos.item[0] + " " + cursPos.item[1]);
* // OR
* alert(cursPos.start + " " + cursPos.end);
*/
function $CursorPosition(textBox){
var start = 0, end = 0;
//如果是Firefox(1.5)的话，方法很简单
if(typeof(textBox.selectionStart) == "number"){
start = textBox.selectionStart;
end = textBox.selectionEnd;
}
//下面是IE(6.0)的方法，麻烦得很，还要计算上'\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);
//两个range，一个是已经选择的text(range)，一个是整个textarea(range_all)
//range_all.compareEndPoints()比较两个端点，如果range_all比range更往左(further to the left)，则
//返回小于0的值，则range_all往右移一点，直到两个range的start相同。
// 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
// 计算一下\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 ++;
}
}
}
//return [start, end]; // 包括选中区域的起始位置
// modified to return as Object
return {"start": start, "end": end, "item": [start, end]};
}
</script>
</head>
<body>
input :<input id="Text1" type="text" /><input id="Button1" type="button" value="Insert" onclick="insertText()" /><br />
output:<textarea id="Text2" cols="40" rows="10" onkeydown="TraceCursorPosition(this)" onkeypress="TraceCursorPosition(this)" onfocus="TraceCursorPosition(this)" onselect="TraceCursorPosition(this)" onmouseover="TraceCursorPosition(this)" onmousedown="TraceCursorPosition(this)">hello world!</textarea><br />
</body>
</html>
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通过一个窗口的全局变量记录目标文本框的最后一次光标位置，因为当你离开此文本框之后，焦点也就移开了。
获取光标位置（包括选中文本时的起始位置）使用函数，采用 Marshall 的方法:
http://blog.csdn.net/liujin4049/archive/2006/09/19/1244065.aspx
非常感谢 Marshall
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><!--http://community.csdn.net/Expert/TopicView3.asp?id=5649731--><html xmlns="http://www.w3.org/1999/xhtml" ><head> <title>Insert Text into TextBox at Cursor Position by Javascript</title> <script type="text/javascript">
var cursPos; // 窗口全局变量，保存目标 TextBox 的最后一次活动光标位置 function insertText() { 
var txt1 = document.getElementById("Text1"); var txt2 = document.getElementById("Text2"); //debugger; if(!cursPos) TraceCursorPosition(txt2); // 获取光标位置 txt2.value = txt2.value.slice(0, cursPos.start) + txt1.value + txt2.value.slice(cursPos.end) } // 跟踪光标位置 function TraceCursorPosition(obj) { //debugger; cursPos = $CursorPosition(obj); } // 返回光标所在位置 /* * source: http://blog.csdn.net/liujin4049/archive/2006/09/19/1244065.aspx * acknowledges for Marshall * example: * var myTextBox = document.getElementById("MyTextBoxID"); * var cursPos = $CursorPosition(myTextBox); * alert(cursPos.item[0] + " " + cursPos.item[1]); * // OR * alert(cursPos.start + " " + cursPos.end); */ function $CursorPosition(textBox){ var start = 0, end = 0; //如果是Firefox(1.5)的话，方法很简单 if(typeof(textBox.selectionStart) == "number"){ start = textBox.selectionStart; end = textBox.selectionEnd; } //下面是IE(6.0)的方法，麻烦得很，还要计算上'\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); //两个range，一个是已经选择的text(range)，一个是整个textarea(range_all) //range_all.compareEndPoints()比较两个端点，如果range_all比range更往左(further to the left)，则 //返回小于0的值，则range_all往右移一点，直到两个range的start相同。 // 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 // 计算一下\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 ++; } } } //return [start, end]; // 包括选中区域的起始位置 // modified to return as Object return {"start": start, "end": end, "item": [start, end]}; } </script></head><body> input :<input id="Text1" type="text" /><input id="Button1" type="button" value="Insert" onclick="insertText()" /><br /> output:<textarea id="Text2" cols="40" rows="10" onkeydown="TraceCursorPosition(this)" onkeypress="TraceCursorPosition(this)" onfocus="TraceCursorPosition(this)" onselect="TraceCursorPosition(this)" onmouseover="TraceCursorPosition(this)" onmousedown="TraceCursorPosition(this)">hello world!</textarea><br /></body></html>下载
