jQuery或者JavaScript實現在textarea光標處插入文本

1.Jquery函數實現：

1. $(function() {
2. /* 在textarea處插入文本--Start */
3. (function($) {
4. $.fn
5. .extend({
6. insertContent : function(myValue, t) {
7. var $t = $(this)[0];
8. if (document.selection) { // ie
9. this.focus();
10. var sel = document.selection.createRange();
11. sel.text = myValue;
12. this.focus();
13. sel.moveStart('character', -l);
14. var wee = sel.text.length;
15. if (arguments.length == 2) {
16. var l = $t.value.length;
17. sel.moveEnd("character", wee + t);
18. t <= 0 ? sel.moveStart("character", wee - 2 * t
19. - myValue.length) : sel.moveStart(
20. "character", wee - t - myValue.length);
21. sel.select();
22. }
23. } else if ($t.selectionStart
24. || $t.selectionStart == '0') {
25. var startPos = $t.selectionStart;
26. var endPos = $t.selectionEnd;
27. var scrollTop = $t.scrollTop;
28. $t.value = $t.value.substring(0, startPos)
29. + myValue
30. + $t.value.substring(endPos,
31. $t.value.length);
32. this.focus();
33. $t.selectionStart = startPos + myValue.length;
34. $t.selectionEnd = startPos + myValue.length;
35. $t.scrollTop = scrollTop;
36. if (arguments.length == 2) {
37. $t.setSelectionRange(startPos - t,
38. $t.selectionEnd + t);
39. this.focus();
40. }
41. } else {
42. this.value += myValue;
43. this.focus();
44. }
45. }
46. })
47. })(jQuery);
48. /* 在textarea處插入文本--Ending */
49. });

$(文本域選擇器).insertContent("插入的內容");
//$(文本域選擇器).insertContent("插入的內容"，數值); //根據數值選中插入文本內容兩邊的邊界, 數值: 0是表示插入文字全部選擇，-1表示插入文字兩邊各少選中一個字符。

2.JavaScript實現：

1. function insertText(obj,str) {
2. if (document.selection) {
3. var sel = document.selection.createRange();
4. sel.text = str;
5. } else if (typeof obj.selectionStart === 'number' && typeof obj.selectionEnd === 'number') {
6. var startPos = obj.selectionStart,
7. endPos = obj.selectionEnd,
8. cursorPos = startPos,
9. tmpStr = obj.value;
10. obj.value = tmpStr.substring(0, startPos) + str + tmpStr.substring(endPos, tmpStr.length);
11. cursorPos += str.length;
12. obj.selectionStart = obj.selectionEnd = cursorPos;
13. } else {
14. obj.value += str;
15. }
16. }
17. function moveEnd(obj){
18. obj.focus();
19. var len = obj.value.length;
20. if (document.selection) {
21. var sel = obj.createTextRange();
22. sel.moveStart('character',len);
23. sel.collapse();
24. sel.select();
25. } else if (typeof obj.selectionStart == 'number' && typeof obj.selectionEnd == 'number') {
26. obj.selectionStart = obj.selectionEnd = len;
27. }
28. }