JS在TextArea光标位置插入文字并实现移动光标到文字末尾

=IE支持document.selection
=Firefox，Chrome,Safari以及Opera都有selectionStart和selectionEnd属性

function insertText(obj,str) { 
if (document.selection) { 
var sel = document.selection.createRange(); 
sel.text = str; 
} else if (typeof obj.selectionStart === 'number' && typeof obj.selectionEnd === 'number') { 
var startPos = obj.selectionStart, 
endPos = obj.selectionEnd, 
cursorPos = startPos, 
tmpStr = obj.value; 
obj.value = tmpStr.substring(0, startPos) + str + tmpStr.substring(endPos, tmpStr.length); 
cursorPos += str.length; 
obj.selectionStart = obj.selectionEnd = cursorPos; 
} else { 
obj.value += str; 
} 
} 
function moveEnd(obj){ 
obj.focus(); 
var len = obj.value.length; 
if (document.selection) { 
var sel = obj.createTextRange(); 
sel.moveStart('character',len); 
sel.collapse(); 
sel.select(); 
} else if (typeof obj.selectionStart == 'number' && typeof obj.selectionEnd == 'number') { 
obj.selectionStart = obj.selectionEnd = len; 
} 
}

<input type="button" onclick="insertText(document.getElementById('text'),' 新文字—YoyiorLee ')" value="插入文字"></input>

<input type="button" onclick="moveEnd(document.getElementById('text'))" value="移到末尾"></input>