改变输入值,同时仍允许用户输入 [英] Changing input value while still allowing the user to type
问题描述
是否有可能使用JavaScript或jQuery在用户输入时更改文本输入字段的内容?
例如,键入 a + up
会将 a
更改为å
,同时保持输入光标位于同一位置。
是的,立即更改并保持 selectionStart
和 selectionEnd
在上一个位置: http://jsfiddle.net/pimvdb/p2jL3/3/ 。
selectionStart
和 selectionEnd
表示选择界限,并且在没有选择时相等,在这种情况下它们表示光标位置。
编辑:决定制作一个jQuery插件,因为它稍后可能会派上用场,并且很容易以任何方式实现。
(function($){
var down = {}; //当前按下的键
replacements = {//替换映射
37:{//保留
'a ':'
},
38:{//增加
'a':''
},
39:{// right
'a':'á'
},
40:{// down
'a':'à'
}
};
$ .fn.specialChars = function(){
return this.keydown(function(e){
down [e.keyCode] = true; //这个键是现在下降
if(down [37] || down [38] || down [39] || down [40]){//如果箭头键关闭
var value = $(this).val(),// textbox value
pos = $(this).prop('selectionStart'),//游标位置
char = value.charAt(pos - 1) ,//旧字符
替换=替换[e.keyCode] [char] || char; //新字符(如果可用)
$(this).val(value.substring(0 ,pos - 1)//将文本设置为:字符前的文本
+替换// +新字符
+ value.substring(pos))// +光标后的文本
.prop({selectStart:pos,//重置光标位置
selectionEnd:pos});
返回false; //防止开始/结束文本框
}
})。keyup(function(e){
down [e.keyCode] = false; //这个键现在没有关闭(function(){
down = {}; //当文本框丢失焦点时,所有的键都没有关闭
});
};
})(jQuery);
Is it possible, using JavaScript or jQuery, to change the content of a text input field while the user types?
E.g. typing a + up
would change the a
to å
, while keeping the input cursor at the same position.
Yes, change it on the fly and keep selectionStart
and selectionEnd
at the previous position: http://jsfiddle.net/pimvdb/p2jL3/3/.
selectionStart
and selectionEnd
represent the selection bounds, and are equal to each other when there is no selection, in which case they represent the cursor position.
Edit: Decided to make a jQuery plugin of it, since it may come in handy later and it's easy to implement anywhere that way.
(function($) {
var down = {}; // keys that are currently pressed down
replacements = { // replacement maps
37: { // left
'a': 'ã'
},
38: { // up
'a': 'â'
},
39: { // right
'a': 'á'
},
40: { // down
'a': 'à'
}
};
$.fn.specialChars = function() {
return this.keydown(function(e) {
down[e.keyCode] = true; // this key is now down
if(down[37] || down[38] || down[39] || down[40]) { // if an arrow key is down
var value = $(this).val(), // textbox value
pos = $(this).prop('selectionStart'), // cursor position
char = value.charAt(pos - 1), // old character
replace = replacements[e.keyCode][char] || char; // new character if available
$(this).val(value.substring(0, pos - 1) // set text to: text before character
+ replace // + new character
+ value.substring(pos)) // + text after cursor
.prop({selectionStart: pos, // reset cursor position
selectionEnd: pos});
return false; // prevent going to start/end of textbox
}
}).keyup(function(e) {
down[e.keyCode] = false; // this key is now not down anymore
}).blur(function() {
down = {}; // all keys are not down in the textbox when it loses focus
});
};
})(jQuery);
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