Html Javascript函数在按键时只输入字母
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Javascript Function to enter only alphabets on keypress
提问by Lucy
I want to enter only character values inside a <textarea>and numeric values in another. I have been able to make a JavaScript function which only allows numeric values to be entered in the <textarea>using onkeypress. This works in Firefox and Chrome.
我只想在 a 中输入字符值<textarea>，在另一个中输入数值。我已经能够制作一个 JavaScript 函数，它只允许在<textarea>using 中输入数值onkeypress。这适用于 Firefox 和 Chrome。
For alphabets I am creating another JavaScript function using windows.eventproperty. Only problem is this works only in Chrome and not in Firefox.
对于字母表，我正在使用windows.event属性创建另一个 JavaScript 函数。唯一的问题是这仅适用于 Chrome 而不适用于 Firefox。
I want to know how to allow only alphabets to be entered using onkeypressevent as used for entering only numeric values?
我想知道如何onkeypress使用用于仅输入数值的事件仅允许输入字母？
function isNumberKey(evt){ <!--Function to accept only numeric values-->
//var e = evt || window.event;
var charCode = (evt.which) ? evt.which : evt.keyCode
if (charCode != 46 && charCode > 31
&& (charCode < 48 || charCode > 57))
return false;
return true;
}
function ValidateAlpha(evt)
{
var keyCode = (evt.which) ? evt.which : evt.keyCode
if ((keyCode < 65 || keyCode > 90) && (keyCode < 97 || keyCode > 123) && keyCode != 32)
return false;
return true;
}<label for="cname" class="label">The Risk Cluster Name</label>
<textarea id="cname" rows="1px" cols="20px" style="resize:none" placeholder="Cluster Name" onKeyPress="return ValidateAlpha(event);"></textarea>
<br>
<label for="cnum">Risk Cluster Number:</label>
<textarea id="cmun" rows="1px" cols="12px" style="resize:none" placeholder="Cluster Number" onkeypress="return isNumberKey(event)"></textarea>回答by Hrushi
function lettersOnly()
{
var charCode = event.keyCode;
if ((charCode > 64 && charCode < 91) || (charCode > 96 && charCode < 123) || charCode == 8)
return true;
else
return false;
}
<input type="text" name="fname" value="" onkeypress="return lettersOnly(event)"/>
回答by Josh Sherick
If you don't need to support older browsers I would use the inputevent. This way you can also catch non-alpha characters if the user pastes text into the textarea.
如果您不需要支持旧浏览器，我会使用该input事件。如果用户将文本粘贴到textarea.
I cleaned up your HTML a little bit. The most important changes are to the events on cnameand cnum. Note that the event in both cases has been changed to oninput.
我清理了你的 HTML 一点点。最重要的变化是对事件cname和cnum。请注意，这两种情况下的事件都已更改为oninput。
<label for="cname" class="label"> The Risk Cluster Name</label>
<textarea id="cname" rows="1" cols="20" style="resize:none" placeholder="Cluster Name" oninput="validateAlpha();"></textarea>
<label for="cnum">Risk Cluster Number:</label>
<textarea id="cmun" rows="1" cols="12" style="resize:none" placeholder="Cluster Number" oninput="isNumberKey();"></textarea><br /><br /><br />
Assuming you want cnameto only accept characters in the alphabet and cnumto only accept numbers, your JavaScript should be:
假设您只想cname接受字母表中的字符并且cnum只接受数字，您的 JavaScript 应该是：
function validateAlpha(){
var textInput = document.getElementById("cname").value;
textInput = textInput.replace(/[^A-Za-z]/g, "");
document.getElementById("cname").value = textInput;
}
function isNumberKey(){
var textInput = document.getElementById("cmun").value;
textInput = textInput.replace(/[^0-9]/g, "");
document.getElementById("cmun").value = textInput;
}
This code uses regular expressions, a way to match patterns in strings.
此代码使用正则表达式，这是一种匹配字符串模式的方法。
回答by Siddhartha esunuri
Best Uses
最佳用途
<input type="text" name="checkno" id="checkno" class="form-control" value="" onkeypress="return isNumber(event)"/>
<input type="text" name="checkname" id="checkname" class="form-control" value="" onkeypress="return isAlfa(event)"/>
function isNumber(evt) {
evt = (evt) ? evt : window.event;
var charCode = (evt.which) ? evt.which : evt.keyCode;
if (charCode > 31 && (charCode < 48 || charCode > 57)) {
return false;
}
return true;
}
function isAlfa(evt) {
evt = (evt) ? evt : window.event;
var charCode = (evt.which) ? evt.which : evt.keyCode;
if (charCode > 31 && (charCode < 65 || charCode > 90) && (charCode < 97 || charCode > 122)) {
return false;
}
return true;
}
回答by vasudhendra
function digitonly(input,event){
var keyCode = event.which ? event.which : event.keyCode;
var lisShiftkeypressed = event.shiftKey;
if(lisShiftkeypressed && parseInt(keyCode) != 9){return false;}
if((parseInt(keyCode)>=48 && parseInt(keyCode)<=57) || keyCode==37/*LFT ARROW*/ || keyCode==39/*RGT ARROW*/ || keyCode==8/*BCKSPC*/ || keyCode==46/*DEL*/ || keyCode==9/*TAB*/ || keyCode==45/*minus sign*/ || keyCode==43/*plus sign*/){return true;}
BootstrapDialog.alert("Enter Digits Only");
input.focus();
return false;
}
function alphaonly(input,event){
var keyCode = event.which ? event.which : event.keyCode;
//Small Alphabets
if(parseInt(keyCode)>=97 && parseInt(keyCode)<=122){return true;}
//Caps Alphabets
if(parseInt(keyCode)>=65 && parseInt(keyCode)<=90){return true;}
if(parseInt(keyCode)==32 || parseInt(keyCode)==13 || parseInt(keyCode)==46 || keyCode==9/*TAB*/ || keyCode==8/*BCKSPC*/ || keyCode==37/*LFT ARROW*/ || keyCode==39/*RGT ARROW*/ ){return true;}
BootstrapDialog.alert("Only Alphabets are allowed")
input.focus();
return false;
}
回答by RekhaShanmugam
hi try below code it worked for me in all browsers, it allows numbers and few special characters like,.+-() : in the textbox use as follows
嗨，试试下面的代码，它在所有浏览器中都对我有用，它允许数字和一些特殊字符，如,.+-() ：在文本框中使用如下
<asp:Textbox Id="txtPhone" runat="server" onKeyPress="return onlyNumbersandSpecialChar()"> </asp:Textbox>
function onlyNumbersandSpecialChar(evt) {
var e = window.event || evt;
var charCode = e.which || e.keyCode;
if (charCode > 31 && (charCode < 48 || charCode > 57 || charCode > 107 || charCode > 219 || charCode > 221) && charCode != 40 && charCode != 32 && charCode != 41 && (charCode < 43 || charCode > 46)) {
if (window.event) //IE
window.event.returnValue = false;
else //Firefox
e.preventDefault();
}
return true;
}
</script>
