当 javascript 返回 true 时使按钮启用
[英]Making button enabled when javascript return true
问题描述
我正在尝试使用基本验证码制作表格。 目前，因为我是一个新手 HTML 编码器，所以我只在用户单击验证按钮时启用了提交按钮（当它看到返回 true 时它不会启用自身。）我正在努力做到这一点，如果它返回return true我想让按钮启用，并在其他时间禁用。 这是代码的链接： https://codepen.io/pen/GRpVmve
如果有人提供帮助，我将不胜感激。
2 个解决方案
解决方案1
0 已采纳 2020-05-30 09:41:42
删除按钮验证按钮并添加到输入 oninput function
function Check(){ document.getElementById("button2").disabled = true; if(ValidCaptcha()){ document.getElementById("button2").disabled = false; } } function Captcha(){ var alpha = new Array('a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'); var i; for (i=0;i<6;i++){ var a = alpha[Math.floor(Math.random() * alpha.length)]; var b = alpha[Math.floor(Math.random() * alpha.length)]; var c = alpha[Math.floor(Math.random() * alpha.length)]; var d = alpha[Math.floor(Math.random() * alpha.length)]; var e = alpha[Math.floor(Math.random() * alpha.length)]; var f = alpha[Math.floor(Math.random() * alpha.length)]; var g = alpha[Math.floor(Math.random() * alpha.length)]; } var code = a + ' ' + b + ' ' + ' ' + c + ' ' + d + ' ' + e + ' '+ f + ' ' + g; document.getElementById("mainCaptcha").value = code; Check() } function ValidCaptcha(){ var string1 = removeSpaces(document.getElementById('mainCaptcha').value); var string2 = removeSpaces(document.getElementById('txtInput').value); if (string1 == string2){ return true; } else{ return false; } } function removeSpaces(string){ return string.split(' ').join(''); }
<form action="https://www.w3schools.com/action_page.php"> <label for="fname">First name:</label><br> <input type="text" id="fname" name="fname" value="John"><br> <label for="lname">Last name:</label><br> <input type="text" id="lname" name="lname" value="Doe"><br><br> <h3>Gender</h3> <input type="radio" id="male" name="gender" value="male"> <label for="male">Male</label><br> <input type="radio" id="female" name="gender" value="female"> <label for="female">Female</label><br> <input type="radio" id="other" name="gender" value="other"> <label for="other">Other</label> <body onload="Captcha();"> <table> <tr> <h3> Captcha<br /> </td> </tr> <tr> <td> <input type="text" id="mainCaptcha" disabled/> <input type="button" id="refresh" value="Refresh" onclick="Captcha();" /> </td> </tr> <tr> <td> <input type="text"oninput="Check()" name="captcha" id="txtInput"/> </td> </tr> <tr> <td> <input type="submit" id="button2" value="Send" disabled> </td> </tr> </table> </body> </form>
解决方案2
0 2020-05-30 10:50:30
我认为这对你有用......
window.onload=()=>{ document.getElementById('button2').disabled = true; let text = document.getElementById('txtInput').value; Captcha(); } function Captcha(){ var alpha = new Array('a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'); for (i=0;i<6;i++){ var a = alpha[Math.floor(Math.random() * alpha.length)]; var b = alpha[Math.floor(Math.random() * alpha.length)]; var c = alpha[Math.floor(Math.random() * alpha.length)]; var d = alpha[Math.floor(Math.random() * alpha.length)]; var e = alpha[Math.floor(Math.random() * alpha.length)]; var f = alpha[Math.floor(Math.random() * alpha.length)]; var g = alpha[Math.floor(Math.random() * alpha.length)]; } var code = a + ' ' + b + ' ' + ' ' + c + ' ' + d + ' ' + e + ' '+ f + ' ' + g; document.getElementById("mainCaptcha").value = code } function ValidCaptcha(){ var string1 = removeSpaces(document.getElementById('mainCaptcha').value); var string2 = removeSpaces(document.getElementById('txtInput').value); if (string1 == string2){ document.getElementById('button2').disabled = false; } else{ document.getElementById('button2').disabled = true; } } function removeSpaces(string){ return string.split(' ').join(''); } function check(x){ if(x.length<7 || x.length>7){ document.getElementById('button2').disabled = true; } }
<form action="https://www.w3schools.com/action_page.php"> <label for="fname">First name:</label><br> <input type="text" id="fname" name="fname" value="John"><br> <label for="lname">Last name:</label><br> <input type="text" id="lname" name="lname" value="Doe"><br><br> <h3>Gender</h3> <input type="radio" id="male" name="gender" value="male"> <label for="male">Male</label><br> <input type="radio" id="female" name="gender" value="female"> <label for="female">Female</label><br> <input type="radio" id="other" name="gender" value="other"> <label for="other">Other</label> <body onload="Captcha();"> <table> <tr> <h3> Captcha<br /> </td> </tr> <tr> <td> <input type="text" id="mainCaptcha" disabled/> <input type="button" id="refresh" value="Refresh" onclick="Captcha();" /> </td> </tr> <tr> <td> <input type="text" id="txtInput" onkeyup="check(this.value)"/> </td> </tr> <tr> <td> <input id="button1" type="button" value="Verify" onclick="ValidCaptcha()"> <input type="submit" id="button2" value="Send"> </td> </tr> </table> </body> </form>
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