我在这里使用了客户端验证码,以下是我的代码。它在我的门户网站上运行良好。
this.canvas = document.getElementById( 'myCanvas' ) as HTMLCanvasElement;
var context = this.canvas.getContext( '2d' );
context.clearRect( 0, 0, this.canvas.width, this.canvas.height );
var alpha = [];
alpha = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H','J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'm', 'n', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
'2', '3', '4', '5', '6', '7', '8', '9'];
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 )];
}
this.captchaCode = a + ' ' + b + ' ' + ' ' + c + ' ' + d + ' ' + e + ' ' + f + ' ' + g;
var ctext = this.captchaCode;
this.loginForm.controls['captcha'].setValue( this.captchaCode.replace( /\s/g, "" ) );
这里是我正在绘制画布图像
var imageObj = new Image();
imageObj.onload = function() {
context.drawImage( imageObj, 0, 0 );
context.font = "24px arial";
context.fillText( ctext, 84, 32 );
};
imageObj.src = 'assets/modules/dummy-assets/common/img/captcha2.jpg';