javascript - Casperjs Casper错误: Cannot dispatch mousedown event on nonexistent selector:

Question

我是 Casperjs 的新手，我试图让这个脚本复制一些文本，但即使我有正确的路径，它也无法找到搜索按钮。我之前能够单击脚本中的所有按钮，但它在该行给出了错误:

    casper.wait(2000, function () {
        casper.click(x('//*[@id="SRCHBTN"]'));     <----Error here
        casper.capture('CurrentScreen.png');
    });


CasperError: Cannot dispatch mousedown event on nonexistent selector:

这是代码:

var casper = require('casper').create();

var x = require('casper').selectXPath;

casper.userAgent('Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)');

casper.start('url');

casper.then(function () {
    this.sendKeys('user', 'user');
    this.sendKeys('pswd', 'pass');
    console.log('Entering Data');

});

casper.thenClick(x('//*[@id="login"]/table[1]/tbody/tr[3]/td[2]/input'), function () {
    console.log('Logging in..');
});

casper.wait(2000, function () {
    casper.click(x('//*[@id="SRCH_LINK"]/a'));
});

casper.wait(2000, function () {
    casper.click(x('//*[@id="SRCHBTN"]'));
    casper.capture('CurrentScreen.png');
});






casper.wait(4000, function () {
    casper.click(x('//*[@id="TITLE_HL$0"]'));
casper.wait(2000, function() {

    //this is pop up window section

    casper.waitForPopup(/popup\.html$/, function () {
        this.test.assertEquals(this.popups.length, 1);
    });

    // this will set the popup DOM as the main active one only for time the
    // step closure being executed
    casper.withPopup(/popup\.html$/, function () {
        this.test.assertTitle('Job Details - Google Chrome');
        var targetText = casper.fetchText('#DESCR');
        console.log(targetText);
    });

    // next step will automatically revert the current page to the initial one
    casper.then(function () {
        this.test.assertTitle('Main page title');
    });





    });
});


casper.run();

Answer 1

如果预期元素的存在依赖于异步调用，则等待 2 秒并不能保证调用完成。您应该使用 waitForSelector() 函数，而不是 wait():

casper.waitForSelector(x('//*[@id="SRCHBTN"]'), function () {
    casper.click(x('//*[@id="SRCHBTN"]'));
    casper.capture('CurrentScreen.png'); });
});