我还有一个主意。

提供下载文件的PHP文件的URL。 然后你必须通过ajax触发相同的URL，我检查了这第二个请求只在你的第一个请求完成下载文件后才给出响应。所以你可以得到它的事件。

它正在通过ajax处理同样的第二个请求。

我还有一个主意。

提供下载文件的PHP文件的URL。 然后你必须通过ajax触发相同的URL，我检查了这第二个请求只在你的第一个请求完成下载文件后才给出响应。所以你可以得到它的事件。

它正在通过ajax处理同样的第二个请求。

请核对一下。它是完整的Ajax请求代码。

$('#foo').submit(function(event) {
    // Get the form data
    // There are many ways to get this data using jQuery (you
    // can use the class or id also)
    var formData = $('#foo').serialize();
    var url = 'URL of the request';

    // Process the form.
    $.ajax({
        type        : 'POST',   // Define the type of HTTP verb we want to use
        url         : 'url/',   // The URL where we want to POST
        data        : formData, // Our data object
        dataType    : 'json',   // What type of data do we expect back.
        beforeSend : function() {

            // This will run before sending an Ajax request.
            // Do whatever activity you want, like show loaded.
        },
        success:function(response){
            var obj = eval(response);
            if(obj)
            {
                if(obj.error==0){
                    alert('success');
                }
                else{
                    alert('error');
                }
            }
        },
        complete : function() {
            // This will run after sending an Ajax complete
        },
        error:function (xhr, ajaxOptions, thrownError){
            alert('error occured');
            // If any error occurs in request
        }
    });

    // Stop the form from submitting the normal way
    // and refreshing the page
    event.preventDefault();
});

我想分享一个详细的方法，如何张贴与PHP + Ajax以及错误抛出返回失败。

首先，创建两个文件，例如form.php和process.php。

我们将首先创建一个表单，然后使用jQuery .ajax()方法提交。其余的将在评论中解释。

form.php

<form method="post" name="postForm">
    <ul>
        <li>
            <label>Name</label>
            <input type="text" name="name" id="name" placeholder="Bruce Wayne">
            <span class="throw_error"></span>
            <span id="success"></span>
       </li>
   </ul>
   <input type="submit" value="Send" />
</form>

使用jQuery客户端验证表单并将数据传递给process.php。

$(document).ready(function() {
    $('form').submit(function(event) { //Trigger on form submit
        $('#name + .throw_error').empty(); //Clear the messages first
        $('#success').empty();

        //Validate fields if required using jQuery

        var postForm = { //Fetch form data
            'name'     : $('input[name=name]').val() //Store name fields value
        };

        $.ajax({ //Process the form using $.ajax()
            type      : 'POST', //Method type
            url       : 'process.php', //Your form processing file URL
            data      : postForm, //Forms name
            dataType  : 'json',
            success   : function(data) {
                            if (!data.success) { //If fails
                                if (data.errors.name) { //Returned if any error from process.php
                                    $('.throw_error').fadeIn(1000).html(data.errors.name); //Throw relevant error
                                }
                            }
                            else {
                                    $('#success').fadeIn(1000).append('<p>' + data.posted + '</p>'); //If successful, than throw a success message
                                }
                            }
        });
        event.preventDefault(); //Prevent the default submit
    });
});

现在我们来看看process.php

$errors = array(); //To store errors
$form_data = array(); //Pass back the data to `form.php`

/* Validate the form on the server side */
if (empty($_POST['name'])) { //Name cannot be empty
    $errors['name'] = 'Name cannot be blank';
}

if (!empty($errors)) { //If errors in validation
    $form_data['success'] = false;
    $form_data['errors']  = $errors;
}
else { //If not, process the form, and return true on success
    $form_data['success'] = true;
    $form_data['posted'] = 'Data Was Posted Successfully';
}

//Return the data back to form.php
echo json_encode($form_data);

项目文件可以从http://projects.decodingweb.com/simple_ajax_form.zip下载。

ajax的基本用法是这样的:

HTML:

<form id="foo">
    <label for="bar">A bar</label>
    <input id="bar" name="bar" type="text" value="" />

    <input type="submit" value="Send" />
</form>

jQuery:

// Variable to hold request
var request;

// Bind to the submit event of our form
$("#foo").submit(function(event){

    // Prevent default posting of form - put here to work in case of errors
    event.preventDefault();

    // Abort any pending request
    if (request) {
        request.abort();
    }
    // setup some local variables
    var $form = $(this);

    // Let's select and cache all the fields
    var $inputs = $form.find("input, select, button, textarea");

    // Serialize the data in the form
    var serializedData = $form.serialize();

    // Let's disable the inputs for the duration of the Ajax request.
    // Note: we disable elements AFTER the form data has been serialized.
    // Disabled form elements will not be serialized.
    $inputs.prop("disabled", true);

    // Fire off the request to /form.php
    request = $.ajax({
        url: "/form.php",
        type: "post",
        data: serializedData
    });

    // Callback handler that will be called on success
    request.done(function (response, textStatus, jqXHR){
        // Log a message to the console
        console.log("Hooray, it worked!");
    });

    // Callback handler that will be called on failure
    request.fail(function (jqXHR, textStatus, errorThrown){
        // Log the error to the console
        console.error(
            "The following error occurred: "+
            textStatus, errorThrown
        );
    });

    // Callback handler that will be called regardless
    // if the request failed or succeeded
    request.always(function () {
        // Reenable the inputs
        $inputs.prop("disabled", false);
    });

});

注意:从jQuery 1.8开始，.success()， .error()和.complete()已被弃用，取而代之的是.done()， .fail()和.always()。

注意:请记住，上面的代码段必须在DOM ready之后完成，因此应该将其放在$(document).ready()处理程序中(或使用$()简写)。

提示:你可以像这样链接回调处理程序:$.ajax().done().fail().always();

PHP(即form.php):

// You can access the values posted by jQuery.ajax
// through the global variable $_POST, like this:
$bar = isset($_POST['bar']) ? $_POST['bar'] : null;

注意:总是消毒发布的数据，以防止注入和其他恶意代码。

你也可以在上面的JavaScript代码中使用。post来代替。ajax:

$.post('/form.php', serializedData, function(response) {
    // Log the response to the console
    console.log("Response: "+response);
});

注意:上面的JavaScript代码适用于jQuery 1.8及更高版本，但它应该适用于jQuery 1.5之前的版本。

在提交前和提交成功后处理Ajax错误和加载器显示了一个警报引导框的示例:

var formData = formData;

$.ajax({
    type: "POST",
    url: url,
    async: false,
    data: formData, // Only input
    processData: false,
    contentType: false,
    xhr: function ()
    {
        $("#load_consulting").show();
        var xhr = new window.XMLHttpRequest();

        // Upload progress
        xhr.upload.addEventListener("progress", function (evt) {
            if (evt.lengthComputable) {
                var percentComplete = (evt.loaded / evt.total) * 100;
                $('#addLoad .progress-bar').css('width', percentComplete + '%');
            }
        }, false);

        // Download progress
        xhr.addEventListener("progress", function (evt) {
            if (evt.lengthComputable) {
                var percentComplete = evt.loaded / evt.total;
            }
        }, false);
        return xhr;
    },
    beforeSend: function (xhr) {
        qyuraLoader.startLoader();
    },
    success: function (response, textStatus, jqXHR) {
        qyuraLoader.stopLoader();
        try {
            $("#load_consulting").hide();

            var data = $.parseJSON(response);
            if (data.status == 0)
            {
                if (data.isAlive)
                {
                    $('#addLoad .progress-bar').css('width', '00%');
                    console.log(data.errors);
                    $.each(data.errors, function (index, value) {
                        if (typeof data.custom == 'undefined') {
                            $('#err_' + index).html(value);
                        }
                        else
                        {
                            $('#err_' + index).addClass('error');

                            if (index == 'TopError')
                            {
                                $('#er_' + index).html(value);
                            }
                            else {
                                $('#er_TopError').append('<p>' + value + '</p>');
                            }
                        }
                    });
                    if (data.errors.TopError) {
                        $('#er_TopError').show();
                        $('#er_TopError').html(data.errors.TopError);
                        setTimeout(function () {
                            $('#er_TopError').hide(5000);
                            $('#er_TopError').html('');
                        }, 5000);
                    }
                }
                else
                {
                    $('#headLogin').html(data.loginMod);
                }
            } else {
                //document.getElementById("setData").reset();
                $('#myModal').modal('hide');
                $('#successTop').show();
                $('#successTop').html(data.msg);
                if (data.msg != '' && data.msg != "undefined") {

                    bootbox.alert({closeButton: false, message: data.msg, callback: function () {
                            if (data.url) {
                                window.location.href = '<?php echo site_url() ?>' + '/' + data.url;
                            } else {
                                location.reload(true);
                            }
                        }});
                } else {
                    bootbox.alert({closeButton: false, message: "Success", callback: function () {
                        if (data.url) {
                            window.location.href = '<?php echo site_url() ?>' + '/' + data.url;
                        } else {
                            location.reload(true);
                        }
                    }});
                }

            }
        }
        catch (e) {
            if (e) {
                $('#er_TopError').show();
                $('#er_TopError').html(e);
                setTimeout(function () {
                    $('#er_TopError').hide(5000);
                    $('#er_TopError').html('');
                }, 5000);
            }
        }
    }
});