Sencha Touch提供XHR2配置以使用Ajax和Ajax2开发.
XHR2是xmlHttpRequest级别2，用于从服务器请求数据.对于任何Web应用程序，数据驻留在服务器上，加载页面后，应在Ajax请求的帮助下从服务器访问数据.
Sencha Touch中的XHR2提供进度bar功能，向用户显示为特定请求传输的数据量. XHR2是新添加的，所以我们需要检查浏览器是否支持它.
以下是检查浏览器是否支持XHR2 : 的功能;
if(Ext.feature.has.XHR2){
//这里我们可以编写功能，如果浏览器支持XHR2
}我们甚至可以检查浏览器是否支持使用XHR2的渐进式上传.
if(Ext.feature.has.XHRUploadProgress){
//这里我们可以编写功能，如果浏览器支持渐进式上传
}Sencha Touch中包含各种新的XHR2功能.
| Sr.No | 功能&描述 |
|---|---|
| 1 | XHR2:true 这用于在应用程序中启用和禁用XHR2功能. |
| 2 | Ext.field.File 添加新文件字段以提供更多关于字段类型的实用信息. |
| 3 | Ext.field.FileInput 这提供FileInput. |
| 4 | Ext.progressIndicator 这是为了提供按进度条传输的数据的准确百分比. |
| 5 | xtype:fileinput 创建fileInput类的实例. |
| 6 | xtype:filefield 创建文件类实例. |
| 7 | responseType:value 此参数允许各种类型的响应，如文本，文档，blob等. |
以下是使用和不带参数发送简单ajax请求并使用ajax上传文件的示例.
<!DOCTYPE html>
<html>
<head>
<link href = "https://cdn.sencha.com/touch/sencha-touch-2.4.2/resources/css/sencha-touch.css" rel = "stylesheet" />
<script type = "text/javascript" src = "https://cdn.sencha.com/touch/sencha-touch-2.4.2/sencha-touch-all.js"></script>
<script type = "text/javascript">
Ext.setup({
requires: [ 'Ext.Panel', 'Ext.Button', 'Ext.form.Panel'], onReady: function() {
var request = {
url: 'https://www.it1352.com/sencha_touch/index.htm',
method: 'POST',
xhr2: true,
success: function(response) {
Ext.Msg.alert('Ajax call successful');
},
failure: function(response) {
Ext.Msg.alert('Ajax call failed');
}
};
Ext.Viewport.add({
xtype:"panel",
layout:"vbox",
fullscreen:true,
items: [
{
xtype:"button",
text: "Ajax",
ui: 'confirm',
handler: function(){
Ext.Ajax.request(request);
}
}
]
});
}
});
</script>
</head>
<body>
</body>
</html>上面的示例显示了成功的ajax调用，因为提到的URL是正确的。 在此示例中，我们没有传递任何参数，只是一个简单的ajax请求，它命中了所提到的URL。
如果您在开发人员工具中使用chrome浏览器，请导航至"网络"部分，您可以看到正在发送的请求和得到的响应。
<!DOCTYPE html>
<html>
<head>
<link href = "https://cdn.sencha.com/touch/sencha-touch-2.4.2/resources/css/sencha-touch.css" rel = "stylesheet" />
<script type = "text/javascript" src = "https://cdn.sencha.com/touch/sencha-touch-2.4.2/sencha-touch-all.js"></script>
<script type = "text/javascript">
Ext.setup({
requires: [
'Ext.Panel',
'Ext.Button',
'Ext.form.Panel'
],
onReady: function() {
var request = {
url: 'https://www.it1352.com/sencha_touch/indexx.htm',
method: 'POST',
xhr2: true,
success: function(response) {
Ext.Msg.alert('Ajax call successful');
},
failure: function(response) {
Ext.Msg.alert('Ajax call failed');
}
};
Ext.Viewport.add({
xtype:"panel",
layout:"vbox",
fullscreen:true,
items: [
{
xtype:"button",
text: "Ajax",
ui: 'confirm',
handler: function(){
Ext.Ajax.request(request);
}
}
]
});
}
});
</script>
</head>
<body>
</body>
</html>在上面的示例中，仅为了说明ajax失败的工作原理，我们提到了错误的URL。 比较此示例和上一个示例，您会发现区别。
<!DOCTYPE html>
<html>
<head>
<link href = "https://cdn.sencha.com/touch/sencha-touch-2.4.2/resources/css/sencha-touch.css" rel = "stylesheet" />
<script type = "text/javascript" src = "https://cdn.sencha.com/touch/sencha-touch-2.4.2/sencha-touch-all.js"></script>
<script type = "text/javascript">
Ext.setup({
requires: [
'Ext.Panel',
'Ext.Button',
'Ext.form.Panel'
],
onReady: function() {
var formData = new FormData();
formData.append("firstName", "Hi");
formData.append("lastName", "Reader");
// Request will be sent as part of the payload instead of standard post data
var request = {
url: 'https://www.it1352.com/sencha_touch/sencha_json.php',
method: 'POST',
xhr2: true,
data: formData,
success: function(response) {
var out = Ext.getCmp("output");
response = Ext.JSON.decode(response.responseText, true);
Ext.Msg.alert(response.message);
},
failure: function(response) {
var out = Ext.getCmp("output");
Ext.Msg.alert('Ajax failed!');
}
};
Ext.Viewport.add({
xtype:"panel",
layout:"vbox",
fullscreen:true,
items: [
{
xtype:"button",
text: "Ajax",
ui: 'confirm',
handler: function(){
Ext.Ajax.request(request);
}
}
]
});
}
});
</script>
</head>
<body>
</body>
</html>在此示例中，我们使用ajax调用的data属性将参数与ajax一起传递。
<!DOCTYPE html>
<html>
<head>
<link href = "https://cdn.sencha.com/touch/sencha-touch-2.4.2/resources/css/sencha-touch.css" rel = "stylesheet" />
<script type = "text/javascript" src = "https://cdn.sencha.com/touch/sencha-touch-2.4.2/sencha-touch-all.js"></script>
<script type = "text/javascript">
Ext.setup({
requires: [
'Ext.Panel',
'Ext.MessageBox',
'Ext.Button',
'Ext.ProgressIndicator',
'Ext.form.Panel',
'Ext.field.FileInput'
],
onReady: function() {
var progressIndicator = Ext.create("Ext.ProgressIndicator", {
loadingText: "Uploading: {percent}%"
});
var request = {
url: 'https://www.it1352.com/sencha_touch/sencha_json.php',
method: 'POST',
xhr2: true,
progress:progressIndicator,
success: function(response) {
Ext.Msg.alert('File uploaded successfully.');
},
failure: function(response) {
Ext.Msg.alert('File upload failed.');
}
};
Ext.Viewport.add(progressIndicator);
Ext.Viewport.add({
xtype:"panel",
layout:"vbox",
fullscreen:true,
items: [
{
xtype:"fileinput",
accept:"image/jpeg"
},
{
xtype:"button",
text: "Upload",
ui: 'confirm',
handler: function(){
var input = Ext.Viewport.down("fileinput").input;
var files = input.dom.files;
if (files.length) {
request.binaryData = files[0];
Ext.Ajax.request(request);
}else {
Ext.Msg.alert("Please Select a JPG");
}
}
}
]
});
}
});
</script>
</head>
<body>
</body>
</html>此示例显示如何使用ajax调用上传数据.在此示例中，我们使用进度条指示器显示上载文件时的进度.
