在phonegap中上传之前的图像预览答案

【问题标题】：Image previewing before upload in phonegap在phonegap中上传之前的图像预览
【发布时间】：2016-12-07 06:59:17
【问题描述】：

我知道已经有一些答案可用，但我真的不明白为什么这在我的情况下不起作用。下面是我在远程服务器中上传的代码。我正在使用 phonegap 和 jquery mobile。唯一的问题是图像没有显示在上传到服务器之前的页面。

<html>
<head>
 <title>File Transfer Example</title>
 <script type="text/javascript" src="cordova.js"></script>
 <script type="text/javascript">
     
 function getImage() {
 navigator.camera.getPicture(uploadPhoto, function(message) {
 alert('get picture failed');
 }, {
 quality: 100,
 destinationType: navigator.camera.DestinationType.FILE_URI,
 sourceType: navigator.camera.PictureSourceType.PHOTOLIBRARY
 });
     
}

function uploadPhoto(imageURI) {
document.getElementById("smallImage").src = imageURI
}  
     
function uploadPhoto(imageURI) {
     
   
 var options = new FileUploadOptions();
 options.fileKey = "file";
 options.fileName = imageURI.substr(imageURI.lastIndexOf('/') + 1);
 options.mimeType = "image/jpeg";
 console.log(options.fileName);
 var params = new Object();
 params.value1 = "test";
 params.value2 = "param";
 options.params = params;
 options.chunkedMode = false;
      

var ft = new FileTransfer();
 ft.upload(imageURI, "http://abc.in/my.php",
           
function(result){
console.log(JSON.stringify(result));
     alert('success');
 },   function(error){
 console.log(JSON.stringify(error));
 }, options);
   
 }
    
       
  
 </script>
</head>
<body>
 <button onclick="getImage()">Upload a Photo</button><br>
<img style="width:160px;" id="smallImage" src="" />
</body>
</html>

【问题讨论】：

标签： javascript cordova jquery-mobile phonegap-plugins

【解决方案1】：

imageURI 是一个伪路径，因此它可能在您的本地 HTML 页面上不可用。

上传图片后可以更新图片src。

var ft = new FileTransfer();
 ft.upload(imageURI, "http://abc.in/my.php",

function(result){ 
    var data = JSON.stringify(result);
    var imageSrc = data.src;    // e.g: "http://abc.in/picture.jpg"
    document.getElementById("smallImage").src = imageSrc;
 },

HTTP URL 应该可以工作。

【讨论】：

谢谢它的工作，但我如何每次都为新的 ulpoaded 图像做它，因为它只显示链接的图像，我想在我将图像一一上传到服务器后立即显示图像，请帮助

【解决方案2】：

3 天后，我得到了查询的解决方案，问题是模拟器，用 apk 文件测试下面的代码。不要浪费时间在测试模拟器上。它不会预览图像。下面的代码用于在上传之前预览图像。

<!DOCTYPE html>
<html>
 <head>
<title>Submit form</title>

<script type="text/javascript" charset="utf-8" src="cordova.js"></script>
<script type="text/javascript" charset="utf-8">

var pictureSource;   // picture source
var destinationType; // sets the format of returned value

// Wait for device API libraries to load
//
document.addEventListener("deviceready",onDeviceReady,false);

// device APIs are available
//
function onDeviceReady() {
    pictureSource = navigator.camera.PictureSourceType;
    destinationType = navigator.camera.DestinationType;
}


// Called when a photo is successfully retrieved
//
 function onPhotoURISuccess(imageURI) {

    // Show the selected image
    var smallImage = document.getElementById('smallImage');
    smallImage.style.display = 'block';
    smallImage.src = imageURI;
}


  // A button will call this function
  //
 function getPhoto() {
  // Retrieve image file location from specified source
  navigator.camera.getPicture(onPhotoURISuccess, onFail, { quality: 50,
    sourceType: navigator.camera.PictureSourceType.PHOTOLIBRARY });
  }

    
  function uploadPhoto() {

    //selected photo URI is in the src attribute (we set this on getPhoto)
    var imageURI = document.getElementById('smallImage').getAttribute("src");
    if (!imageURI) {
        alert('Please select an image first.');
        return;
    }

    //set upload options
    var options = new FileUploadOptions();
    options.fileKey = "file";
    options.fileName = imageURI.substr(imageURI.lastIndexOf('/')+1);
    options.mimeType = "image/jpeg";
    options.chunkedMode = false;

    options.params = {
        firstname: document.getElementById("firstname").value,
        lastname: document.getElementById("lastname").value
    }


    options.headers = {
      Connection: "close"
    };

    var ft = new FileTransfer();
    ft.upload(imageURI, encodeURI("http://abc.in/savepng.php"), win, fail,

 options);
}

// Called if something bad happens.
//
function onFail(message) {
  console.log('Failed because: ' + message);alert('success');
}

function win(r) {
    console.log("Code = " + r.responseCode);
    console.log("Response = " + r.response);
    alert("Response =" + r.response);
    console.log("Sent = " + r.bytesSent);
}

function fail(error) {
    alert("An error has occurred: Code = " + error.code);
    console.log("upload error source " + error.source);
    console.log("upload error target " + error.target);
}

</script>
</head>
<body>

    <button onclick="getPhoto();">Select Photo:</button><br>
    <img style="display:none;width:60px;height:60px;" id="smallImage" src="" /><br>

<form id="regform">
    First Name: <input type="text" id="firstname" name="firstname"><br>
    Last Name: <input type="text" id="lastname" name="lastname"><br>
    <input type="button" id="btnSubmit" value="Submit" onclick="uploadPhoto();">
</form>
 </body>
</html>

【讨论】：