我一直在努力从WebView上传文件。我在谷歌上搜索并实施了所有建议的解决方案(例如这篇SO帖子)，但没有一个可行。
我有一个HTML页面与以下代码上传文件。
<form method="POST" enctype="multipart/form-data">
File to upload: <input type="file" name="uploadfile">
<input type="submit" value="Press to Upload..."> to upload the file!
</form>
它在桌面浏览器如Firefox和内置浏览器中运行良好 的模拟器/ AVD，即，当我点击“浏览…”按钮渲染 元素，浏览器打开一个对话框 框，在那里我可以选择一个文件上传。
然而，在android 3.0模拟器/ AVD中，当我点击“选择” 文件”，什么都没有发生，没有文件对话框被打开!
当前回答
在奇巧，你可以使用存储访问框架。
存储访问框架/编写客户端应用程序
其他回答
我是android的新手，在这方面也很吃力。根据谷歌参考指南WebView。
默认情况下，WebView不提供类似浏览器的小部件 启用JavaScript和网页错误被忽略。如果你的目标是 只是显示一些HTML作为你的UI的一部分，这可能是好的; 除了阅读，用户不需要与网页进行交互， 网页也不需要与用户交互。如果你真的 想要一个成熟的web浏览器，那么您可能需要调用 浏览器应用程序的URL意图，而不是显示它与 WebView。
我在mainactivity .java中执行的示例代码。
Uri uri = Uri.parse("https://www.example.com");
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent);
Excuted
package example.com.myapp;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.content.Intent;
import android.net.Uri;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Uri uri = Uri.parse("http://www.example.com/");
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent);
getSupportActionBar().hide();
}}
我发现我需要3个接口定义，以处理不同版本的android。
public void openFileChooser(ValueCallback < Uri > uploadMsg) {
mUploadMessage = uploadMsg;
Intent i = new Intent(Intent.ACTION_GET_CONTENT);
i.addCategory(Intent.CATEGORY_OPENABLE);
i.setType("image/*");
FreeHealthTrack.this.startActivityForResult(Intent.createChooser(i, "Image Chooser"), FILECHOOSER_RESULTCODE);
}
public void openFileChooser(ValueCallback < Uri > uploadMsg, String acceptType) {
openFileChooser(uploadMsg);
}
public void openFileChooser(ValueCallback < Uri > uploadMsg, String acceptType, String capture) {
openFileChooser(uploadMsg);
}
我发现有必要在Android 4.1中定义公共void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture)。然后我采用了米歇尔·奥利弗的解决方案。
谷歌自己的浏览器为这个问题提供了一个全面的解决方案，它保证了自己的类:
openFileChooser在Android 4.0.4中的实现
android4.0.4中的UploadHandler类
我实际上设法让文件选择器出现在奇巧，选择一个图像，并在活动结果中获得文件路径，但唯一的一件事，我不能“修复”(造成这种工作方式)是使输入字段填写文件数据。
有人知道如何从活动中访问输入字段吗?我使用这个例子注释。只是这最后一块，在墙上的最后一块砖，我只是把到正确的地方(虽然我可以触发图像文件直接从代码上传。
UPDATE # 1
我不是硬核Android开发，所以我会在新手级别上显示代码。我在已经存在的活动中创建一个新的活动
清单的一部分
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<application android:label="TestApp">
<activity android:name=".BrowseActivity"></activity>
</application>
我从这个示例答案创建我的BrowseActivity类。WebChromeClient()实例基本上看起来是一样的，除了最后一部分，触发选择器UI部分…
private final static int FILECHOOSER_RESULTCODE=1;
private final static int KITKAT_RESULTCODE = 2;
...
// The new WebChromeClient() looks pretty much the same, except one piece...
WebChromeClient chromeClient = new WebChromeClient(){
// For Android 3.0+
public void openFileChooser(ValueCallback<Uri> uploadMsg) { /* Default code */ }
// For Android 3.0+
public void openFileChooser( ValueCallback uploadMsg, String acceptType ) { /* Default code */ }
//For Android 4.1, also default but it'll be as example
public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture){
mUploadMessage = uploadMsg;
Intent i = new Intent(Intent.ACTION_GET_CONTENT);
i.addCategory(Intent.CATEGORY_OPENABLE);
i.setType("*/*");
BrowseActivity.this.startActivityForResult(Intent.createChooser(i, "File Chooser"), BrowseActivity.FILECHOOSER_RESULTCODE);
}
// The new code
public void showPicker( ValueCallback<Uri> uploadMsg ){
// Here is part of the issue, the uploadMsg is null since it is not triggered from Android
mUploadMessage = uploadMsg;
Intent i = new Intent(Intent.ACTION_GET_CONTENT);
i.addCategory(Intent.CATEGORY_OPENABLE);
i.setType("*/*");
BrowseActivity.this.startActivityForResult(Intent.createChooser(i, "File Chooser"), BrowseActivity.KITKAT_RESULTCODE);
}}
还有更多的东西
web = new WebView(this);
// Notice this part, setting chromeClient as js interface is just lazy
web.getSettings().setJavaScriptEnabled(true);
web.addJavascriptInterface(chromeClient, "jsi" );
web.getSettings().setAllowFileAccess(true);
web.getSettings().setAllowContentAccess(true);
web.clearCache(true);
web.loadUrl( "http://as3breeze.com/upload.html" );
web.setWebViewClient(new myWebClient());
web.setWebChromeClient(chromeClient);
@Override protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
Log.d("Result", "("+requestCode+ ") - (" +resultCode + ") - (" + intent + ") - " + mUploadMessage);
if (null == intent) return;
Uri result = null;
if(requestCode==FILECHOOSER_RESULTCODE)
{
Log.d("Result","Old android");
if (null == mUploadMessage) return;
result = intent == null || resultCode != RESULT_OK ? null : intent.getData();
mUploadMessage.onReceiveValue(result);
mUploadMessage = null;
} else if (requestCode == KITKAT_RESULTCODE) {
Log.d("Result","Kitkat android");
result = intent.getData();
final int takeFlags = intent.getFlags() & (Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
String path = getPath( this, result);
File selectedFile = new File(path);
//I used you example with a bit of editing so thought i would share, here i added a method to upload the file to the webserver
File selectedFile = new File(path);
UploadFile(selectedFile);
//mUploadMessage.onReceiveValue( Uri.parse(selectedFile.toString()) );
// Now we have the file but since mUploadMessage was null, it gets errors
}
}
public void UploadFile(File selectedFile)
{
Random rnd = new Random();
String sName = "File" + rnd.nextInt(999999) + selectedFile.getAbsolutePath().substring(selectedFile.getAbsolutePath().lastIndexOf("."));
UploadedFileName = sName;
uploadFile = selectedFile;
if (progressBar != null && progressBar.isShowing())
{
progressBar.dismiss();
}
// prepare for a progress bar dialog
progressBar = new ProgressDialog(mContext);
progressBar.setCancelable(true);
progressBar.setMessage("Uploading File");
progressBar.setProgressStyle(ProgressDialog.STYLE_SPINNER);
progressBar.show();
new Thread() {
public void run()
{
int serverResponseCode;
String serverResponseMessage;
HttpURLConnection connection = null;
DataOutputStream outputStream = null;
DataInputStream inputStream = null;
String pathToOurFile = uploadFile.getAbsolutePath();
String urlServer = "http://serveraddress/Scripts/UploadHandler.php?name" + UploadedFileName;
String lineEnd = "\r\n";
String twoHyphens = "--";
String boundary = "*****";
int bytesRead, bytesAvailable, bufferSize;
byte[] buffer;
int maxBufferSize = 1*1024*1024;
try
{
FileInputStream fileInputStream = new FileInputStream(uploadFile);
URL url = new URL(urlServer);
connection = (HttpURLConnection) url.openConnection();
Log.i("File", urlServer);
// Allow Inputs & Outputs.
connection.setDoInput(true);
connection.setDoOutput(true);
connection.setUseCaches(false);
// Set HTTP method to POST.
connection.setRequestMethod("POST");
connection.setRequestProperty("Connection", "Keep-Alive");
connection.setRequestProperty("Content-Type", "multipart/form-data;boundary="+boundary);
Log.i("File", "Open conn");
outputStream = new DataOutputStream( connection.getOutputStream() );
outputStream.writeBytes(twoHyphens + boundary + lineEnd);
outputStream.writeBytes("Content-Disposition: form-data; name=\"uploadedfile\";filename=\"" + pathToOurFile +"\"" + lineEnd);
outputStream.writeBytes(lineEnd);
Log.i("File", "write bytes");
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
buffer = new byte[bufferSize];
Log.i("File", "available: " + fileInputStream.available());
// Read file
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
Log.i("file", "Bytes Read: " + bytesRead);
while (bytesRead > 0)
{
outputStream.write(buffer, 0, bufferSize);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
}
outputStream.writeBytes(lineEnd);
outputStream.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
// Responses from the server (code and message)
serverResponseCode = connection.getResponseCode();
serverResponseMessage = connection.getResponseMessage();
Log.i("file repsonse", serverResponseMessage);
//once the file is uploaded call a javascript function to verify the user wants to save the image
progressBar.dismiss();
runOnUiThread(new Runnable()
{
@Override
public void run()
{
Log.i("start", "File name: " + UploadedFileName);
WebView myWebView = (WebView) findViewById(R.id.webview);
myWebView.loadUrl("javascript:CheckImage('" + UploadedFileName + "')");
}
});
fileInputStream.close();
outputStream.flush();
outputStream.close();
}
catch (Exception ex)
{
Log.i("exception", "Error: " + ex.toString());
}
}
}.start();
}
最后，一些更多的代码来获得实际的文件路径，在SO上找到的代码，我在评论中添加了post url，这样作者就可以为他的工作获得学分。
/**
* Get a file path from a Uri. This will get the the path for Storage Access
* Framework Documents, as well as the _data field for the MediaStore and
* other file-based ContentProviders.
*
* @param context The context.
* @param uri The Uri to query.
* @author paulburke
* @source https://stackoverflow.com/a/20559175
*/
@TargetApi(Build.VERSION_CODES.KITKAT)
public static String getPath(final Context context, final Uri uri) {
final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
// DocumentProvider
if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
// ExternalStorageProvider
if (isExternalStorageDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
if ("primary".equalsIgnoreCase(type)) {
return Environment.getExternalStorageDirectory() + "/" + split[1];
}
// TODO handle non-primary volumes
}
// DownloadsProvider
else if (isDownloadsDocument(uri)) {
final String id = DocumentsContract.getDocumentId(uri);
final Uri contentUri = ContentUris.withAppendedId(
Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
return getDataColumn(context, contentUri, null, null);
}
// MediaProvider
else if (isMediaDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
Uri contentUri = null;
if ("image".equals(type)) {
contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
} else if ("video".equals(type)) {
contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
} else if ("audio".equals(type)) {
contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
}
final String selection = "_id=?";
final String[] selectionArgs = new String[] {
split[1]
};
return getDataColumn(context, contentUri, selection, selectionArgs);
}
}
// MediaStore (and general)
else if ("content".equalsIgnoreCase(uri.getScheme())) {
return getDataColumn(context, uri, null, null);
}
// File
else if ("file".equalsIgnoreCase(uri.getScheme())) {
return uri.getPath();
}
return null;
}
/**
* Get the value of the data column for this Uri. This is useful for
* MediaStore Uris, and other file-based ContentProviders.
*
* @param context The context.
* @param uri The Uri to query.
* @param selection (Optional) Filter used in the query.
* @param selectionArgs (Optional) Selection arguments used in the query.
* @return The value of the _data column, which is typically a file path.
* @source https://stackoverflow.com/a/20559175
*/
public static String getDataColumn(Context context, Uri uri, String selection,
String[] selectionArgs) {
Cursor cursor = null;
final String column = "_data";
final String[] projection = {
column
};
try {
cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
null);
if (cursor != null && cursor.moveToFirst()) {
final int column_index = cursor.getColumnIndexOrThrow(column);
return cursor.getString(column_index);
}
} finally {
if (cursor != null)
cursor.close();
}
return null;
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is ExternalStorageProvider.
* @source https://stackoverflow.com/a/20559175
*/
public static boolean isExternalStorageDocument(Uri uri) {
return "com.android.externalstorage.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is DownloadsProvider.
* @source https://stackoverflow.com/a/20559175
*/
public static boolean isDownloadsDocument(Uri uri) {
return "com.android.providers.downloads.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is MediaProvider.
* @source https://stackoverflow.com/a/20559175
*/
public static boolean isMediaDocument(Uri uri) {
return "com.android.providers.media.documents".equals(uri.getAuthority());
}
最后，HTML页面需要触发showPicker的新方法(特别是在A4.4上时)
<form id="form-upload" method="post" enctype="multipart/form-data">
<input id="fileupload" name="fileupload" type="file" onclick="javascript:prepareForPicker();"/>
</form>
<script type="text/javascript">
function getAndroidVersion() {
var ua = navigator.userAgent;
var match = ua.match(/Android\s([0-9\.]*)/);
return match ? match[1] : false;
};
function prepareForPicker(){
if(getAndroidVersion().indexOf("4.4") != -1){
window.jsi.showPicker();
return false;
}
}
function CheckImage(name)
{
//Check to see if user wants to save I used some ajax to save the file if necesarry
}
</script>
