android中使用WebView来打开本机的文件选择器支持4.0以上版本

网页上的button定义 <input tyoe="file" />重要：

FILECHOOSER_RESULTCODE = 1

方法一，也是网上能搜到最多的解决方案参考网址：http://stackoverflow.com/questions/4944102/android-webview-file-input-field-filechooser-doesnt-show-up        http://m0s-programming.blogspot.tw/2011/02/file-upload-in-through-webview-on.html

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(requestCode==FILECHOOSER_RESULTCODE) {
if (null == mUploadMessage) return;
Uri result = data == null || resultCode != RESULT_OK ? null
: data.getData();
mUploadMessage.onReceiveValue(result);
mUploadMessage = null;

}
｝

          在WebChromeClient的设定中加入如下代码：

setting.setWebChromeClient(new WebChromeClient() {
// For Android 3.0+
public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType) {
if (mUploadMessage != null) return;
mUploadMessage = uploadMsg;
Intent i = new Intent(Intent.ACTION_GET_CONTENT);
i.addCategory(Intent.CATEGORY_OPENABLE);
i.setType("*/*");
startActivityForResult( Intent.createChooser( i, "File Chooser" ), BrowserActivity.FILECHOOSER_RESULTCODE );
}
// For Android < 3.0
public void openFileChooser(ValueCallback<Uri> uploadMsg) {
openFileChooser( uploadMsg, "" );
}
});
// For Android  > 4.1.1
public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {
openFileChooser(uploadMsg, acceptType);
}

          openFileChooser为隐藏方法。           这样可以实现打开目录上传文件。不过在3.0以后的版本中，如果同样的网页在android自带的浏览器打开会发现，           还有照相，录音的功能，然后直接将生成的图片或音频文件上传，这样就要使用下面的方法。方法二，参考自com.android.browser的源码程式。

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(requestCode==FILECHOOSER_RESULTCODE) {
if (null == mUploadMessage) return;
Uri result = data == null || resultCode != RESULT_OK ? null
: data.getData();
if (result == null && data == null && resultCode == Activity.RESULT_OK) {
File cameraFile = new File(mCameraFilePath);
if (cameraFile.exists()) {
result = Uri.fromFile(cameraFile);
// Broadcast to the media scanner that we have a new photo
// so it will be added into the gallery for the user.
sendBroadcast(
new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, result));
}
}
mUploadMessage.onReceiveValue(result);
mUploadMessage = null;
}
｝

          在WebChromeClient的设定中加入如下代码：      

setting.setWebChromeClient(new WebChromeClient() {
// For Android 3.0+
public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType) {
if (mUploadMessage != null) return;
mUploadMessage = uploadMsg;
startActivityForResult(createDefaultOpenableIntent(),
BrowserActivity.FILECHOOSER_RESULTCODE);
}
}
// For Android < 3.0
public void openFileChooser(ValueCallback<Uri> uploadMsg) {
openFileChooser( uploadMsg, "" );
}
});

     // 重要：原代码漏掉下面定义private String mCameraFilePath;

private Intent createDefaultOpenableIntent() {
// Create and return a chooser with the default OPENABLE
// actions including the camera, camcorder and sound
// recorder where available.
Intent i = new Intent(Intent.ACTION_GET_CONTENT);
i.addCategory(Intent.CATEGORY_OPENABLE);
i.setType("*/*");

Intent chooser = createChooserIntent(createCameraIntent(), createCamcorderIntent(),
createSoundRecorderIntent());
chooser.putExtra(Intent.EXTRA_INTENT, i);
return chooser;
}

private Intent createChooserIntent(Intent... intents) {
Intent chooser = new Intent(Intent.ACTION_CHOOSER);
chooser.putExtra(Intent.EXTRA_INITIAL_INTENTS, intents);
chooser.putExtra(Intent.EXTRA_TITLE, "File Chooser");
return chooser;
}

private Intent createCameraIntent() {

   // 注意：此处代码主要目的是将拍照文件保存在 browser-photos 文件夹下（非系统默认文件夹）// 如不需要这样处理，可以简化代码Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);File externalDataDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM);File cameraDataDir = new File(externalDataDir.getAbsolutePath() +File.separator + "browser-photos");cameraDataDir.mkdirs();mCameraFilePath = cameraDataDir.getAbsolutePath() + File.separator +System.currentTimeMillis() + ".jpg";cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(new File(mCameraFilePath)));return cameraIntent;}private Intent createCamcorderIntent() {return new Intent(MediaStore.ACTION_VIDEO_CAPTURE);}private Intent createSoundRecorderIntent() {return new Intent(MediaStore.Audio.Media.RECORD_SOUND_ACTION);}