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">&nbsp;&nbsp;
  <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

你访问过这个链接吗? http://groups.google.com/group/android-developers/browse_thread/thread/dcaf8b2fdd8a90c4/62d5e2ffef31ebdb

http://moazzam-khan.com/blog/?tag=android-upload-file

http://evgenyg.wordpress.com/2010/05/01/uploading-files-multipart-post-apache/

通过javalib Apache Commons上传文件的简明示例

我想你会从中得到帮助的

其他回答

这是我的工作。也适用于牛轧糖和棉花糖[[

import android.Manifest;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.res.Configuration;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.webkit.ValueCallback;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;

import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class MainActivity extends AppCompatActivity {
    private static final String TAG = MainActivity.class.getSimpleName();
    private final static int FCR = 1;
    WebView webView;
    private String mCM;
    private ValueCallback<Uri> mUM;
    private ValueCallback<Uri[]> mUMA;

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
        super.onActivityResult(requestCode, resultCode, intent);

        if (Build.VERSION.SDK_INT >= 21) {
            Uri[] results = null;

            //Check if response is positive
            if (resultCode == Activity.RESULT_OK) {
                if (requestCode == FCR) {

                    if (null == mUMA) {
                        return;
                    }
                    if (intent == null) {
                        //Capture Photo if no image available
                        if (mCM != null) {
                            results = new Uri[]{Uri.parse(mCM)};
                        }
                    } else {
                        String dataString = intent.getDataString();
                        if (dataString != null) {
                            results = new Uri[]{Uri.parse(dataString)};
                        }
                    }
                }
            }
            mUMA.onReceiveValue(results);
            mUMA = null;
        } else {

            if (requestCode == FCR) {
                if (null == mUM) return;
                Uri result = intent == null || resultCode != RESULT_OK ? null : intent.getData();
                mUM.onReceiveValue(result);
                mUM = null;
            }
        }
    }

    @SuppressLint({"SetJavaScriptEnabled", "WrongViewCast"})
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (Build.VERSION.SDK_INT >= 23 && (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED || ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED)) {
            ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.CAMERA}, 1);
        }

        webView = (WebView) findViewById(R.id.ifView);
        assert webView != null;

        WebSettings webSettings = webView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        webSettings.setAllowFileAccess(true);

        if (Build.VERSION.SDK_INT >= 21) {
            webSettings.setMixedContentMode(0);
            webView.setLayerType(View.LAYER_TYPE_HARDWARE, null);
        } else if (Build.VERSION.SDK_INT >= 19) {
            webView.setLayerType(View.LAYER_TYPE_HARDWARE, null);
        } else if (Build.VERSION.SDK_INT < 19) {
            webView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
        }

        webView.setWebViewClient(new Callback());
        webView.loadUrl("https://infeeds.com/");
        webView.setWebChromeClient(new WebChromeClient() {

            //For Android 3.0+
            public void openFileChooser(ValueCallback<Uri> uploadMsg) {

                mUM = uploadMsg;
                Intent i = new Intent(Intent.ACTION_GET_CONTENT);
                i.addCategory(Intent.CATEGORY_OPENABLE);
                i.setType("*/*");
                MainActivity.this.startActivityForResult(Intent.createChooser(i, "File Chooser"), FCR);
            }

            // For Android 3.0+, above method not supported in some android 3+ versions, in such case we use this
            public void openFileChooser(ValueCallback uploadMsg, String acceptType) {

                mUM = uploadMsg;
                Intent i = new Intent(Intent.ACTION_GET_CONTENT);
                i.addCategory(Intent.CATEGORY_OPENABLE);
                i.setType("*/*");
                MainActivity.this.startActivityForResult(
                        Intent.createChooser(i, "File Browser"),
                        FCR);
            }

            //For Android 4.1+
            public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {

                mUM = uploadMsg;
                Intent i = new Intent(Intent.ACTION_GET_CONTENT);
                i.addCategory(Intent.CATEGORY_OPENABLE);
                i.setType("*/*");
                MainActivity.this.startActivityForResult(Intent.createChooser(i, "File Chooser"), MainActivity.FCR);
            }

            //For Android 5.0+
            public boolean onShowFileChooser(
                    WebView webView, ValueCallback<Uri[]> filePathCallback,
                    WebChromeClient.FileChooserParams fileChooserParams) {

                if (mUMA != null) {
                    mUMA.onReceiveValue(null);
                }

                mUMA = filePathCallback;
                Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                if (takePictureIntent.resolveActivity(MainActivity.this.getPackageManager()) != null) {

                    File photoFile = null;

                    try {
                        photoFile = createImageFile();
                        takePictureIntent.putExtra("PhotoPath", mCM);
                    } catch (IOException ex) {
                        Log.e(TAG, "Image file creation failed", ex);
                    }
                    if (photoFile != null) {
                        mCM = "file:" + photoFile.getAbsolutePath();
                        takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photoFile));
                    } else {
                        takePictureIntent = null;
                    }
                }

                Intent contentSelectionIntent = new Intent(Intent.ACTION_GET_CONTENT);
                contentSelectionIntent.addCategory(Intent.CATEGORY_OPENABLE);
                contentSelectionIntent.setType("*/*");
                Intent[] intentArray;

                if (takePictureIntent != null) {
                    intentArray = new Intent[]{takePictureIntent};
                } else {
                    intentArray = new Intent[0];
                }

                Intent chooserIntent = new Intent(Intent.ACTION_CHOOSER);
                chooserIntent.putExtra(Intent.EXTRA_INTENT, contentSelectionIntent);
                chooserIntent.putExtra(Intent.EXTRA_TITLE, "Image Chooser");
                chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, intentArray);
                startActivityForResult(chooserIntent, FCR);

                return true;
            }
        });
    }

    // Create an image file
    private File createImageFile() throws IOException {

        @SuppressLint("SimpleDateFormat") String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        String imageFileName = "img_" + timeStamp + "_";
        File storageDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
        return File.createTempFile(imageFileName, ".jpg", storageDir);
    }

    @Override
    public boolean onKeyDown(int keyCode, @NonNull KeyEvent event) {

        if (event.getAction() == KeyEvent.ACTION_DOWN) {

            switch (keyCode) {
                case KeyEvent.KEYCODE_BACK:

                    if (webView.canGoBack()) {
                        webView.goBack();
                    } else {
                        finish();
                    }

                    return true;
            }
        }

        return super.onKeyDown(keyCode, event);
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
    }

    public class Callback extends WebViewClient {
        public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
            Toast.makeText(getApplicationContext(), "Failed loading app!", Toast.LENGTH_SHORT).show();
        }
    }
}

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。

在棒棒糖5.0中,谷歌添加了一个官方方法WebChromeClient.onShowFileChooser。它们甚至提供了一种自动生成文件选择器意图的方法,以便它使用输入接受mime类型。

public class MyWebChromeClient extends WebChromeClient {
        // reference to activity instance. May be unnecessary if your web chrome client is member class.
    private MyActivity activity;

    public boolean onShowFileChooser(WebView webView, ValueCallback<Uri[]> filePathCallback, FileChooserParams fileChooserParams) {
        // make sure there is no existing message
        if (myActivity.uploadMessage != null) {
            myActivity.uploadMessage.onReceiveValue(null);
            myActivity.uploadMessage = null;
        }

        myActivity.uploadMessage = filePathCallback;

        Intent intent = fileChooserParams.createIntent();
        try {
            myActivity.startActivityForResult(intent, MyActivity.REQUEST_SELECT_FILE);
        } catch (ActivityNotFoundException e) {
            myActivity.uploadMessage = null;
            Toast.makeText(myActivity, "Cannot open file chooser", Toast.LENGTH_LONG).show();
            return false;
        }

        return true;
    }
}


public class MyActivity extends ... {
    public static final int REQUEST_SELECT_FILE = 100;
    public ValueCallback<Uri[]> uploadMessage;

    protected void onActivityResult(int requestCode, int resultCode, Intent data){
        if (requestCode == REQUEST_SELECT_FILE) {
                if (uploadMessage == null) return;
                uploadMessage.onReceiveValue(WebChromeClient.FileChooserParams.parseResult(resultCode, data));
                uploadMessage = null;
            }
        }
    }
}

对于KitKat之前的Android版本,其他答案中提到的私有方法是有效的。我还没有为KitKat(4.4)找到一个好的解决方案。

Android 8的Kotlin解决方案:

private var mUploadMessage: ValueCallback<Uri>? = null
private var uploadMessage: ValueCallback<Array<Uri>>? = null

常量:

const val FILECHOOSER_RESULTCODE = 1
const val REQUEST_SELECT_FILE = 100

WebView设置:

webView.webChromeClient = object : WebChromeClient() {
        override fun onPermissionRequest(request: PermissionRequest?) {
            Log.d("MainActivity", "onPermissionRequest")
            requestPermission(request)
        }


        // For Android 3.0+
        fun openFileChooser(uploadMsg: ValueCallback<*>, acceptType: String) {
            mUploadMessage = uploadMsg as ValueCallback<Uri>
            val i = Intent(Intent.ACTION_GET_CONTENT)
            i.addCategory(Intent.CATEGORY_OPENABLE)
            i.type = "*/*"
            this@MainActivity.startActivityForResult(
                    Intent.createChooser(i, "File Browser"),
                    FILECHOOSER_RESULTCODE)
        }

        //For Android 4.1
        fun openFileChooser(uploadMsg: ValueCallback<Uri>, acceptType: String, capture: String) {
            mUploadMessage = uploadMsg
            val i = Intent(Intent.ACTION_GET_CONTENT)
            i.addCategory(Intent.CATEGORY_OPENABLE)
            i.type = "image/*"
            this@MainActivity.startActivityForResult(Intent.createChooser(i, "File Chooser"), FILECHOOSER_RESULTCODE)

        }

        protected fun openFileChooser(uploadMsg: ValueCallback<Uri>) {
            mUploadMessage = uploadMsg
            val intent = Intent(Intent.ACTION_GET_CONTENT)
            intent.addCategory(Intent.CATEGORY_OPENABLE)
            intent.type = "*/*"
            startActivityForResult(Intent.createChooser(intent, "File Chooser"), FILECHOOSER_RESULTCODE)
        }

        override fun onShowFileChooser(webView: WebView?, filePathCallback: ValueCallback<Array<Uri>>?, fileChooserParams: FileChooserParams?): Boolean {
            uploadMessage?.onReceiveValue(null)
            uploadMessage = null

            uploadMessage = filePathCallback

            val intent = fileChooserParams!!.createIntent()
            try {
                startActivityForResult(intent, REQUEST_SELECT_FILE)
            } catch (e: ActivityNotFoundException) {
                uploadMessage = null
                Toast.makeText(applicationContext, "Cannot Open File Chooser", Toast.LENGTH_LONG).show()
                return false
            }

            return true
        }

    }

onactivityresult部分:

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        if (requestCode === REQUEST_SELECT_FILE) {
            if (uploadMessage == null)
                return
            print("result code = " + resultCode)
            var results: Array<Uri>? = WebChromeClient.FileChooserParams.parseResult(resultCode, data)
            uploadMessage?.onReceiveValue(results)
            uploadMessage = null
        }
    } else if (requestCode === FILECHOOSER_RESULTCODE) {
        if (null == mUploadMessage)
            return
        // Use MainActivity.RESULT_OK if you're implementing WebView inside Fragment
        // Use RESULT_OK only if you're implementing WebView inside an Activity
        val result = if (intent == null || resultCode !== RESULT_OK) null else intent.data
        mUploadMessage?.onReceiveValue(result)
        mUploadMessage = null
    } else
        Toast.makeText(applicationContext, "Failed to Upload Image", Toast.LENGTH_LONG).show()
}

请注意,我们的意图变量称为“数据”。

我花了将近一个月的时间研究这个问题。一切都失败了。在多个网站中看到的所有代码都不工作。但这里存在最好的解决方案

https://github.com/chiclaim/android-webview-upload-file

步骤

1)点击克隆或下载

2)在本地目录中获取zip fle

3)解压压缩文件

4)开放Android工作室

5)转到文件---->打开>导航到你解压内容的目录。

6)在webView中更改所需的web url。loadUrl(“您的url hre”);在MainActivity.java

7)适用于Android studio 3.4.2版本