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

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);
}

其他回答

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

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”。

蜂窝(API 11)到Android 11的工作方法

由swati vishnoi更新,这适用于派和以上

static WebView mWebView;
private ValueCallback<Uri> mUploadMessage;
public ValueCallback<Uri[]> uploadMessage;
public static final int REQUEST_SELECT_FILE = 100;
private final static int FILECHOOSER_RESULTCODE = 1;

修改onActivityResult ()

@Override
public void onActivityResult(int requestCode, int resultCode, Intent intent)
{
    if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
    {
        if (requestCode == REQUEST_SELECT_FILE)
        {
            if (uploadMessage == null)
                return;
            uploadMessage.onReceiveValue(WebChromeClient.FileChooserParams.parseResult(resultCode, intent));
            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
        Uri result = intent == null || resultCode != MainActivity.RESULT_OK ? null : intent.getData();
        mUploadMessage.onReceiveValue(result);
        mUploadMessage = null;
    }
    else
        Toast.makeText(getActivity().getApplicationContext(), "Failed to Upload Image", Toast.LENGTH_LONG).show();
}

现在在onCreate()或onCreateView()中粘贴以下代码

    WebSettings mWebSettings = mWebView.getSettings();
    mWebSettings.setJavaScriptEnabled(true);
    mWebSettings.setSupportZoom(false);
    mWebSettings.setAllowFileAccess(true);
    mWebSettings.setAllowContentAccess(true);

mWebView.setWebChromeClient(new WebChromeClient()
{
    // For 3.0+ Devices (Start)
    // onActivityResult attached before constructor
    protected void openFileChooser(ValueCallback uploadMsg, String acceptType)
    {
        mUploadMessage = uploadMsg;
        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
        i.addCategory(Intent.CATEGORY_OPENABLE);
        i.setType("image/*");
        startActivityForResult(Intent.createChooser(i, "File Browser"), FILECHOOSER_RESULTCODE);
    }
   

    // For Lollipop 5.0+ Devices
    public boolean onShowFileChooser(WebView mWebView, ValueCallback<Uri[]> filePathCallback, WebChromeClient.FileChooserParams fileChooserParams)
    {
        if (uploadMessage != null) {
            uploadMessage.onReceiveValue(null);
            uploadMessage = null;
        }

        uploadMessage = filePathCallback;

        Intent intent = fileChooserParams.createIntent();
        try
        {
            startActivityForResult(intent, REQUEST_SELECT_FILE);
        } catch (ActivityNotFoundException e)
        {
            uploadMessage = null;
            Toast.makeText(getActivity().getApplicationContext(), "Cannot Open File Chooser", Toast.LENGTH_LONG).show();
            return false;
        }
        return true;
    }
    
    //For Android 4.1 only
    protected void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture)
    {
        mUploadMessage = uploadMsg;
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.addCategory(Intent.CATEGORY_OPENABLE);
        intent.setType("image/*");
        startActivityForResult(Intent.createChooser(intent, "File Browser"), FILECHOOSER_RESULTCODE);
    }

    protected void openFileChooser(ValueCallback<Uri> uploadMsg)
    {
        mUploadMessage = uploadMsg;
        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
        i.addCategory(Intent.CATEGORY_OPENABLE);
        i.setType("image/*");
        startActivityForResult(Intent.createChooser(i, "File Chooser"), FILECHOOSER_RESULTCODE);
    }
});

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