要在Android Webview应用程序中启用文件上传功能，可以按照以下步骤进行操作：

1.在AndroidManifest.xml文件中添加以下代码以获取WRITE_EXTERNAL_STORAGE权限：

2.在Webview设置中启用JavaScript：

webView.getSettings().setJavaScriptEnabled(true);

3.为Webview设置WebChromeClient：

webView.setWebChromeClient(new WebChromeClient() { //文件选择器数据 public void openFileChooser(ValueCallback uploadMsg) {

    //创建包含传递文件URI的意图
    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
    intent.addCategory(Intent.CATEGORY_OPENABLE);
    intent.setType("*/*");

    //启动文件选择器
    startActivityForResult(Intent.createChooser(intent, "File Chooser"), FILECHOOSER_RESULTCODE);
}

// For Android  >= 3.0
public void openFileChooser(ValueCallback uploadMsg, String acceptType) {
    openFileChooser(uploadMsg, acceptType, "");
}

// For Android  >= 4.1
public void openFileChooser(ValueCallback uploadMsg, String acceptType, String capture) {
    mUploadMessage = uploadMsg;
    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
    intent.addCategory(Intent.CATEGORY_OPENABLE);
    intent.setType("*/*");
    startActivityForResult(Intent.createChooser(intent, "File Chooser"), FILECHOOSER_RESULTCODE);
}

// For Android > 5.0
@Override
public boolean onShowFileChooser(WebView webView, ValueCallback filePathCallback, WebChromeClient.FileChooserParams fileChooserParams) {
    mFilePathCallback = filePathCallback;
    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
    intent.addCategory(Intent.CATEGORY_OPENABLE);
    intent.setType("*/*");
    startActivityForResult(Intent.createChooser(intent, "File Chooser"), FILECHOOSER_RESULTCODE);
    return true;
}

});

4.在onActivityResult方法中处理文件选择器意图：

@Override public void onActivityResult(int requestCode, int resultCode, Intent intent) { if (requestCode == FILECHOOSER_RESULTCODE) { if (resultCode == Activity.RESULT_OK && intent