Android WebView文件上传选项无法使用，请求技术修复

WebView默认不处理文件上传的Intent请求，需要补充以下逻辑解决问题：

1. 核心修改点 #

• 自定义WebChromeClient实现文件选择回调
• 处理文件选择后的结果返回
• 配置必要的权限

修改后的完整代码 #

public class MainActivity extends AppCompatActivity {
    private static final int FILE_CHOOSER_REQUEST_CODE = 100;
    private ValueCallback<Uri[]> mFilePathCallback;
    ActivityMainBinding binding;
    WebView mWebView;
    public String url = "https://google.com/";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = ActivityMainBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());

        Log.d("MainActivity", "Main Activity Open");

        mWebView = binding.myWebView;
        ProgressDialog progress = new ProgressDialog(this);
        progress.setTitle("Loading");
        progress.setMessage("Wait while loading...");
        progress.setCancelable(false);
        progress.show();

        WebSettings webSettings = mWebView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        webSettings.setLoadWithOverviewMode(true);
        webSettings.setUseWideViewPort(true);
        webSettings.setBuiltInZoomControls(true);
        webSettings.setPluginState(WebSettings.PluginState.ON);
        // 启用文件访问权限
        webSettings.setAllowFileAccess(true);
        webSettings.setAllowContentAccess(true);

        mWebView.setWebViewClient(new WebViewClient());
        // 设置自定义WebChromeClient处理文件上传请求
        mWebView.setWebChromeClient(new WebChromeClient() {
            @Override
            public boolean onShowFileChooser(WebView webView, ValueCallback<Uri[]> filePathCallback, FileChooserParams fileChooserParams) {
                // 释放旧的回调避免内存泄漏
                if (mFilePathCallback != null) {
                    mFilePathCallback.onReceiveValue(null);
                }
                mFilePathCallback = filePathCallback;

                // 启动系统文件选择器
                Intent intent = fileChooserParams.createIntent();
                try {
                    startActivityForResult(intent, FILE_CHOOSER_REQUEST_CODE);
                } catch (ActivityNotFoundException e) {
                    mFilePathCallback = null;
                    Toast.makeText(MainActivity.this, "无法打开文件选择器", Toast.LENGTH_SHORT).show();
                    return false;
                }
                return true;
            }
        });

        if (!DetectConnection.checkInternetConnection(this)) {
            mWebView.loadUrl("file:///android_asset/error.html");
        } else {
            mWebView.loadUrl(url);
        }

        progress.dismiss();
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode != FILE_CHOOSER_REQUEST_CODE) {
            return;
        }

        Uri[] results = null;
        // 处理选择的文件结果
        if (resultCode == Activity.RESULT_OK && data != null) {
            ClipData clipData = data.getClipData();
            String dataString = data.getDataString();

            if (clipData != null) {
                results = new Uri[clipData.getItemCount()];
                for (int i = 0; i < clipData.getItemCount(); i++) {
                    results[i] = clipData.getItemAt(i).getUri();
                }
            } else if (dataString != null) {
                results = new Uri[]{Uri.parse(dataString)};
            }
        }

        // 将结果返回给WebView
        if (mFilePathCallback != null) {
            mFilePathCallback.onReceiveValue(results);
            mFilePathCallback = null;
        }
    }

    // 处理权限申请结果
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (grantResults.length > 0 && grantResults[0] != PackageManager.PERMISSION_GRANTED) {
            Toast.makeText(this, "需要存储权限才能上传文件", Toast.LENGTH_SHORT).show();
        }
    }
}

权限配置（AndroidManifest.xml） #

在清单文件中添加对应权限：

<!-- Android 12及以下版本 -->
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<!-- Android 13及以上版本 -->
<uses-permission android:name="android.permission.READ_MEDIA_IMAGES" />
<uses-permission android:name="android.permission.READ_MEDIA_VIDEO" />

额外说明 #

• 若使用AndroidX，建议用registerForActivityResult替代已废弃的onActivityResult
• 测试前确认网页的上传表单本身功能正常，排除网页端问题

内容的提问来源于stack exchange，提问作者Andy Jadeja