文件上传的逻辑

app/src/main/java/com/pxkj/jwzs/FirstActivity.java

@@ -24,6 +24,11 @@ import android.widget.Toast;
 import androidx.annotation.Nullable;
 import androidx.annotation.RequiresApi;
 
+import android.app.Activity;
+import android.content.Intent;          // ← 文件选择核心类
+import android.database.Cursor;        // ← 解析文件信息
+import android.provider.OpenableColumns; // ← 获取文件名、大小
+
 import java.io.IOException;
 import java.io.InputStream;
 import java.lang.ref.WeakReference;
@@ -275,6 +280,7 @@ public class FirstActivity extends BaseActivity {
 
             DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
             if (dm != null) {
+                Toast.makeText(this, "文件已开始下载，请等待", Toast.LENGTH_SHORT).show();
                 currentDownloadId = dm.enqueue(request);
                 startDownloadProgressMonitor(dm, currentDownloadId);
             } else {
@@ -298,7 +304,6 @@ public class FirstActivity extends BaseActivity {
 
         while (downloading) {
             try {
-                Toast.makeText(this, "文件已开始下载，请等待", Toast.LENGTH_SHORT).show();
                 Thread.sleep(1000);
                 android.database.Cursor cursor = dm.query(query);
                 if (cursor != null && cursor.moveToFirst()) {
@@ -337,6 +342,71 @@ public class FirstActivity extends BaseActivity {
         }
     }
 
+    // 在 FirstActivity.java 中添加以下代码
+
+    private static final int REQUEST_CODE_FILE_PICK = 2001;
+    private Uri selectedFileUri;
+
+    private void chooseFile() {
+        runOnUiThread(() -> {
+            Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
+            intent.setType("*/*"); // 所有类型
+            intent.addCategory(Intent.CATEGORY_OPENABLE);
+            startActivityForResult(Intent.createChooser(intent, "请选择文件"), REQUEST_CODE_FILE_PICK);
+        });
+    }
+
+    /**
+     * 选择文件后的回调
+     */
+    @Override
+    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
+        super.onActivityResult(requestCode, resultCode, data);
+        if (requestCode == REQUEST_CODE_FILE_PICK && resultCode == RESULT_OK && data != null) {
+            selectedFileUri = data.getData();
+            if (selectedFileUri != null) {
+                String fileName = getFileNameFromUri(selectedFileUri);
+                String filePath = selectedFileUri.toString();
+
+                // 将选择的文件信息传回前端 JS
+                if (webView != null) {
+                    String jsCode = String.format(
+                            "if(window.onFileChosen){window.onFileChosen('%s','%s');}",
+                            fileName.replace("'", "\\'"),
+                            filePath.replace("'", "\\'")
+                    );
+                    webView.evaluateJavascript(jsCode, null);
+                }
+
+                Toast.makeText(this, "已选择文件: " + fileName, Toast.LENGTH_SHORT).show();
+            }
+        }
+    }
+
+    /**
+     * 从 Uri 中获取文件名
+     */
+    private String getFileNameFromUri(Uri uri) {
+        String result = null;
+        if ("content".equals(uri.getScheme())) {
+            try (android.database.Cursor cursor = getContentResolver().query(uri, null, null, null, null)) {
+                if (cursor != null && cursor.moveToFirst()) {
+                    result = cursor.getString(cursor.getColumnIndex(android.provider.OpenableColumns.DISPLAY_NAME));
+                }
+            }
+        }
+        if (result == null) {
+            result = uri.getPath();
+            int cut = result.lastIndexOf('/');
+            if (cut != -1) {
+                result = result.substring(cut + 1);
+            }
+        }
+        return result;
+    }
+
+
+
     public static class JsBridge {
         private final WeakReference<FirstActivity> activityRef;
 
@@ -369,6 +439,14 @@ public class FirstActivity extends BaseActivity {
                 activity.runOnUiThread(() -> activity.downloadFile(url));
             }
         }
+        // ✅ 供前端调用的文件选择方法
+        @JavascriptInterface
+        public void chooseFile() {
+            FirstActivity activity = activityRef.get();
+            if (activity != null) {
+                activity.runOnUiThread(activity::chooseFile);
+            }
+        }
 
         @JavascriptInterface
         public void showLog(String message) {