provider标签内容提供器

「爱情、让人受尽委屈。」 2022-09-26 03:15 161阅读 0赞

只要不懂就会入坑，就算是看起来理所当然，也是一样的。

首先是res/xml文件夹下的.xml文件

测试好多遍了，最后发现是这么回事，

getFilesDir()  *data/data/com.example.li.myfileprovider/files*

content uri   uri=*content://com.example.li.myfileprovider.fileprovider/myimages/file.txt*

<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.li.myfileprovider">
    
        <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
        <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
        <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:supportsRtl="true" android:theme="@style/AppTheme">
            <activity android:name=".MainActivity" android:label="@string/app_name" android:theme="@style/AppTheme.NoActionBar">
                <intent-filter>
                    <action android:name="android.intent.action.MAIN" />
    
                    <category android:name="android.intent.category.LAUNCHER" />
                </intent-filter>
            </activity>
            <activity android:name=".FileSelectActivity" android:label="File Selector">
                <intent-filter>
                    <action android:name="android.intent.action.PICK"/>
                    <category android:name="android.intent.category.DEFAULT"/>
                    <category android:name="android.intent.category.OPENABLE" />
    
                    <data android:mimeType="text/plain" />
                    <data android:mimeType="image/*" />
                </intent-filter>
    
            </activity>
            <provider android:authorities="com.example.li.myfileprovider.fileprovider" android:name="android.support.v4.content.FileProvider" android:exported="false" android:grantUriPermissions="true">
                <meta-data android:name="android.support.FILE_PROVIDER_PATHS" android:resource="@xml/filepaths">
    
                </meta-data>
            </provider>
        </application>
    
    </manifest> 文件选择Activity public class FileSelectActivity extends Activity {
    
    
        private File mImageDir;
        private List<File> mImageFiles;
        private String[] mImageFileName;
        private Intent mResultIntent;
        private ListView listView;
        private ArrayAdapter<String> adapter;
        private Button button;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
          /* */ super.onCreate(savedInstanceState);
            setContentView(R.layout.list_view);
            button = (Button) findViewById(R.id.ok);
    
            mResultIntent=new Intent("com.example.li.myfileprovider.ACTION_RETURN_FILE");
            listView = (ListView) findViewById(R.id.list_view);
            List<String> data=getStrings();
            if (data!=null) {
                adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, data);
                listView.setAdapter(adapter);
    
            }
            clickListView();
            setResult(Activity.RESULT_CANCELED,    null);
        }
        private List<String> getStrings(){
            List<String> list = new ArrayList<>();
            mImageFiles = new ArrayList<>();
            ///data/data/com.example.li.myfileprovider/files getFilesDir(); File dir = new File(getFilesDir(), "files");
    
            if (dir.exists()) {
                File []listFiles=dir.listFiles();
                for (File file : listFiles) {
                    mImageFiles.add(file);
                    String name=file.getName();
                    list.add(name);
    
                }
                Log.d("test", "dir success");
                return list;
            }else {
                Log.d("test", "dir failed");
                return null;
            }
    
    
        }
        public void clickListView(){
            listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                @Override
                public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                    File selectedFile = mImageFiles.get(i);
                    Log.d("test", selectedFile.getAbsolutePath());
    /* getFilesDir()  data/data/com.example.li.myfileprovider/files Uri uri = Uri.parse("content://com.example.li.myfileprovider.fileprovider/myimages/" + selectedFile.getName() );*/ //content://com.example.li.myfileprovider.fileprovider/myimages/files3.txt uri Uri uri = FileProvider.getUriForFile(FileSelectActivity.this, "com.example.li.myfileprovider.fileprovider", selectedFile);                Log.d("test", uri.toString() + " uri");                if (uri != null) {                    mResultIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);//零时可读，退出关闭                    mResultIntent.setDataAndType(uri, getContentResolver().getType(uri));                    FileSelectActivity.this.setResult(Activity.RESULT_OK,mResultIntent);                }else {                    mResultIntent.setDataAndType(null, "");                    FileSelectActivity.this.setResult(Activity.RESULT_CANCELED,mResultIntent);                }                ///data/data/com.example.li.myfileprovider/files/images/images3.txt }        });    }    public void onClick(View view) {        finish();    }} 
     GetFileDemo Cursor cursor = getContentResolver().query(returnUri, null, null, null, null);
    /*String fileName = cursor.getString(cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME)); long fileSize = cursor.getLong(cursor.getColumnIndex(OpenableColumns.SIZE));*/ cursor.moveToFirst();//查询的结果curson要移到第一行 int namecolumn = cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME);
    int sizecolumn = cursor.getColumnIndex(OpenableColumns.SIZE);
    Log.d("test", cursor.getPosition()+"first");
    /*cursor.moveToFirst();*///确保在第一行 String fileName = cursor.getString(namecolumn);
    long fileSize = cursor.getLong(sizecolumn);
    Log.d("test", cursor.getPosition() + "second");
    name.setText("name"+fileName);
    /*cursor.moveToFirst()*/ cursor.close();