android 查询本地视频文件

查询本地视频文件流程

流程图

flowchart TD

A[开始] --> B[获取读取权限]
B --> C[检查SD卡是否可用]
C --> D[查询本地视频文件]
D --> E[显示视频列表]
E --> F[结束]

类图

classDiagram
    class MainActivity{
        - File videoFolder
        - ArrayList<String> videoList
        - ListView listView
        - ArrayAdapter<String> adapter
        + onCreate(Bundle savedInstanceState)
        - getPermission()
        - checkSDCard()
        - queryVideoFiles()
        - displayVideoList()
    }

详细步骤

1. 获取读取权限

在AndroidManifest.xml文件中添加如下权限：

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

2. 检查SD卡是否可用

在MainActivity类的checkSDCard方法中，使用以下代码进行检查：

String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
    // SD卡可用
} else {
    // SD卡不可用
}

3. 查询本地视频文件

在MainActivity类的queryVideoFiles方法中，使用以下代码查询本地视频文件：

videoFolder = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MOVIES);
File[] videoFiles = videoFolder.listFiles(new FileFilter() {
    @Override
    public boolean accept(File file) {
        return file.isFile() && file.getName().endsWith(".mp4");
    }
});
videoList = new ArrayList<>();
for (File videoFile : videoFiles) {
    videoList.add(videoFile.getName());
}

4. 显示视频列表

在MainActivity类的displayVideoList方法中，使用以下代码显示视频列表：

listView = findViewById(R.id.list_view);
adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, videoList);
listView.setAdapter(adapter);

完整代码示例：

public class MainActivity extends AppCompatActivity {
    private File videoFolder;
    private ArrayList<String> videoList;
    private ListView listView;
    private ArrayAdapter<String> adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        getPermission();
        checkSDCard();
        queryVideoFiles();
        displayVideoList();
    }

    private void getPermission() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
                requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 1);
            }
        }
    }

    private void checkSDCard() {
        String state = Environment.getExternalStorageState();
        if (Environment.MEDIA_MOUNTED.equals(state)) {
            // SD卡可用
        } else {
            // SD卡不可用
        }
    }

    private void queryVideoFiles() {
        videoFolder = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MOVIES);
        File[] videoFiles = videoFolder.listFiles(new FileFilter() {
            @Override
            public boolean accept(File file) {
                return file.isFile() && file.getName().endsWith(".mp4");
            }
        });
        videoList = new ArrayList<>();
        for (File videoFile : videoFiles) {
            videoList.add(videoFile.getName());
        }
    }

    private void displayVideoList() {
        listView = findViewById(R.id.list_view);
        adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, videoList);
        listView.setAdapter(adapter);
    }
}

希望对你有所帮助！