Android实现读取SD卡下所有TXT文件名并用listView显示出来的方法

下面是实现读取SD卡下所有TXT文件名并用listView显示出来的方法的攻略：

1. 确认权限

首先我们需要在AndroidManifest.xml中添加读取SD卡权限：

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

1. 获取SD卡目录

获取SD卡的根目录路径：

String sdCardPath = Environment.getExternalStorageDirectory().getAbsolutePath();

1. 遍历TXT文件

遍历SD卡下所有的TXT文件，获取文件名并添加到List中：

File sdCardFolder = new File(sdCardPath);
List<String> txtFileList = new ArrayList<>();
if (sdCardFolder.exists() && sdCardFolder.isDirectory()) {
    File[] files = sdCardFolder.listFiles();
    for (File file : files) {
        if (file.isFile() && file.getName().endsWith(".txt")) {
            txtFileList.add(file.getName());
        }
    }
}

1. 绑定ListView

将txtFileList绑定到ListView上：

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

下面是完整的代码示例：

public class MainActivity extends AppCompatActivity {

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

        String sdCardPath = Environment.getExternalStorageDirectory().getAbsolutePath();
        File sdCardFolder = new File(sdCardPath);
        List<String> txtFileList = new ArrayList<>();
        if (sdCardFolder.exists() && sdCardFolder.isDirectory()) {
            File[] files = sdCardFolder.listFiles();
            for (File file : files) {
                if (file.isFile() && file.getName().endsWith(".txt")) {
                    txtFileList.add(file.getName());
                }
            }
        }

        ListView listView = findViewById(R.id.listView);
        ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, txtFileList);
        listView.setAdapter(adapter);
    }
}

另外，可以参考以下两个示例：

1. 按钮触发读取：

public class MainActivity extends AppCompatActivity {

    private List<String> txtFileList = new ArrayList<>();
    private ArrayAdapter<String> adapter;

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

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

        Button button = findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                readTxtFile();
            }
        });
    }

    private void readTxtFile() {
        String sdCardPath = Environment.getExternalStorageDirectory().getAbsolutePath();
        File sdCardFolder = new File(sdCardPath);
        if (sdCardFolder.exists() && sdCardFolder.isDirectory()) {
            File[] files = sdCardFolder.listFiles();
            txtFileList.clear();
            for (File file : files) {
                if (file.isFile() && file.getName().endsWith(".txt")) {
                    txtFileList.add(file.getName());
                }
            }
            adapter.notifyDataSetChanged();
        }
    }
}

1. 添加文件长按事件：

public class MainActivity extends AppCompatActivity {

    private List<String> txtFileList = new ArrayList<>();
    private ArrayAdapter<String> adapter;

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

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

        listView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
            @Override
            public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
                String fileName = txtFileList.get(position);
                deleteFileDialog(fileName);
                return true;
            }
        });

        readTxtFile();
    }

    private void readTxtFile() {
        String sdCardPath = Environment.getExternalStorageDirectory().getAbsolutePath();
        File sdCardFolder = new File(sdCardPath);
        if (sdCardFolder.exists() && sdCardFolder.isDirectory()) {
            File[] files = sdCardFolder.listFiles();
            txtFileList.clear();
            for (File file : files) {
                if (file.isFile() && file.getName().endsWith(".txt")) {
                    txtFileList.add(file.getName());
                }
            }
            adapter.notifyDataSetChanged();
        }
    }

    private void deleteFileDialog(final String fileName) {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("删除文件");
        builder.setMessage("是否删除：" + fileName);
        builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                String sdCardPath = Environment.getExternalStorageDirectory().getAbsolutePath();
                File file = new File(sdCardPath, fileName);
                if (file.exists()) {
                    file.delete();
                    readTxtFile();
                }
            }
        });
        builder.setNegativeButton("取消", null);
        builder.show();
    }
}

希望能够对你有帮助。