protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); ipEditText = findViewById(R.id.ipEditText); portEditText = findViewById(R.id.portEditText); Button connectButton = findViewById(R.id.connectButton); connectButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { String ip = ipEditText.getText().toString(); int port = Integer.parseInt(portEditText.getText().toString()); new Thread(new Runnable() { @Override public void run() { try { socket = new Socket(ip, port); in = new BufferedReader(new InputStreamReader(socket.getInputStream())); out = new PrintWriter(socket.getOutputStream(), true); // 获取SeekBar对象 SeekBar progressBar = findViewById(R.id.progressBar); // 添加OnSeekBarChangeListener监听器 progressBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() { @Override public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) { // 计算百分比对应的数字 int number = progress * 10; out.println(number); } @Override public void onStartTrackingTouch(SeekBar seekBar) { } @Override public void onStopTrackingTouch(SeekBar seekBar) { } }); } catch (UnknownHostException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } }).start(); } }); Button sendMessageButton = findViewById(R.id.sendMessageButton); sendMessageButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { showSendMessageDialog(); } }); }主线程有问题，能帮我修改一下吗

可能是因为您没有在UI线程上更新UI。建议使用runOnUiThread方法将UI更新放在UI线程上。

以下是修改后的代码：

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

    ipEditText = findViewById(R.id.ipEditText);
    portEditText = findViewById(R.id.portEditText);

    Button connectButton = findViewById(R.id.connectButton);
    connectButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String ip = ipEditText.getText().toString();
            int port = Integer.parseInt(portEditText.getText().toString());
            new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        socket = new Socket(ip, port);
                        in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                        out = new PrintWriter(socket.getOutputStream(), true);

                        // 获取SeekBar对象
                        SeekBar progressBar = findViewById(R.id.progressBar);

                        // 添加OnSeekBarChangeListener监听器
                        progressBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
                            @Override
                            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                                // 计算百分比对应的数字
                                int number = progress * 10;
                                out.println(number);
                            }

                            @Override
                            public void onStartTrackingTouch(SeekBar seekBar) {
                            }

                            @Override
                            public void onStopTrackingTouch(SeekBar seekBar) {
                            }
                        });
                    } catch (UnknownHostException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }).start();
        }
    });

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

// 在UI线程上更新UI
private void updateUI(Runnable runnable) {
    runOnUiThread(runnable);
}

private void showSendMessageDialog() {
    // 创建AlertDialog.Builder对象
    AlertDialog.Builder builder = new AlertDialog.Builder(this);

    // 设置标题和消息
    builder.setTitle("Send Message");
    builder.setMessage("Please enter the message:");

    // 添加一个EditText
    final EditText input = new EditText(this);
    builder.setView(input);

    // 添加确定按钮
    builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            // 获取用户输入的文本
            String message = input.getText().toString();

            // 发送消息到服务器
            out.println(message);

            // 在UI线程上更新UI
            updateUI(new Runnable() {
                @Override
                public void run() {
                    // 显示Toast提示消息发送成功
                    Toast.makeText(MainActivity.this, "Message sent successfully", Toast.LENGTH_SHORT).show();
                }
            });
        }
    });

    // 添加取消按钮
    builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            dialog.cancel();
        }
    });

    // 显示对话框
    AlertDialog dialog = builder.create();
    dialog.show();
}

在这个修改后的代码中，我们添加了一个 `updateUI` 方法，用于在UI线程上更新UI。在 `showSendMessageDialog` 方法中，我们使用 `updateUI` 方法来显示Toast提示消息发送成功。