TextView setText() 在错误上下文的回调中调用

Question

我尝试实现网络服务发现并在成功注册后将名称设置到 textView 中。但是我收到 android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views. 异常。我的基本结构如下所示：

NsdManager.RegistrationListener mRegistrationListener;

onCreate() {
    mRegistrationListener = new NsdManager.RegistrationListener() {
        onServiceRegistered(serviceInfo) {
            TextView textView = (TextView) findViewById(R.id.nsdServiceNameText);
            textView.setText(serviceInfo.getServiceName());
        }
    }
    
    mNsdManager = (NsdManager) this.getBaseContext().getSystemService(Context.NSD_SERVICE);

    mNsdManager.registerService(
        serviceInfo,
        NsdManager.PROTOCOL_DNS_SD,
        mRegistrationListener);
}

对我来说，我可能在错误的上下文中编辑视图是有道理的，但我是如何到达那里的，更重要的是我如何解决这个问题？

Answer 1

如果您在此处阅读 NsdManager 的文档：https://developer.android.com/reference/android/net/nsd/NsdManager

上面写着：

The API is asynchronous, and responses to requests from an application are on listener callbacks on a separate internal thread.

因此它离开了 UI 线程，您应该在该线程中更新您的 UI，正如评论中指出的，如下所示：

runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    textView.setText(serviceInfo.getServiceName());
                }
            });

TextView setText() 在错误上下文的回调中调用

TextView setText() called in callbacks from wrong context

java

android

callback

textview