MyFirstApp 教程 Android Studio 在应用程序内接收消息时出现问题。
构建错误如下:
Error:(17, 60) error: cannot find symbol variable EXTRA_MESSAGE
Error:(20, 57) error: cannot find symbol variable textView
我的消息接收器代码如下所示:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_display_message);
// Get the Intent that started this activity and extract the
string
Intent intent = getIntent();
String message =
intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
// Capture the layout's TextView and set the string as its text
TextView textView = (TextView) findViewById(R.id.textView);
textView.setText(message);
}
注意:EXTRA_MESSAGE 和 textview 为红色。
发送代码如下所示:
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
/** Called when the user taps the Send button */
public void sendMessage(View view) {
Intent intent = new Intent(this,
DisplayMessageActivity.class);
EditText editText = (EditText) findViewById(R.id.editText);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
}
注意:在我上面的代码中的这一行:
public void sendMessage(View view)
第一个“View”有一条浅水平线穿过它,我收到一条错误消息,例如 sendMessage(View view) is depreciated。
我认为问题可能与
public void sendMessage(View view)
及其折旧代码消息...(?)
出现问题的教程的链接:
https://developer.android.com/training/basics/firstapp/starting-activity.html
最佳答案
检查您的 MainActivity.java 文件中的这一行,您的代码中是否缺少。
public static final String EXTRA_MESSAGE = "com.example.myfirstapp.MESSAGE";
关于java - MyFirstApp 教程 Android Studio 2.3 Build Errors re EXTRA_MESSAGE 和 textview,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/44981541/