Question

我是Android开发编程的新手。我正试图将我的开始活动中的多个信息传递给新活动，我无法弄清楚如何检索所有值。

我的MainActivity buttonSend事件代码是：

public void sendInformation (View view) {

    Intent intent = new Intent(this, DisplayInformation.class);
    EditText toText = (EditText) findViewById (R.id.toText);                //Finds the control 'toText' in the form and gets it by ID
    EditText fromText = (EditText) findViewById (R.id.fromText);            //Finds the control 'fromText' in the form and gets it by ID
    EditText messageText = (EditText) findViewById (R.id.messageText);      //Finds the control 'messageText' in the form and gets it by ID
    EditText subjectText = (EditText) findViewById (R.id.subjectText);      //Finds the control 'subjectText' in the form and gets it by ID

    String toMessage = toText.getText().toString();                         //Gets the text that you enter for the 'To'Field
    String fromMessage = fromText.getText().toString();                     //Gets the text that you enter for the 'From' field
    String messageMessage = messageText.getText().toString();               //Gets the text that you enter for the 'Message' field
    String subjectMessage = subjectText.getText().toString();               //Gets the text that you enter for the 'Subject' field

    intent.putExtra(EXTRA_MESSAGE, toMessage);
    intent.putExtra(EXTRA_MESSAGE, fromMessage);
    intent.putExtra(EXTRA_MESSAGE, messageMessage);
    intent.putExtra(EXTRA_MESSAGE, subjectMessage);

    startActivity(intent);
}

EXTRA_MESSAGE被定义为public final static String EXTRA_MESSAGE = "com.example.Fun.MESSAGE";我真的不知道这是什么，说实话，教程只是告诉我要包含它。

在我的第二个活动页面中，我有onCreate实例的代码：

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

    if (savedInstanceState == null) {
        getSupportFragmentManager().beginTransaction()
                .add(R.id.container, new PlaceholderFragment()).commit();
    }

    Intent intent = getIntent();
    String toMessage = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
    String fromMessage = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
    String subjectMessage = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
    String messageMessage = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);

    TextView toMessagetextView = new TextView(this);
    toMessagetextView.setTextSize(40);
    toMessagetextView.setText(toMessage);

    TextView fromMessagetextView = new TextView(this);
    fromMessagetextView.setTextSize(40);
    fromMessagetextView.setText(fromMessage);

    TextView subjectMessagetextView = new TextView(this);
    subjectMessagetextView.setTextSize(40);
    subjectMessagetextView.setText(subjectMessage);

    TextView messageMessagetextView = new TextView(this);
    messageMessagetextView.setTextSize(40);
    messageMessagetextView.setText(messageMessage);



    setContentView(toMessagetextView);
    setContentView(fromMessagetextView);
    setContentView(subjectMessagetextView);
    setContentView(messageMessagetextView);



}

当我去运行我的应用程序时，它会出错并关闭。

*如果有人可以告诉我如何将TextView放在fragment.xml文件中进行第二次活动，我们将不胜感激。我知道如何声明id以及我不知道如何使用它来检索来自其他活动的数据。

提前感谢您的帮助。

Answer 1

您对所有额外值使用相同的键EXTRA_MESSAGE。 Intent存储像Map这样的值。

所以你在这里除了subjectMessage以外的所有其他价值，因为它最后被添加了。

您必须为每个值使用不同的键。喜欢

public final static String EXTRA_MESSAGE_TO = "com.example.Fun.MESSAGE_TO";
public final static String EXTRA_MESSAGE_FROM = "com.example.Fun.MESSAGE_FROM";
public final static String EXTRA_MESSAGE_SUBJECT = "com.example.Fun.MESSAGE_SUBJECT";
public final static String EXTRA_MESSAGE = "com.example.Fun.MESSAGE";

检索新活动的多个信息

1 个答案: