Question

我正试图在Android工作室中为我的应用设置操作栏。我一直在关注Google教程，但出于某种原因，我在运行应用时没有显示我放在栏上的项目。但它们确实出现在设计窗口中。

这是从Google教程中复制的XML

<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">

<!-- "Mark Favorite", should appear as action button if possible -->
<item
    android:id="@+id/action_favorite"
    android:icon="@drawable/ic_favorite_black_48dp"
    android:title="@string/action_favorite"
    app:showAsAction="ifRoom"/>

<!-- Settings, should always be in the overflow -->
<item
    android:id="@+id/action_settings"
    android:title="@string/action_settings"
    app:showAsAction="never"/>

</menu>

这里是主要活动的完整代码，我在其底部尝试使用操作栏项。

package php.comget_all.ipeelu.httpweb_service_test.intenseapp;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.ScrollView;
import android.widget.TableLayout;
import android.widget.TableRow;
import android.widget.TextView;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Stack;

public class MainActivity extends AppCompatActivity {

private Button sendButton;
public EditText editText;
public Stack<TableRow> messageStack;
public LinearLayout messagesDisplayLayout;
public ScrollView scroller;
private TextView response;
private EditText editTextAddress, editTextPort;
private Button buttonConnect, buttonClear;

private Client client;

// Boolean telling us whether a download is in progress, so we don't trigger overlapping
// downloads with consecutive button clicks.
private boolean mDownloading = false;


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

    Toolbar myToolbar = (Toolbar) findViewById(R.id.my_toolbar);
    setSupportActionBar(myToolbar);

    client = new Client("10.0.2.2", 12345, this);
    client.execute();

    messagesDisplayLayout = (TableLayout) findViewById(R.id.messageDisplay);
    sendButton = (Button) findViewById(R.id.sendButton);
    editText = (EditText) findViewById(R.id.edit_message);
    scroller = (ScrollView) findViewById(R.id.scroller);
    editText.addTextChangedListener(new TextWatcher() {

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            if(s.length() != 0)
                sendButton.setEnabled(true);
            else
                sendButton.setEnabled(false);
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {}

        @Override
        public void afterTextChanged(Editable s) {}
    });
    messageStack = new Stack<TableRow>();
}

/** Called when the user clicks the Send button */
public void sendMessage(View view)
{
    SimpleDateFormat simpleDateFormat = new SimpleDateFormat("hh:mm");
    String ts = simpleDateFormat.format(new Date());
    String message = editText.getText().toString();
    TextView messageTV = new TextView(this);
    messageTV.setText(ts + ": " + message);
    messageTV.setTextSize(20);
    TableRow messageRow = new TableRow(this);
    messageRow.setPadding(0,20,0,0);
    messageRow.addView(messageTV);
    messageTV.getLayoutParams().width = LinearLayout.LayoutParams.WRAP_CONTENT;
    messageTV.getLayoutParams().height = LinearLayout.LayoutParams.WRAP_CONTENT;
    messagesDisplayLayout.addView(messageRow);
    messageStack.push(messageRow);
    editText.getText().clear();
    scroller.fullScroll(scroller.FOCUS_DOWN);

    //client.sendMessage(message);
    synchronized (client.thingy)
    {
        client.message = message;
        client.thingy.notify();
    }
}

public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case R.id.action_settings:
            // User chose the "Settings" item, show the app settings UI...
            return true;

        case R.id.action_favorite:
            // User chose the "Favorite" action, mark the current item
            // as a favorite...
            return true;

        default:
            // If we got here, the user's action was not recognized.
            // Invoke the superclass to handle it.
            return super.onOptionsItemSelected(item);

    }
}
}

对不起，如果我犯了任何新手的错误，我可能会像Android Studio一样陌生。不过我已经看了这个，并且无法在任何地方找到合适的答案，所以这是我最后的选择。

Answer 1

您永远不会夸大菜单，您需要覆盖onCreateOptionsMenu

实施例

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.my_menu, menu);
    return true;
}

Android Studio：操作栏图标显示在设计窗口中，但在运行应用

1 个答案: