在android中按下菜单按钮时如何显示按钮

嗨，朋友们，当按下安卓键盘上的默认菜单按钮时，我想从屏幕底部弹出一个按钮。我想从弹出按钮导航到其他屏幕

首先必须在/menu/menu.xml中声明所需的菜单 然后，您的菜单需要一个充气机：

// menuinflater 
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.menu, menu);
    return true;
}

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        // only one menu option here for preferences
        // for more just add new case with your ids
        case R.id.firstmenuitem:
            // Launch preferences activity
            Intent i = new Intent(youractivity.this, preferences.class);
            startActivity(i);
            break;

        }
        return true;
    }       

要处理菜单，请执行以下操作：

// menuinflater 
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.menu, menu);
    return true;
}

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        // only one menu option here for preferences
        // for more just add new case with your ids
        case R.id.firstmenuitem:
            // Launch preferences activity
            Intent i = new Intent(youractivity.this, preferences.class);
            startActivity(i);
            break;

        }
        return true;
    }       

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关于

您首先必须在/menu/menu.xml中声明所需的菜单 然后，您的菜单需要一个充气机：

// menuinflater 
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.menu, menu);
    return true;
}

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        // only one menu option here for preferences
        // for more just add new case with your ids
        case R.id.firstmenuitem:
            // Launch preferences activity
            Intent i = new Intent(youractivity.this, preferences.class);
            startActivity(i);
            break;

        }
        return true;
    }       

要处理菜单，请执行以下操作：

// menuinflater 
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.menu, menu);
    return true;
}

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        // only one menu option here for preferences
        // for more just add new case with your ids
        case R.id.firstmenuitem:
            // Launch preferences activity
            Intent i = new Intent(youractivity.this, preferences.class);
            startActivity(i);
            break;

        }
        return true;
    }       

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另一种方法是使用onKeyDown事件，另一种方法是使用onKeyDown事件