java - 微调器显示黑色

Question

我对旋转器设计有疑问。我正在使用此代码生成下拉微调器:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_my);

    LinearLayout layout = new LinearLayout(this);

    ArrayList < String > spinnerArray = new ArrayList < String > ();
    spinnerArray.add("one");
    spinnerArray.add("two");
    spinnerArray.add("three");
    spinnerArray.add("four");
    spinnerArray.add("five");

    Spinner spinner = new Spinner(this);
    ArrayAdapter < String > spinnerArrayAdapter = new ArrayAdapter < String > (this,
        android.R.layout.simple_spinner_dropdown_item, spinnerArray);
    spinner.setAdapter(spinnerArrayAdapter);

    layout.addView(spinner);

    setContentView(layout);
}

它显示:

如何去除阻挡旋转器的黑色？

Answer 1

layout.addView(spinner);
setContentView(layout);

当您将 View 动态添加到布局时。你缺少一些配置。这就是您看到黑匣子的原因。

尝试下面的代码:

xml:

<Spinner
    android:id="@+id/planets_spinner"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" />

Activity :

Spinner spinner = (Spinner) findViewById(R.id.spinner);
    // Create an ArrayAdapter using the string array and a default spinner layout
    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
            arraydata, android.R.layout.simple_spinner_item);
    // Specify the layout to use when the list of choices appears
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    // Apply the adapter to the spinner
    spinner.setAdapter(adapter);