java - 第二次用字符串元素数组填充微调器时出错

Question

我有一个微调器，可以让我选择特定的文本。我正在以编程方式创建第二个微调器，并在其中放置不同的字符串元素数组，具体取决于从第一个微调器中选择某些内容时激活的开关中所做的选择。第二个微调器位于 LinearLayout 内。当我第一次从第一个微调器中选择一个选项时，一切正常，当我选择另一个选项时，一切都崩溃了。你能帮我检测是什么导致了这种情况发生吗？

    final String[] as = {"AB", "AC", "AD", "AE", "AF", "AG","AH"};
    final String[] bs = {"BC", "BD", "BE", "BF", "BG", "BH", "BI"};

在 onCreate 方法中

    //second Spinner
    second_layout = findViewById(R.id.second_spinner);
    spinner_2 = new Spinner(this);

开关

    @Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
    String comb_selected = String.valueOf(spinner_1.getSelectedItem());

    switch (comb_selected){
        case "As"                
            second_layout.setVisibility(View.VISIBLE);
            fillSecondSpinner(as);
            break;
        case "Bs":                
            second_layout.setVisibility(View.VISIBLE);
            fillSecondSpinner(bs);
            break;
        default:
            flag.setVisibility(View.INVISIBLE);
            second_layout.setVisibility(View.INVISIBLE);
            break;

让一切崩溃的函数

    public void fillSecondSpinner(String[] combinations){
    ArrayAdapter<CharSequence> adapter_comb = new ArrayAdapter(this, android.R.layout.simple_spinner_item, combinations);
    adapter_comb.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinner_2.setAdapter(adapter_villes);
    second_layout.addView(spinner_2);
}

这是我得到的错误:

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.exercice1.spinner2, PID: 2304
    java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
        at android.view.ViewGroup.addViewInner(ViewGroup.java:4417)
        at android.view.ViewGroup.addView(ViewGroup.java:4258)
        at android.view.ViewGroup.addView(ViewGroup.java:4198)
        at android.view.ViewGroup.addView(ViewGroup.java:4171)
        at com.exercice1.spinner2.MainActivity.fillSecondSpinner(MainActivity.java:49)
        at com.exercice1.spinner2.MainActivity.onItemSelected(MainActivity.java:68)
        at android.widget.AdapterView.fireOnSelected(AdapterView.java:931)
        at android.widget.AdapterView.dispatchOnItemSelected(AdapterView.java:920)
        at android.widget.AdapterView.-wrap1(AdapterView.java)
        at android.widget.AdapterView$SelectionNotifier.run(AdapterView.java:890)
        at android.os.Handler.handleCallback(Handler.java:751)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6119)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
Application terminated.

Answer 1

好吧，您需要先删除旧 View ，然后再创建新 View 。 在添加之前尝试调用此方法:

second_layout.removeAllViews()