radioGroup如何隐藏按钮android

Question

Hello I want to create a list. On long-press on the toolbar will be shown option to select all and delete selected. I don't know whether I should RadioGroup and hide button or use listView and create own row example and there add radio button.

Answer 1

Where I cant get very specific, I can say, usually to achieve your own specific goals creating your own row will prove beneficial to your end goal. Rather then hiding a RadioGroup

Answer 2

Default standard android behavior is Contextual Action Bar(which I can interpret) should come when user long presses an item list as in

One of the many resources are

http://theopentutorials.com/examples/android/listview/android-contextual-action-bar-for-listview-item-deletion-using-actionbarsherlock/

https://androidkennel.org/contextual-toolbar-actionbar-tutorial/

Answer 3

I have a little problem with understanding menuInflater. This class instantiate menu XML files into Menu objects. But there set new menu

public boolean onCreateActionMode(ActionMode actionMode, Menu menu) { //when this method is going to be made? Menu is int the toolbar and ListView isn't connected with toolbar so which menu I get in the next next line?
    MenuInflater menuInflater = getMenuInflater();
    menuInflater.inflate(R.menu.toolbar_cab, menu); // in this line set a new menu
    return true;

}`

Answer 4

To hide RadioButton from RadioGroup is very simple. You just write btnRadio1.setVisibility(View.INVISIBLE);. BUT you have to know this rule: If you have, for example, 4 RadioButtons in RadioGroup, you can make them invisible in reverse order only! I mean the order they are defined in RadioGroup in your layout .xml file. It is impossible to hide btnRadio3 only, and btnRadio4 to be visible! You have to hide btnRadio3 and btnRadio4. Or only btnRadio4. So, if you want to hide 1 button, it is button 4. If you want to hide 2 buttons - they are 4 and 3. If you want to hide 3 buttons they are 4, 3, and 2. All other combinations, simply doesn't work. Here is code from my Quiz app, where every question may have from 2 to 6 answers. The answers of current question are stored in array of strings answers [].

RadioButton btnAnswer1;
RadioButton btnAnswer2;
RadioButton btnAnswer3;
RadioButton btnAnswer4;
RadioButton btnAnswer5;
RadioButton btnAnswer6;
RadioGroup  radioGroup;

// onCreate activity

btnAnswer1 = (RadioButton) findViewById(R.id.btnAnswer1);
btnAnswer2 = (RadioButton) findViewById(R.id.btnAnswer2);
btnAnswer3 = (RadioButton) findViewById(R.id.btnAnswer3);
btnAnswer4 = (RadioButton) findViewById(R.id.btnAnswer4);
btnAnswer5 = (RadioButton) findViewById(R.id.btnAnswer5);
btnAnswer6 = (RadioButton) findViewById(R.id.btnAnswer6);
radioGroup = (RadioGroup) findViewById(R.id.radioGroup);

radioGroup.clearCheck();


    btnAnswer1.setVisibility(View.VISIBLE);
    btnAnswer2.setVisibility(View.VISIBLE);
    numberOfAnswers = 2; //at least 2 answers
//if 3-d element is empty i.e. 2 answers only
//i.e. buttons 3,4,5,6 must be hidden              
    if (answers[2].isEmpty()) { 
        btnAnswer3.setVisibility(View.INVISIBLE);
        btnAnswer4.setVisibility(View.INVISIBLE);
        btnAnswer5.setVisibility(View.INVISIBLE);
        btnAnswer6.setVisibility(View.INVISIBLE);
    } else {
        btnAnswer3.setVisibility(View.VISIBLE);
        numberOfAnswers = 3;   
    }
    if (answers[3].isEmpty()) {
        btnAnswer4.setVisibility(View.INVISIBLE);
        btnAnswer5.setVisibility(View.INVISIBLE);
        btnAnswer6.setVisibility(View.INVISIBLE);
    } else {  
        btnAnswer4.setVisibility(View.VISIBLE);
        numberOfAnswers = 4;   
    } 
    if (answers[4].isEmpty()) {
        btnAnswer5.setVisibility(View.INVISIBLE);
        btnAnswer6.setVisibility(View.INVISIBLE);
    } else {  
        btnAnswer5.setVisibility(View.VISIBLE);
        numberOfAnswers = 5;   
    } 
    if (answers[5].isEmpty()) {
        btnAnswer6.setVisibility(View.INVISIBLE);
    } else {  
        btnAnswer6.setVisibility(View.VISIBLE);
        numberOfAnswers = 6;   
    } 

And here is xml file:

<ScrollView 
 android:layout_height="fill_parent"
 android:layout_width="fill_parent"
 android:layout_marginLeft="5dip"
 android:orientation="vertical">        

    <RadioGroup
        android:id="@+id/radioGroup"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >

        <RadioButton
            android:id="@+id/btnAnswer1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            />
        <RadioButton
            android:id="@+id/btnAnswer2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            />
        <RadioButton
            android:id="@+id/btnAnswer3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            />
        <RadioButton
            android:id="@+id/btnAnswer4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            />
        <RadioButton
            android:id="@+id/btnAnswer5"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            />
        <RadioButton
            android:id="@+id/btnAnswer6"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            />

    </RadioGroup>
</ScrollView>