How to disable checkbox when a limit is reached in android?

问题

I have 15 CheckBox and I must to stuck user when he checks more than 5. I use the method OnCheckedChangeListener to know if an item is checked, but I don't know how to limit after 5 items selected.

See my code below:

int lengthBox = 15;
int lenghtCount = 0;  

// inside onCreate method
final CheckBox[] checkbox = new CheckBox[lengthBox];
OnCheckedChangeListener checker = new OnCheckedChangeListener(){ 
    @Override
    public void onCheckedChanged(CompoundButton cb, boolean b) {
        // How can I improve this condition?
        if(checkbox[0].isChecked() || checkbox[1].isChecked() || 
        checkbox[2].isChecked() || checkbox[3].isChecked() || 
        checkbox[4].isChecked() || checkbox[5].isChecked() || 
        checkbox[6].isChecked() || checkbox[7].isChecked() || 
        checkbox[8].isChecked() || checkbox[9].isChecked() || 
        checkbox[10].isChecked() || checkbox[11].isChecked() || 
        checkbox[12].isChecked() || checkbox[13].isChecked() || 
        checkbox[14].isChecked()) {  
            if(lenghtCount < 5){
                lenghtCount++;
            }else{
                Toast.makeText(MyActivity.this, "Limit reached!!!", Toast.LENGTH_SHORT).show();
            }
        }
    }
};
for(int i = 0; i < lengthBox; i++) {
    int id = getResources().getIdentifier("checkbox_"+i, "id", getPackageName());
    checkbox[i] = (CheckBox) findViewById(id)
    checkbox[i].setOnCheckedChangeListener(checker);
}

Can someone point me in the right way, please?

---

UPDATE: I tried:

OnCheckedChangeListener checker = new OnCheckedChangeListener(){ 
    @Override
    public void onCheckedChanged(CompoundButton cb, boolean b) {
        if(lenghtCount == 5){
            cb.setChecked(false);
        }else if(b){
            lenghtCount++;
        }else if(!b){
            lenghtCount--;
        }
    }
};  

Works perfectly but I think something is missing. When I click 5 items this works, but after when I unselect them, I can't recheck any item. What I'm missing?

回答1:

you should use a other variable for counting number of checkboxs that checked

final int count=0; 
OnCheckedChangeListener checker = new OnCheckedChangeListener(){ 
        @Override
        public void onCheckedChanged(CompoundButton cb, boolean b) {
           if(count == maxLimit && b){
               cb.setChecked(false);
               Toast.makeText(getApplicationContext(), 
            "Limit reached!!!", Toast.LENGTH_SHORT).show();
           }else if(b){

                count++;
                CharSequence myCheck = tagsCheck[i].getText();
                Toast.makeText(getApplicationContext(), 
                       myCheck + " checked!", 
                       Toast.LENGTH_SHORT)
                .show();
            }else if(!b){
 count--;
        }
    }; 

回答2:

I am not sure but something like this might help you. create a global count variable and every time a checkbox is checked, increase count by 1 and once count reaches max, disable further checks. Do something like this :

      OnCheckedChangeListener checker = new OnCheckedChangeListener(){ 
        @Override
        public void onCheckedChanged(CompoundButton cb, boolean b) {
           if(checkedCount == maxLimit){
               // set to unchecked and return. there must be some method for that 
               // like : setChecked(0) or some other method.
               return;
           }
           if(.isChecked()){

                checkedCount++;
                CharSequence myCheck = tagsCheck[i].getText();
                Toast.makeText(getApplicationContext(), 
                       myCheck + " checked!", 
                       Toast.LENGTH_SHORT)
                .show();
            }
        }
    };    

回答3:

Try this.. Create int check = 0; as global

OnCheckedChangeListener checker = new OnCheckedChangeListener(){ 
    @Override
    public void onCheckedChanged(CompoundButton cb, boolean b) {
   if(isChecked)
    {
        check ++;
        Toast.makeText(getApplicationContext(), 
                   myCheck + " checked! " +buttonView.getText(), 
                   Toast.LENGTH_SHORT)
            .show();            
    }
    else
    {
        check --;
        Toast.makeText(getApplicationContext(), 
                   myCheck + "Un checked! " +buttonView.getText(), 
                   Toast.LENGTH_SHORT)
            .show();    

    }


    if(check >= 5)
    {
        Toast.makeText(getApplicationContext(), 
                   myCheck + "Checked 5", 
                   Toast.LENGTH_SHORT)
            .show();
    }   
    }
};  

回答4:

Suppose You Have To Select Maximum 2 CheckBoxes Out OF 4 Then Following Code Is Useful:-

    Checkbox[] CBA = new CheckBox[4];
    int Count=0;
    CBA[0]=findViewByID(R.id.C1);
    CBA[1]=findViewByID(R.id.C2);
    CBA[2]=findViewByID(R.id.C3);
    CBA[3]=findViewByID(R.id.C4);
    CBA[0].setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener()
    @Override
    public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
    for(int i=0;i<CBA.length;i++)
        if(CBA[i].isChecked)
        {
         Count++;
        } 
    if(Count>2)
    {
     CBA[0].setCheck(false);
    }                       
    }

);

Do Same for Another 3 Checkbox You Can Also Do This By Using Checkchanged Listener To Whole Array(CBA[i].setOnCheckedChangeListener)............Hope It Will Be Useful

来源：https://stackoverflow.com/questions/20040638/how-to-disable-checkbox-when-a-limit-is-reached-in-android