无法解析“ setEnabled”方法。 Android工作室

Question

I am pretty new to android studio. So I apologize for the newbie kind of question. I have been reading posts on how to use the setEnabled(); method to enable and disable a bottom. As you will be able to see in the code, I am trying to enable a previously disabled button (through xml using android:enabled="false"/> ) Whenever one of the Radiobuttons in a radioGroup is selected.

The 'setEnabled' part of the code gets highlighted in red and errors pop: cannot resolve method ' setEnabled(boolean) '

Here is the code. I'd like to know why this is not working and how to fix it, rather than just the answer itself. Thank you in advance

    public void onRadioButtonClicked(View view) {
    // Is the button now checked?
    boolean checked = ((RadioButton) view).isChecked();

    // Check which radio button was clicked
    switch(view.getId()) {
        case R.id.radioButtonYes:
            if (checked)
                R.id.buttonNEXT.setEnabled(true);
            break;
        case R.id.radioButtonNo:
            if (checked)
                R.id.buttonNEXT.setEnabled(true);
                break;
        case R.id.radioButtonDontknow:
            if (checked)
                R.id.buttonNEXT.setEnabled(true);
                break;
    }

Answer 1

Don't

R.id.buttonNEXT.setEnabled(true);

DO

((Button) findViewById(R.id.buttonNEXT)).setEnabled(true); 

Finally :

switch(view.getId()) {
    case R.id.radioButtonYes:
        if (checked)
            ((Button) findViewById(R.id.buttonNEXT)).setEnabled(true); 
            break;

Answer 2

What you are trying to use setEnabled() with an int , which is not possible as R.id.someId is of int type. Better to find a view for that id and then use setEnabled() .

This will work fine,

((Button) findViewById(R.id.buttonNEXT)).setEnabled(true);

Answer 3

this is wrong

R.id.buttonNEXT.setEnabled(true);

R.id.buttonNEXT is the id (just an integer) that you have to use to create a Button

you should need to do something like

 Button myButton = (Button)findViewById(R.id.buttonNEXT);

THEN after that you can invoke all the method a Buttom has

if (checked)
      myButton.setEnabled(true);

Answer 4

You should use it like this

public void onRadioButtonClicked(View view) {
    // Is the button now checked?
    boolean checked = ((RadioButton) view).isChecked();
    Button b=(Button)findViewById(R.id.buttonNEXT); //casted to button. use the type is used
    // Check which radio button was clicked
    switch(view.getId()) {
        case R.id.radioButtonYes:
            if (checked)
                b.setEnabled(true); //change to this
            break;
        case R.id.radioButtonNo:
            if (checked)
                b.setEnabled(true); //change to this
                break;
        case R.id.radioButtonDontknow:
            if (checked)
                b.setEnabled(true); //change to this
                break;
    }