Question

我在Android中使用了一个相当简单的自定义寻呼机适配器，我想跟踪edittext字段的内容，以便每个新幻灯片在输入时保留相同的文本。有人对此有任何见解吗？我猜我需要设置一个用于文本更改的监听器，但我不确定在哪里放置它。这是我的适配器：

private class CustomPagerAdapter extends PagerAdapter {

    public int getCount() {
        return 3;
    }

    public Object instantiateItem(ViewGroup collection, int position) {

        LayoutInflater inflater = (LayoutInflater) collection.getContext()
                .getSystemService(LAYOUT_INFLATER_SERVICE);
        View view;

        switch(position) {
            case 0:
                view = inflater.inflate(R.layout.slide0, null, false);
                break;
            case 1:
                view = inflater.inflate(R.layout.slide1, null, false);
                break;
            case 2:
                view = inflater.inflate(R.layout.slide2, null, false);
                break;
            default:
                view = inflater.inflate(R.layout.slide0, null, false);
        }
        collection.addView(view,0);

        return view;
    }



    @Override
    public void destroyItem(ViewGroup arg0, int arg1, Object arg2) {
        arg0.removeView((View) arg2);
    }
    @Override
    public boolean isViewFromObject(View arg0, Object arg1) {
        return arg0 == arg1;
    }
    @Override
    public Parcelable saveState() {
        return null;
    }

    @Override
    public void setPrimaryItem(ViewGroup container, int position, Object object) {
        super.setPrimaryItem(container, position, object);
        mCurrentSlide = (View) object;

    }
}

Answer 1

好的，我就是这样做的：

在主类中设置成员变量：

mText = "";

在适配器类的instantiateItem（）中设置textWatcher：

EditText edtSlide = (EditText)view.findViewById(R.id.edtSlide);
//Set a listener for the editText that updates the member variable on keystroke.
    TextWatcher tw = new TextWatcher() {

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            mText = s.toString();
        }

        };

    edtSlide.addTextChangedListener(tw);

然后在适配器类的setPrimaryItem（）方法中：

@Override
public void setPrimaryItem(ViewGroup container, int position, Object object) {
    super.setPrimaryItem(container, position, object);
    EditText text = (EditText)((View) object).findViewById(R.id.edtSlide);
    text.setText(mText);
}

Answer 2

创建一个TextWatcher，然后将其添加到每个EditText：

TextWatcher tw = new TextWatcher() {

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {                   
            }

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count,
                    int after) {                    
            }

            @Override
            public void afterTextChanged(Editable s) {
            // Save the text to some global variable
            }
        };

EditText et = (EditText) findViewById(R.id.editText1);
EditText et2 = (EditText) findViewById(R.id.editText2);

et.addTextChangedListener(tw);
et2.addTextChangedListener(tw);

修改

在上面的代码中，没有简单的方法可以知道哪个EditText调用了该事件。在这种情况下，您需要为每个EditText提供自己的TextWatcher：

et1.addTextChangedListener(new TextWatcher() { @Override public void onTextChanged(CharSequence s, int start, int before, int count) { } @Override public void beforeTextChanged(CharSequence s, int start, int count, int after) { } @Override public void afterTextChanged(Editable s) { global_string_variable_for_et1 = s.toString(); } });

<强> EDIT2：

TextWatcher[] tw = new TextWatcher[12]; for (int i = 0; i < tw.length; i++) { tw[i] = new TextWatcher() { @Override public void onTextChanged(CharSequence s, int start, int before, int count) {} @Override public void beforeTextChanged(CharSequence s, int start, int count, int after) {} @Override public void afterTextChanged(Editable s) { // Save the text to some global variable array txt_array[i] = s.toString(); } }; } for (int i = 0; i < et.length; i++) {7 et[i].addTextChangedListener(tw[i]); }

Answer 3

我可以通过放置TextWatcher来获得它，如下所示。

notes = (EditText) itemView.findViewById(R.id.notesText);

    TextWatcher textWatcher = new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

        }

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
            notedEnteredByUser = charSequence.toString();
            Log.i("TEXTWATCHER", notedEnteredByUser);
        }

        @Override
        public void afterTextChanged(Editable editable) {

        }
    };
    notes.addTextChangedListener(textWatcher);

在instantiateItem中，我正在使用String notedEnteredByUser。

如何在PagerAdapter幻灯片中跟踪edittext字段？

3 个答案: