用于显示可滚动多行文本的最佳Android控件

Question

I'm starting to write an ebook type of program in Android and don't know the best alternative to Apple's UITextView.

It needs to display multiline read-only text and be scrollable.

Answer 1

You already know this class - it is TextView - you can adjust it to be scrollable.

In XML view template put android:scrollbars="vertical" :

<TextView 
    android:id="@+id/myText"
    android:scrollbars="vertical"

In java code put then:

mTextView = (TextView) findViewById(R.id.myText);
mTextView.setMovementMethod(ScrollingMovementMethod.getInstance());

If you want your TextView to scroll automatically to the bottom after the text is changed, add the code like below:

mTextView.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) {
        scrollToLastLine(mTextView);
    }

    private void scrollToLastLine(TextView tv) {
        int scrollY = 0;
        if (!TextUtils.isEmpty(tv.getText())) {
            final int linesCount = tv.getLineCount();
            if (linesCount > 0) {
                scrollY = Math.max(0,
                        tv.getLayout().getLineTop(linesCount)
                                - tv.getHeight());
            }
        }
        tv.scrollTo(0, scrollY);
    }
});