Android - 如何使edittext中的所有行加下划线？

Question

从教程我创建了布局:

  public static class LinedEditText extends EditText {
        private Rect mRect;
        private Paint mPaint;

        // we need this constructor for LayoutInflater
        public LinedEditText(Context context, AttributeSet attrs) {
            super(context, attrs);

            mRect = new Rect();
            mPaint = new Paint();
            mPaint.setStyle(Paint.Style.STROKE);
            mPaint.setColor(0x80000000);
        }

        @Override
        protected void onDraw(Canvas canvas) {
            int count = getLineCount();
            Rect r = mRect;
            Paint paint = mPaint;

            for (int i = 0; i < count; i++) {
                int baseline = getLineBounds(i, r);
                canvas.drawLine(r.left, baseline + 1, r.right, baseline + 1, paint);
            }

            super.onDraw(canvas);
        }
    }

<view xmlns:android="http://schemas.android.com/apk/res/android"
    class="com.bbbfr.mynotepad.NotepadText$LinedEditText"
    android:id="@+id/note"
    android:background="#ffd6e5"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:padding="5dp"
    android:scrollbars="vertical"
    android:fadingEdge="vertical"
    android:gravity="top"
    android:textSize="22sp"
    android:textColor="#000000"
    android:inputType="textMultiLine"
    android:capitalize="sentences"
/>

这使得第一行只有下划线.即使edtittext中只有一行,是否可以使所有行加下划线？

我尝试更改循环, for (int i = 0; i < 5; i++)但后来我收到此错误:

04-28 08:29:05.093:E/AndroidRuntime(14398):java.lang.IndexOutOfBoundsException:2,104-28 08:29:05.093:E/AndroidRuntime(14398):at android.text.PackedIntVector.getValue( PackedIntVector.java:70)04-28 08:29:05.093:E/AndroidRuntime(14398):在android.text.DynamicLayout.getLineTop(DynamicLayout.java:367)04-28 08:29:05.093:E/AndroidRuntime( 14398):在android.text.Layout.getLineBottom(Layout.java:831)04-28 08:29:05.093:E/AndroidRuntime(14398):at android.text.Layout.getLineBounds(Layout.java:437)04 -28 08:29:05.093:E/AndroidRuntime(14398):在android.widget.TextView.getLineBounds(TextView.java:4122)04-28 08:29:05.093:E/AndroidRuntime(14398):at com.bbbfr .mynotepad.NotepadText $ LinedEditText.onDraw(NotepadText.java:56)

到这一行: int baseline = getLineBounds(i, r);

我也在android:lines="5"视图中设置了.

Answer 1

如果您不介意下划线与文本中的文本具有相同的颜色EditText,您应该只使用内置UnderlineSpan,可以通过自己创建或间接创建Html.fromHtml(...).

private void createUnderlinedText() {
    String text = "I am underlined text\nLine #2\nLine #3\nLine #4\nLine #5";

    EditText underlineSpanEditText = (EditText) findViewById(R.id.underlinespan_edittext);
    SpannableStringBuilder sb = new SpannableStringBuilder(text);
    sb.setSpan(new UnderlineSpan(), 0, text.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
    underlineSpanEditText.setText(sb);

    EditText htmlUnderlineEditText = (EditText) findViewById(R.id.html_underline_edittext);
    String html = "<u>I am underlined text</br>Line #2</br>Line #3</br>Line #4</br>Line #5</u>";
    htmlUnderlineEditText.setText(Html.fromHtml(html));
}

与当前方法的主要区别在于,这只会强调实际文本,而不是整个文本行.例如,如果您运行我的代码片段,您会发现当下划线被\n或中断时,下划线不会延伸到行尾<br/>.但是,根据您的行为,这可能不是您想要的.

编辑:所以,如果我理解正确,你基本上想要在你的水平线上画画EditText,无论是否有文字？你的问题中的"下划线"部分有点误导,因为事实证明,这与它没什么关系(在单词:)的传统意义上).

无论如何,你不能使用,getLineCount()因为它总是返回包含实际文本的行数.这意味着你必须用新行字符"填充"任何剩余空间才能获得理想的效果,这听起来有点令人讨厌......一个更好的选择可能是将水平线的绘制基于总高度EditText.一个简单的例子,您可以根据自己的喜好进行调整:

public class LinedEditText extends EditText {
    private Paint mPaint = new Paint();

    public LinedEditText(Context context) {
        super(context);
        initPaint();
    }

    public LinedEditText(Context context, AttributeSet attrs) {
        super(context, attrs);
        initPaint();
    }

    public LinedEditText(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        initPaint();
    }

    private void initPaint() {
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setColor(0x80000000);
    }

    @Override protected void onDraw(Canvas canvas) {
        int left = getLeft();
        int right = getRight();
        int paddingTop = getPaddingTop();
        int paddingBottom = getPaddingBottom();
        int paddingLeft = getPaddingLeft();
        int paddingRight = getPaddingRight();
        int height = getHeight();
        int lineHeight = getLineHeight();
        int count = (height-paddingTop-paddingBottom) / lineHeight;

        for (int i = 0; i < count; i++) {
            int baseline = lineHeight * (i+1) + paddingTop;
            canvas.drawLine(left+paddingLeft, baseline, right-paddingRight, baseline, mPaint);
        }

        super.onDraw(canvas);
    }
}

结果如下: