Android - 如何使edittext中的所有行都加下划线?

问题描述

从教程中我创建了布局:

From the tutorial I have created the layout:

  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"
/>

这只会使第一行加下划线.即使编辑文本中只有一行，是否可以将所有行都加下划线?

This makes only the first line underlined. Is it possible to make all the lines underlined, even if there is only one line in the edtittext?

我尝试改变循环，例如for (int i = 0; i < 5; i++) 但随后我收到此错误:

I tried changing the loop e.g. for (int i = 0; i < 5; i++) but then I receive this error:

04-28 08:29:05.093: E/AndroidRuntime(14398):java.lang.IndexOutOfBoundsException: 2, 1 04-28 08:29:05.093:E/AndroidRuntime(14398):在android.text.PackedIntVector.getValue(PackedIntVector.java:70) 04-2808:29:05.093: E/AndroidRuntime(14398): 在android.text.DynamicLayout.getLineTop(DynamicLayout.java:367) 04-2808:29:05.093: E/AndroidRuntime(14398): 在android.text.Layout.getLineBottom(Layout.java:831) 04-28 08:29:05.093:E/AndroidRuntime(14398):在android.text.Layout.getLineBounds(Layout.java:437) 04-28 08:29:05.093:E/AndroidRuntime(14398):在android.widget.TextView.getLineBounds(TextView.java:4122) 04-2808:29:05.093: E/AndroidRuntime(14398): 在com.bbbfr.mynotepad.NotepadText$LinedEditText.onDraw(NotepadText.java:56)

04-28 08:29:05.093: E/AndroidRuntime(14398): java.lang.IndexOutOfBoundsException: 2, 1 04-28 08:29:05.093: E/AndroidRuntime(14398): at android.text.PackedIntVector.getValue(PackedIntVector.java:70) 04-28 08:29:05.093: E/AndroidRuntime(14398): at android.text.DynamicLayout.getLineTop(DynamicLayout.java:367) 04-28 08:29:05.093: E/AndroidRuntime(14398): at 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): at 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);

我还在视图中设置了 android:lines="5".

I have also set android:lines="5" in the view.

推荐答案

如果你不介意下划线与 EditText 中的文本颜色相同，你真的应该只是使用内置 UnderlineSpan，可以自己创建，也可以通过 Html.fromHtml(...) 间接创建.

private void createUnderlinedText() {
    String text = "I am underlined text
Line #2
Line #3
Line #4
Line #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));
}

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);
    }
}