Android - 编辑文本 - 下划线

Question

有没有办法让多行编辑文本中的所有行都加下划线？ 我希望所有行都显示该行，即使上面没有文字。

Answer 1

这种事情是在Notepad 示例演示中完成的。如果我们查看editor source，我们可以看到他们使用自定义文本编辑器，如下所示：

/**
 * A custom EditText that draws lines between each line of text that is displayed.
 */
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(0x800000FF);
    }

    @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);
    }
}

然后他们在layout 中以这种方式声明：

<view xmlns:android="http://schemas.android.com/apk/res/android"
    class="com.example.android.notepad.NoteEditor$LinedEditText"
    android:id="@+id/note"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@android:color/transparent"
    android:padding="5dp"
    android:scrollbars="vertical"
    android:fadingEdge="vertical"
    android:gravity="top"
    android:textSize="22sp"
    android:capitalize="sentences" />