在edittext中绘制多行，例如记事本 [英] Drawing multiple lines in edittext e.g. notepad

问题描述

我正在查看 android SDK 中的记事本示例，请参见此处:http://developer.android.com/resources/samples/NotePad/src/com/example/android/notepad/NoteEditor.html

I was taking a look at the notepad sample in the android SDK see here: http://developer.android.com/resources/samples/NotePad/src/com/example/android/notepad/NoteEditor.html

问题是它只绘制光标所在的当前行，例如 http://cdn2.staztic.com/screenshots/simple-notepad-app-al-1.jpg

Thing is it only draws the current line the cursor is on e.g http://cdn2.staztic.com/screenshots/simple-notepad-app-al-1.jpg

但我想显示填满屏幕的线条，例如http://www.itismyworld.info/wp-content/uploads/2010/03/AK-notebook.png

But I'd like to display lines that fill up the screen e.g. http://www.itismyworld.info/wp-content/uploads/2010/03/AK-notebook.png

任何建议都会很棒.相关的代码似乎在这里:

Any suggestions would be great. The relevent bit of code seems to be here:

    protected void onDraw(Canvas canvas) {

        // Gets the number of lines of text in the View.
        int count = getLineCount();

        // Gets the global Rect and Paint objects
        Rect r = mRect;
        Paint paint = mPaint;

        /*
         * Draws one line in the rectangle for every line of text in the EditText
         */
        for (int i = 0; i < count; i++) {

            // Gets the baseline coordinates for the current line of text
            int baseline = getLineBounds(i, r);

            /*
             * Draws a line in the background from the left of the rectangle to the right,
             * at a vertical position one dip below the baseline, using the "paint" object
             * for details.
             */
            canvas.drawLine(r.left, baseline + 1, r.right, baseline + 1, paint);
        }

        // Finishes up by calling the parent method
        super.onDraw(canvas);
    }

推荐答案

这是代码，基于 jkhouws1 的建议和 google 的 笔记编辑器

This is the code, based on jkhouws1's suggestion and google's note editor

public 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.FILL_AND_STROKE);
        mPaint.setColor(R.color.edit_note_line); //SET YOUR OWN COLOR HERE
    }

    @Override
    protected void onDraw(Canvas canvas) {
        //int count = getLineCount();

        int height = getHeight();
        int line_height = getLineHeight();

        int count = height / line_height;

        if (getLineCount() > count)
            count = getLineCount();//for long text with scrolling

        Rect r = mRect;
        Paint paint = mPaint;
        int baseline = getLineBounds(0, r);//first line

        for (int i = 0; i < count; i++) {

            canvas.drawLine(r.left, baseline + 1, r.right, baseline + 1, paint);
            baseline += getLineHeight();//next line
        }

        super.onDraw(canvas);
    }
}

在 Eclipse IDE 中按 Ctrl+Shift+O 添加所有需要的导入

In Eclipse IDE press Ctrl+Shift+O to add all needed imports

这篇关于在edittext中绘制多行，例如记事本的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！