如何更新画布绘制文本而不是重绘画布

Question

我现在可以在运动视图的画布上绘制文本问题是，当我绘制文本并在同一画布上进行下一次绘制时，我的绘制文本消失了我的意思是屏幕因无效而重新绘制，我想保留我以前的在同一个画布上绘制并进行新的绘制，我该怎么做？

@Override
   protected void onDraw(Canvas canvas) {
    Paint hint = new Paint();
    path = new Path();
    mTextPaths = new ArrayList<Path>();
    Log.v("getting mtextpaths", mTextPaths.toString());

    int m;
    if (strgettile != null) {
        for (m = 0; m < strgettile.length(); m++) {
            System.out.println(strgettile.charAt(m));
            char convertst = strgettile.charAt(m);
            characterToString = Character.toString(convertst);

            // canvas.drawText(characterToString, x, y, hint);
            // canvas.drawText(characterToString, m
            // * width + x, m * height + y, foreground); //its working in
            // cross
            // canvas.drawText(characterToString, x, m * height + y,
            // foreground); //its working for vertical
            // canvas.drawText(characterToString, m
            // * width + x, y, foreground); //its working in horizontal
            // setSelectedTile(tile);
            if (getorientation.equalsIgnoreCase("Horizontal")) {
                canvas.drawText(characterToString, m * width + positionX,
                        positionY, foreground); // for motion event
                hint.setColor(Color.BLACK);
                hint.setTextSize(45);
                foreground.getTextPath(characterToString, 0,
                        characterToString.length(), positionX * 2 / 3,
                        positionY - 4, path);

            } else {
                canvas.drawText(characterToString, positionX, m * height
                        + positionY, foreground);
                hint.setColor(Color.BLACK);
                hint.setTextSize(45);
                foreground.getTextPath(characterToString, 0,
                        characterToString.length(), positionX * 2 / 3,
                        positionY - 4, path);


            }


        }

    }

  public void setSelectedTile(String tile, String strorientations) {
    // TODO Auto-generated method stub
    Log.v("getting string in puzzle view ", tile);
    strgettile = tile;
    getorientation = strorientations;
    mTextPaths.add(path);
    invalidate();


}

Answer 1

我不会阅读那些包含所有不相关事件处理的过长且格式可怕的代码......但一般来说，如果您想在绘制之间保存画布状态，您需要明确地执行此操作。

谷歌“屏幕绘图的android”

Android 中的离屏绘图

在位图上绘制。在画布上绘制该位图。重复。