Android 撤消重做功能不起作用。
我正在为android用户开发一个绘图应用程序。我想在我的应用程序上实现撤消重做功能。我在引用stackoverflow上发布的问题来解决我的问题,但我无法为我的代码找到正确的解决方案。下面我发布我的代码,请帮助我摆脱这个问题。任何帮助将不胜感激 先谢谢你Android 撤消重做功能不起作用。,android,android-view,undo,redo,Android,Android View,Undo,Redo,我正在为android用户开发一个绘图应用程序。我想在我的应用程序上实现撤消重做功能。我在引用stackoverflow上发布的问题来解决我的问题,但我无法为我的代码找到正确的解决方案。下面我发布我的代码,请帮助我摆脱这个问题。任何帮助将不胜感激 先谢谢你 public class DrawingView extends View { private ArrayList<Path> paths = new ArrayList<Path>(); private Arr
public class DrawingView extends View {
private ArrayList<Path> paths = new ArrayList<Path>();
private ArrayList<Path> undonePaths = new ArrayList<Path>();
public DrawingView(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
this.context = context;
setupDrawing();
}
public void setupDrawing(){
drawPath = new Path();
drawPaint = new Paint();
canvasPaint = new Paint(Paint.DITHER_FLAG);
brushSize = getResources().getInteger(R.integer.medium_size);
lastBrushSize = brushSize;
drawPaint.setColor(paintColor);
drawPaint.setAntiAlias(true);
drawPaint.setStrokeWidth(brushSize);
drawPaint.setStyle(Paint.Style.STROKE);
drawPaint.setStrokeJoin(Paint.Join.ROUND);
drawPaint.setStrokeCap(Paint.Cap.ROUND);
paths.add(drawPath);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
//view given size
super.onSizeChanged(w, h, oldw, oldh);
canvasBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
drawCanvas = new Canvas(canvasBitmap);
}
@Override
protected void onDraw(Canvas canvas) {
//draw view
canvas.drawBitmap(canvasBitmap, 0, 0, canvasPaint);
canvas.drawPath(drawPath, drawPaint);
for(Path p : paths){
canvas.drawPath(p, drawPaint);
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float touchX = event.getX();
float touchY = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
// undonePaths.clear();
drawPath.moveTo(touchX, touchY);
break;
case MotionEvent.ACTION_MOVE:
drawPath.lineTo(touchX, touchY);
break;
case MotionEvent.ACTION_UP:
// drawPath.lineTo(touchX, touchY);
drawCanvas.drawPath(drawPath, drawPaint);
drawPath.reset();
drawPath = new Path();
paths.add(drawPath);
break;
default:
return false;
}
invalidate();
return true;
}
public void onClickUndo(){
if(paths.size()>0){
undonePaths.add(paths.remove(paths.size() - 1));
Toast.makeText(getContext(), "Undo is working", Toast.LENGTH_LONG).show();
invalidate();
}
else{
Toast.makeText(getContext(), "Undo is not working", Toast.LENGTH_LONG).show();
}
}
public void onClickRedo(){
if(undonePaths.size()>0){
paths.add(undonePaths.remove(undonePaths.size() - 1));
Toast.makeText(getContext(), "Redo is working", Toast.LENGTH_LONG).show();
invalidate();
}
else{
Toast.makeText(getContext(), "Redo is not working", Toast.LENGTH_LONG).show();
}
}
}
公共类DrawingView扩展视图{
私有ArrayList路径=新ArrayList();
private ArrayList undonePaths=new ArrayList();
公共绘图视图(上下文、属性集属性){
超级(上下文,attrs);
//TODO自动生成的构造函数存根
this.context=上下文;
设置绘图();
}
公共图纸(){
drawPath=新路径();
drawPaint=新油漆();
画布绘制=新绘制(绘制抖动标志);
brushSize=getResources().getInteger(R.integer.medium\u size);
lastBrushSize=笔刷大小;
drawPaint.setColor(paintColor);
drawPaint.setAntiAlias(真);
drawPaint.设置行程宽度(刷号);
drawPaint.setStyle(Paint.Style.STROKE);
drawPaint.setStrokeJoin(绘制.连接.圆形);
drawPaint.setStrokeCap(油漆盖圆形);
添加(drawPath);
}
@凌驾
已更改尺寸的受保护空心(整数w、整数h、整数oldw、整数oldh){
//查看给定的大小
super.onSizeChanged(w,h,oldw,oldh);
canvasBitmap=Bitmap.createBitmap(w,h,Bitmap.Config.ARGB_8888);
drawCanvas=新画布(画布位图);
}
@凌驾
受保护的void onDraw(画布){
//绘图视图
drawBitmap(canvasBitmap,0,0,canvasPaint);
canvas.drawPath(drawPath,drawPaint);
用于(路径p:路径){
画布.drawPath(p,drawPaint);
}
}
@凌驾
公共布尔onTouchEvent(运动事件){
float touchX=event.getX();
float touchY=event.getY();
开关(event.getAction()){
case MotionEvent.ACTION\u DOWN:
//撤销海王星。清除();
drawPath.moveTo(touchX,toucy);
打破
case MotionEvent.ACTION\u移动:
drawPath.lineTo(touchX,touchY);
打破
case MotionEvent.ACTION\u UP:
//drawPath.lineTo(touchX,touchY);
drawCanvas.drawPath(drawPath,drawPaint);
drawPath.reset();
drawPath=新路径();
添加(drawPath);
打破
违约:
返回false;
}
使无效();
返回true;
}
公共void onClickUndo(){
if(path.size()>0){
undonePaths.add(path.remove(path.size()-1));
Toast.makeText(getContext(),“撤消正在工作”,Toast.LENGTH_LONG.show();
使无效();
}
否则{
Toast.makeText(getContext(),“撤消不起作用”,Toast.LENGTH_LONG.show();
}
}
public void onClickRedo(){
如果(撤消路径大小()>0){
add(undonePaths.remove(undonePaths.size()-1));
Toast.makeText(getContext(),“重做正在工作”,Toast.LENGTH_LONG.show();
使无效();
}
否则{
Toast.makeText(getContext(),“重做不起作用”,Toast.LENGTH_LONG.show();
}
}
}
只是一些小改动
在您的列表中有一个额外的路径
,当其他步骤被纠正时,该路径将导致撤销/重做步骤实际上什么也不做。因此,在setupDrawing()中删除:
paths.add(drawPath);
在onDraw()方法中,删除:
canvas.drawBitmap(canvasBitmap, 0, 0, canvasPaint);
此drawBitmap()
调用正在重新绘制在每个操作上绘制到的成员位图,使其看起来好像您的路径
列表没有被更新
然后,在onTouchEvent()
方法中的MotionEvent.ACTION\u DOWN
un comment:
undonePaths.clear();
并将MotionEvent.ACTION\u UP
案例更改为:
case MotionEvent.ACTION_UP:
drawCanvas.drawPath(drawPath, drawPaint);
paths.add(drawPath);
drawPath = new Path();
break;
reset()
调用正在清除您不需要的路径。相反,这里我们将最近完成的路径添加到列表中,然后创建一个新路径以继续
注意:按照目前的工作方式,撤消/重做功能不会影响画布位图
。由于不清楚这个位图的用途,我将它保留原样。如果希望此位图镜像视图,只需将drawCanvas.drawPath()
调用移动到onDraw()
,与那里的canvas.drawPath()
调用并行。var undoRedo=new Array();
var undoRedo = new Array();
var unStep = -1;
function historySave() {
unStep++;
while (undoRedo.length > 20) {
undoRedo.shift();
unStep--;
}
if (unStep !== 0 && unStep < undoRedo.length) {
undoRedo.length = unStep;
unStep++;
} else {
undoRedo.length = unStep;
}
undoRedo.push(document.getElementById('drawingCanvas').toDataURL());
}
function Undo() {
if (unStep > -1) {
unStep--;
var canvasPic = new Image();
canvasPic.src = undoRedo[unStep];
drawingContext.clearRect(0,0,drawingCanvas.width,drawingCanvas.height);
canvasPic.onload = function () {
drawingContext.drawImage(canvasPic, 0, 0);
}
}
}
function Redo() {
if (unStep < undoRedo.length - 1) {
unStep++;
var canvasPic = new Image();
canvasPic.src = undoRedo[unStep];
canvasPic.onload = function () {
drawingContext.drawImage(canvasPic, 0, 0);
}
}
}
var unStep=-1;
函数historySave(){
unStep++;
while(undoRedo.length>20){
undoRedo.shift();
取消步骤--;
}
if(unStep!==0&&unStep-1){
取消步骤--;
var canvasPic=新图像();
canvasPic.src=undoRedo[unStep];
clearRect(0,0,drawingCanvas.width,drawingCanvas.height);
canvasPic.onload=函数(){
drawingContext.drawImage(canvasPic,0,0);
}
}
}
函数Redo(){
如果(取消步进
单击“撤消”时发生了什么?它是说“撤销不起作用”还是说你有一些不想要的效果?你的代码在没有画布的情况下工作得很好。但我需要让它和画布一起工作。我指的是本教程。请建议我也使用canvasBitmap。canvasBitmap的作用是什么?也就是说,它的功能是什么?它是一个模式填充位图,我可以通过手指触摸来选择和绘制。请参阅此链接。有些图案像草地和天空位图。“这是一个填充图案的位图”-不,不是。它是一个“缓冲区”,用于在onDraw()调用之间保存视图的图像