Android MyView(FingerPaint演示)重置画布
我已经使用了FingerPaint API演示(从)中的MyView类,并且希望能够清除任何绘制线的视图。实际上,将其重置为活动开始时第一次呈现的时间。MyView视图在我的XML布局中声明(未编程) 用按钮做这件事最简单的方法是什么Android MyView(FingerPaint演示)重置画布,android,canvas,view,reset,Android,Canvas,View,Reset,我已经使用了FingerPaint API演示(从)中的MyView类,并且希望能够清除任何绘制线的视图。实际上,将其重置为活动开始时第一次呈现的时间。MyView视图在我的XML布局中声明(未编程) 用按钮做这件事最简单的方法是什么 非常感谢:)我通过修改MyView类实现了这一点,如下所示: import java.util.ArrayList; import java.util.List; import android.content.Context; import android.gr
非常感谢:)我通过修改MyView类实现了这一点,如下所示:
import java.util.ArrayList;
import java.util.List;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
public class MyView extends View {
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
private Paint mPaint;
private List<Path> mPathsArray = new ArrayList<Path>();
public MyView(Context c, AttributeSet attrs) {
super(c, attrs);
mPaint = new Paint();
mPaint.setColor(0xFF00F1F5);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(6);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
}
public void clear(){
mBitmap = Bitmap.createBitmap(480, 480, Bitmap.Config.ARGB_8888);
mPath = new Path();
invalidate();
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
}
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
private void touch_start(float x, float y) {
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
mX = x;
mY = y;
}
}
private void touch_up() {
mPath.lineTo(mX, mY);
// commit the path to our offscreen
mCanvas.drawPath(mPath, mPaint);
// kill this so we don't double draw
mPathsArray.add(mPath);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touch_up();
invalidate();
break;
}
return true;
}
}
import java.util.ArrayList;
导入java.util.List;
导入android.content.Context;
导入android.graphics.Bitmap;
导入android.graphics.Canvas;
导入android.graphics.Paint;
导入android.graphics.Path;
导入android.util.AttributeSet;
导入android.view.MotionEvent;
导入android.view.view;
公共类MyView扩展了视图{
私有位图mBitmap;
私人帆布mCanvas;
专用路径mPath;
私人油漆;
私人油漆;
私有列表mPathsArray=newarraylist();
公共MyView(上下文c、属性集属性){
super(c,attrs);
mPaint=新油漆();
mPaint.setColor(0xFF00F1F5);
mPaint.setStyle(油漆、样式、笔划);
mPaint.setStrokeJoin(油漆.连接.圆形);
mPaint.setStrokeCap(油漆盖圆形);
mPaint.设定行程宽度(6);
mPath=新路径();
mBitmapPaint=新油漆(油漆抖动标志);
}
@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){
super.onSizeChanged(w,h,oldw,oldh);
mBitmap=Bitmap.createBitmap(w,h,Bitmap.Config.ARGB_8888);
mCanvas=新画布(mBitmap);
}
公共空间清除(){
mBitmap=Bitmap.createBitmap(480480,Bitmap.Config.ARGB_8888);
mPath=新路径();
使无效();
}
@凌驾
受保护的void onDraw(画布){
drawBitmap(mBitmap,0,0,mbitMapPoint);
画布绘制路径(mPath,mPaint);
}
私人浮动mX,我的;
专用静态最终浮动接触公差=4;
专用无效触摸启动(浮动x、浮动y){
移动到(x,y)的速度;
mX=x;
mY=y;
}
私有无效触摸移动(浮动x、浮动y){
float dx=Math.abs(x-mX);
float dy=Math.abs(y-mY);
如果(dx>=接触公差| | dy>=接触公差){
兆帕四分之一秒(mX,mY,(x+mX)/2,(y+mY)/2);
mX=x;
mY=y;
}
}
私人空间修补(){
mPath.lineTo(mX,mY);
//将路径提交到我们的屏幕外
mCanvas.drawPath(mPath,mPaint);
//杀了它,这样我们就不会重复抽签了
mPathsArray.add(mPath);
}
@凌驾
公共布尔onTouchEvent(运动事件){
float x=event.getX();
float y=event.getY();
开关(event.getAction()){
case MotionEvent.ACTION\u DOWN:
触摸启动(x,y);
使无效();
打破
case MotionEvent.ACTION\u移动:
触摸移动(x,y);
使无效();
打破
case MotionEvent.ACTION\u UP:
润色;
使无效();
打破
}
返回true;
}
}
只是以防万一其他人想要达到同样的效果