易采站长站为您分析Android编程实现在Bitmap上涂鸦效果的方法,涉及Android界面布局,事件响应及Bitmap操作的相关技巧,具有一定参考借鉴价值,需要的朋友可以参考下
本文实例讲述了Android编程实现在Bitmap上涂鸦效果。，具体如下：
布局文件：
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://www.easck.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <LinearLayout android:id="@+id/handwriteview" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <LinearLayout android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="horizontal" android:gravity="center_horizontal" > <Button android:id="@+id/clear" android:layout_width="200dp" android:layout_height="wrap_content" android:text="清屏" /> </LinearLayout> </LinearLayout>
重写的View文件：
public class HandWrite extends View
{
private Paint paint = null;
private Bitmap originalBitmap = null;
private Bitmap new1Bitmap = null;
private Bitmap new2Bitmap = null;
private float clickX = 0,clickY = 0;
private float startX = 0,startY = 0;
private boolean isMove = true;
private boolean isClear = false;
private int color = Color.GREEN;
private float strokeWidth = 2.0f;
public HandWrite(Context context,Bitmap b)
{
super(context);
originalBitmap = Bitmap.createBitmap(b).copy(Bitmap.Config.ARGB_8888, true);
new1Bitmap = Bitmap.createBitmap(originalBitmap);
}
public void clear(){
isClear = true;
new2Bitmap = Bitmap.createBitmap(originalBitmap);
invalidate();
}
public void setstyle(float strokeWidth){
this.strokeWidth = strokeWidth;
}
@Override
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
canvas.drawBitmap(HandWriting(new1Bitmap), 0, 0,null);
}
public Bitmap HandWriting(Bitmap originalBitmap)
{
Canvas canvas = null;
if(isClear){
canvas = new Canvas(new2Bitmap);
}
else{
canvas = new Canvas(originalBitmap);
}
paint = new Paint();
paint.setStyle(Style.STROKE);
paint.setAntiAlias(true);
paint.setColor(color);
paint.setStrokeWidth(strokeWidth);
if(isMove){
canvas.drawLine(startX, startY, clickX, clickY, paint);
}
startX = clickX;
startY = clickY;
if(isClear){
return new2Bitmap;
}
return originalBitmap;
}
@Override
public boolean onTouchEvent(MotionEvent event)
{
clickX = event.getX();
clickY = event.getY();
if(event.getAction() == MotionEvent.ACTION_DOWN){
isMove = false;
invalidate();
return true;
}
else if(event.getAction() == MotionEvent.ACTION_MOVE){
isMove = true;
invalidate();
return true;
}
return super.onTouchEvent(event);
}
}
