Android实现画板、写字板功能（附源码下载）

前言

本文给大家分享一个使用Android开发写字板功能Dem、简单操作内存中的图像、对图像进行简单的处理、绘制直线、以达到写字板的效果

效果图如下

XML布局代码

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.tomes.paint.MainActivity" >

<ImageView
 android:id="@ id/iv_drawingBoard"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:src="@drawable/bg"/>

</RelativeLayout>

Java代码

public void init() {
Bitmap bitmap = BitmapFactory.decodeResource(getResources(),
  R.drawable.bg);
copyBitmap = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), bitmap.getConfig());
paint = new Paint();
canvas = new Canvas(copyBitmap);
Matrix matrix=new Matrix();
canvas.drawBitmap(bitmap, matrix, paint);

imageView = (ImageView) findViewById(R.id.iv_drawingBoard);

imageView.setImageBitmap(copyBitmap);

imageView.setOnTouchListener(new OnTouchListener() {

@SuppressLint("ClickableViewAccessibility")
 @Override
 public boolean onTouch(View v, MotionEvent event) {
  int action = event.getAction();
  switch (action) {
  case MotionEvent.ACTION_DOWN:
    startX=event.getX();
    startY=event.getY();
   break;
  case MotionEvent.ACTION_MOVE:
   float currentX=event.getX();
   float currentY=event.getY();
   canvas.drawLine(startX, startY, currentX, currentY, paint);
   imageView.setImageBitmap(copyBitmap);
   startX=currentX;
   startY=currentY;

break;
  case MotionEvent.ACTION_UP:

break;

}
  return true;
 }
});

}

源码下载：点击这里

总结