Android指描画(二)
2303 ワード
package cn.c;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.Display;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
public class MainActivity extends Activity{
private ImageView mImageView;
private Bitmap mBitmap;
private Paint mPaint;
private Canvas mCanvas;
float downX=0;
float downY=0;
float upX=0;
float upY=0;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mImageView=(ImageView) findViewById(R.id.imageView);
Display display=getWindowManager().getDefaultDisplay();
int w=display.getWidth();
int h=display.getHeight();
mBitmap=Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas=new Canvas(mBitmap);
mPaint=new Paint();
mPaint.setColor(Color.RED);
mImageView.setImageBitmap(mBitmap);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
int action = event.getAction();
switch (action) {
case MotionEvent.ACTION_DOWN:
downX=event.getX();
downY=event.getY();
break;
case MotionEvent.ACTION_MOVE:
upX=event.getX();
upY=event.getY();
mCanvas.drawLine(downX, downY, upX, upY, mPaint);
mImageView.invalidate();
downX=upX;
downY=upY;
break;
case MotionEvent.ACTION_UP:
upX=event.getX();
upY=event.getY();
mCanvas.drawLine(downX, downY, upX, upY, mPaint);
mImageView.invalidate();
break;
case MotionEvent.ACTION_CANCEL:
break;
default:
break;
}
return true;
}
}