view實現塗鴉功能

Java代碼

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
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.graphics.Bitmap.CompressFormat;
import android.os.Environment;
import android.view.MotionEvent;
import android.view.View;
/**
* View實現塗鴉、撤銷以及重做功能
*/
public class TuyaView extends View {
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;// 畫布的畫筆
private Paint mPaint;// 真實的畫筆
private float mX, mY;// 臨時點座標
private static final float TOUCH_TOLERANCE = 4;
// 保存Path路徑的集合,用List集合來模擬棧
private static List<DrawPath> savePath;
// 記錄Path路徑的對象
private DrawPath dp;
private int screenWidth, screenHeight;
private class DrawPath {
public Path path;// 路徑
public Paint paint;// 畫筆
}
public TuyaView(Context context, int w, int h) {
super(context);
screenWidth = w;
screenHeight = h;
mBitmap = Bitmap.createBitmap(screenWidth, screenHeight, Bitmap.Config.ARGB_8888);
// 保存一次一次繪製出來的圖形
mCanvas = new Canvas(mBitmap);
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);// 設置外邊緣
mPaint.setStrokeCap(Paint.Cap.ROUND);// 形狀
mPaint.setStrokeWidth(5);// 畫筆寬度
savePath = new ArrayList<DrawPath>();
}
@Override
public void onDraw(Canvas canvas) {
canvas.drawColor(0xFFAAAAAA);
// 將前面已經畫過得顯示出來
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
if (mPath != null) {
// 實時的顯示
canvas.drawPath(mPath, mPaint);
}
}
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(mY - y);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
// 從x1,y1到x2,y2畫一條貝塞爾曲線，更平滑(直接用mPath.lineTo也是可以的)
mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
}
}
private void touch_up() {
mPath.lineTo(mX, mY);
mCanvas.drawPath(mPath, mPaint);
//將一條完整的路徑保存下來(相當於入棧操作)
savePath.add(dp);
mPath = null;// 重新置空
}
/**
* 撤銷的核心思想就是將畫布清空，
* 將保存下來的Path路徑最後一個移除掉，
* 重新將路徑畫在畫布上面。
*/
public void undo() {
if (savePath != null && savePath.size() > 0) {
savePath.remove(savePath.size() - 1);
redrawOnBitmap();
}
}
/**
* 重做
*/
public void redo(){
if (savePath != null && savePath.size() > 0) {
savePath.clear();
redrawOnBitmap();
}
}
private void redrawOnBitmap(){
mBitmap = Bitmap.createBitmap(screenWidth, screenHeight,
Bitmap.Config.ARGB_8888);
mCanvas.setBitmap(mBitmap);// 重新設置畫布，相當於清空畫布
Iterator<DrawPath> iter = savePath.iterator();
while (iter.hasNext()) {
DrawPath drawPath = iter.next();
mCanvas.drawPath(drawPath.path, drawPath.paint);
}
invalidate();// 刷新
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
// 每次down下去重新new一個Path
mPath = new Path();
//每一次記錄的路徑對象是不一樣的
dp = new DrawPath();
dp.path = mPath;
dp.paint = mPaint;
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;
}
public void saveToSDCard(){
String fileUrl = Environment.getExternalStorageDirectory()
.toString() + "/android/data/test.png";
try {
FileOutputStream fos = new FileOutputStream(new File(fileUrl));
mBitmap.compress(CompressFormat.PNG, 100, fos);
fos.flush();
fos.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
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.graphics.Bitmap.CompressFormat;
import android.os.Environment;
import android.view.MotionEvent;
import android.view.View;

/**
 * View實現塗鴉、撤銷以及重做功能
 */

public class TuyaView extends View {

	private Bitmap mBitmap;
	private Canvas mCanvas;
	private Path mPath;
	private Paint mBitmapPaint;// 畫布的畫筆
	private Paint mPaint;// 真實的畫筆
	private float mX, mY;// 臨時點座標
	private static final float TOUCH_TOLERANCE = 4;
	
	// 保存Path路徑的集合,用List集合來模擬棧
	private static List<DrawPath> savePath;
	// 記錄Path路徑的對象
	private DrawPath dp;

	private int screenWidth, screenHeight;

	private class DrawPath {
		public Path path;// 路徑
		public Paint paint;// 畫筆
	}

	public TuyaView(Context context, int w, int h) {
		super(context);
		screenWidth = w;
		screenHeight = h;

		mBitmap = Bitmap.createBitmap(screenWidth, screenHeight, Bitmap.Config.ARGB_8888);
		// 保存一次一次繪製出來的圖形
		mCanvas = new Canvas(mBitmap);

		mBitmapPaint = new Paint(Paint.DITHER_FLAG);
		mPaint = new Paint();
		mPaint.setAntiAlias(true);
		mPaint.setStyle(Paint.Style.STROKE);
		mPaint.setStrokeJoin(Paint.Join.ROUND);// 設置外邊緣
		mPaint.setStrokeCap(Paint.Cap.ROUND);// 形狀
		mPaint.setStrokeWidth(5);// 畫筆寬度

		savePath = new ArrayList<DrawPath>();
	}

	@Override
	public void onDraw(Canvas canvas) {
		canvas.drawColor(0xFFAAAAAA);
		// 將前面已經畫過得顯示出來
		canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
		if (mPath != null) {
			// 實時的顯示
			canvas.drawPath(mPath, mPaint);
		}
	}

	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(mY - y);
		if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
			// 從x1,y1到x2,y2畫一條貝塞爾曲線，更平滑(直接用mPath.lineTo也是可以的)
			mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
			mX = x;
			mY = y;
		}
	}

	private void touch_up() {
		mPath.lineTo(mX, mY);
		mCanvas.drawPath(mPath, mPaint);
		//將一條完整的路徑保存下來(相當於入棧操作)
		savePath.add(dp);
		mPath = null;// 重新置空
	}
	/**
	 * 撤銷的核心思想就是將畫布清空，
	 * 將保存下來的Path路徑最後一個移除掉，
	 * 重新將路徑畫在畫布上面。
	 */
	public void undo() {
		if (savePath != null && savePath.size() > 0) {
			savePath.remove(savePath.size() - 1);
			redrawOnBitmap();
		}
	}
	/**
	 * 重做
	 */
	public void redo(){
		if (savePath != null && savePath.size() > 0) {
			savePath.clear();
			redrawOnBitmap();
		}
	}
	
	private void redrawOnBitmap(){
		mBitmap = Bitmap.createBitmap(screenWidth, screenHeight,
				Bitmap.Config.ARGB_8888);
		mCanvas.setBitmap(mBitmap);// 重新設置畫布，相當於清空畫布 
		Iterator<DrawPath> iter = savePath.iterator();
		while (iter.hasNext()) {
			DrawPath drawPath = iter.next();
			mCanvas.drawPath(drawPath.path, drawPath.paint);
		}
		invalidate();// 刷新
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {
		float x = event.getX();
		float y = event.getY();

		switch (event.getAction()) {
		case MotionEvent.ACTION_DOWN:
			// 每次down下去重新new一個Path
			mPath = new Path();
			//每一次記錄的路徑對象是不一樣的
			dp = new DrawPath();
			dp.path = mPath;
			dp.paint = mPaint;
			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;
	}

	public void saveToSDCard(){
		String fileUrl = Environment.getExternalStorageDirectory()
				.toString() + "/android/data/test.png";
		try {
			FileOutputStream fos = new FileOutputStream(new File(fileUrl));
			mBitmap.compress(CompressFormat.PNG, 100, fos);
			fos.flush();
			fos.close();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}

Java代碼

import android.app.Activity;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.KeyEvent;
public class TuyaActivity extends Activity {
private TuyaView tuyaView = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
DisplayMetrics dm = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
tuyaView = new TuyaView(this, dm.widthPixels, dm.heightPixels);
setContentView(tuyaView);
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {// 返回鍵
tuyaView.undo();
return true;
}else if(keyCode == KeyEvent.KEYCODE_MENU){//MENU
tuyaView.redo();
return true;
}
return super.onKeyDown(keyCode, event);
}
}

import android.app.Activity;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.KeyEvent;

public class TuyaActivity extends Activity {

	private TuyaView tuyaView = null;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);

		DisplayMetrics dm = new DisplayMetrics();
		getWindowManager().getDefaultDisplay().getMetrics(dm);

		tuyaView = new TuyaView(this, dm.widthPixels, dm.heightPixels);
		setContentView(tuyaView);
	}

	@Override
	public boolean onKeyDown(int keyCode, KeyEvent event) {
		if (keyCode == KeyEvent.KEYCODE_BACK) {// 返回鍵
			tuyaView.undo();
			return true;
		}else if(keyCode == KeyEvent.KEYCODE_MENU){//MENU
			tuyaView.redo();
			return true;
		}
		return super.onKeyDown(keyCode, event);
	}

}

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