android保存Canvas

JPF1024 2015-06-15 11:53:31
MyView.java:



package com.jikexueyuan.drawingboard.app;



import android.content.Context;

import android.graphics.*;

import android.media.MediaScannerConnection;

import android.net.Uri;

import android.os.Environment;

import android.util.AttributeSet;

import android.util.Log;

import android.view.MotionEvent;

import android.view.SurfaceHolder;

import android.view.SurfaceView;

import android.view.View;

import android.widget.Toast;



import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.text.SimpleDateFormat;

import java.util.Date;



/**

 * Created by puruidong on 6/14/15.

 */

public class MyView extends SurfaceView implements SurfaceHolder.Callback, View.OnTouchListener {





    private Paint p = new Paint();

    private Path path = new Path();

    private  Bitmap bi = Bitmap.createBitmap(400, 800, Bitmap.Config.ARGB_8888);







    public MyView(Context context, AttributeSet attrs) {

        super(context, attrs);

        getHolder().addCallback(this);

        p.setColor(Color.RED);

        p.setTextSize(40);

        p.setStrokeWidth(5);

        p.setAntiAlias(true);

        p.setFlags(Paint.ANTI_ALIAS_FLAG);

        p.setStyle(Paint.Style.STROKE);

        setOnTouchListener(this);

    }





    private void draw() {

        Canvas canvas = getHolder().lockCanvas();

        canvas.drawColor(Color.WHITE);

        canvas.drawPath(path, p);

        canvas.setBitmap(bi);

        getHolder().unlockCanvasAndPost(canvas);

        canvas.setBitmap(bi);

    }



    private String getTime() {

        return new SimpleDateFormat("HHmmssSSS").format(new Date(System.currentTimeMillis()));

    }





    //保存圖片.

    public void saveCanvas(View v) {

        Canvas c = new Canvas(bi);

        c.drawColor(Color.WHITE);

        this.draw(c);

        FileOutputStream fos = null;

        try {

            String fileName = getTime();

            String filePath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM) + fileName + ".png";

            fos = new FileOutputStream(

                    new File(filePath));

            bi.compress(Bitmap.CompressFormat.PNG, 100, fos);

            MediaScannerConnection.scanFile(getContext(), new String[]

                            {filePath}, null,

                    new MediaScannerConnection.OnScanCompletedListener() {

                        @Override

                        public void onScanCompleted(String path, Uri uri) {

                            Log.v("MediaScanWork", "file " + path

                                    + " was scanned seccessfully: " + uri);

                        }

                    });

            Toast.makeText(getContext(), "保存成功,文件名:" + fileName + ".png", Toast.LENGTH_LONG).show();

            clear();

        } catch (IOException e) {

            e.printStackTrace();

        }

    }



    public void clear() {

        path.reset();

        draw();

    }





    @Override

    public void surfaceCreated(SurfaceHolder holder) {

        draw();

    }



    @Override

    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {



    }



    @Override

    public void surfaceDestroyed(SurfaceHolder holder) {



    }



    @Override

    public boolean onTouch(View v, MotionEvent event) {

        switch (event.getAction()) {

            case MotionEvent.ACTION_DOWN:



                path.moveTo(event.getX(), event.getY());

                draw();

                break;

            case MotionEvent.ACTION_UP:

                path.lineTo(event.getX(), event.getY());

                draw();

                break;

        }

        return true;

    }

}


MainActivity.java:





package com.jikexueyuan.drawingboard.app;



import android.app.Activity;

import android.os.Bundle;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.widget.Button;



/**

 * HuaBu-Write,Save

 *

 * @author puruidong

 * @version 2015.6.14

 *

 */

public class MainActivity extends Activity {





    private Button btn;

    private Button save;

    private MyView view;





    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        btn = (Button) findViewById(R.id.btn);

        save = (Button) findViewById(R.id.save);

        view = (MyView) findViewById(R.id.draw);

        btn.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                view.clear();

            }

        });

        save.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                view.saveCanvas(view);

            }

        });





    }





}


activity_main.xml:




<LinearLayout 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:orientation="vertical"

              tools:context=".MainActivity"

        >





    <com.jikexueyuan.drawingboard.app.MyView

            android:id="@+id/draw"

            android:layout_width="fill_parent"

            android:layout_height="0dp"

            android:layout_weight="1"

            />



    <LinearLayout

            android:layout_width="fill_parent"

            android:layout_height="wrap_content"

            android:orientation="horizontal"



            >

        <Button

                android:id="@+id/btn"

                android:layout_weight="1"

                android:layout_width="wrap_content"

                android:layout_height="wrap_content"

                android:text="清理"

                />



        <Button

                android:id="@+id/save"

                android:layout_weight="1"

                android:layout_width="wrap_content"

                android:layout_height="wrap_content"

                android:text="保存"

                />



    </LinearLayout>

 

</LinearLayout>


保存的是黑色，没有图像，希望可以告诉我一下要改哪里,谢谢
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JPF1024 2015-06-16
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引用 4 楼 u014165119 的回复:
[quote=引用 3 楼 dcxy0 的回复:] [quote=引用 2 楼 u014165119 的回复:] SurfaceView不能截图
那怎么才可以操作呢？把SurfaceView替换成什么就可以了？[/quote] SurfaceView是不能截图的，不过看了你代码发现不是这个原因造成的保存不了图片，是canvas.setBitmap()的位置不对，画完才设置Bitmap上去，肯定画不出来，所以我先把draw方法改成了这样： 

private void draw() {
        Canvas canvas = getHolder().lockCanvas();
        canvas.setBitmap(bi);
        canvas.drawColor(Color.WHITE);
        canvas.drawPath(path, p);
        getHolder().unlockCanvasAndPost(canvas);
    }
这样虽然能够保存画出的图片，但是看不到SurfaceView了，所以我又改了一下，并优化了一下MyView.java的代码： 

import android.content.Context;
import android.graphics.*;
import android.media.MediaScannerConnection;
import android.net.Uri;
import android.os.Environment;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Toast;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * Created by puruidong on 6/14/15.
 */
public class MyView extends SurfaceView implements SurfaceHolder.Callback,
		View.OnTouchListener {

	private SurfaceHolder holder = null;
	private Canvas canvas = null;
	private Canvas canvasTemp = null;
	private Bitmap bi = null;
	private Paint p = new Paint();
	private Path path = new Path();

	public MyView(Context context, AttributeSet attrs) {
		super(context, attrs);
		holder = getHolder();
		holder.addCallback(this);
		p.setColor(Color.RED);
		p.setTextSize(40);
		p.setStrokeWidth(5);
		p.setAntiAlias(true);
		p.setFlags(Paint.ANTI_ALIAS_FLAG);
		p.setStyle(Paint.Style.STROKE);
		setOnTouchListener(this);
	}

	private void draw() {
		try {
			canvas = holder.lockCanvas();
			if (holder != null) {
				canvasTemp.drawColor(Color.WHITE);
				canvasTemp.drawPath(path, p);
				canvas.drawBitmap(bi, 0, 0, null);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (holder != null) {
				holder.unlockCanvasAndPost(canvas);
			}
		}
	}

	private String getTime() {
		return new SimpleDateFormat("HHmmssSSS").format(new Date(System
				.currentTimeMillis()));
	}

	// 保存圖片.
	// 这里参数没有用到，可以去掉
	public void saveCanvas(View v) {
		FileOutputStream fos = null;
		try {
			String fileName = getTime();
			String filePath = Environment
					.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM)
					+ fileName + ".png";
			fos = new FileOutputStream(new File(filePath));
			bi.compress(Bitmap.CompressFormat.PNG, 100, fos);
			MediaScannerConnection.scanFile(getContext(),
					new String[] { filePath }, null,
					new MediaScannerConnection.OnScanCompletedListener() {
						@Override
						public void onScanCompleted(String path, Uri uri) {
							Log.v("MediaScanWork", "file " + path
									+ " was scanned seccessfully: " + uri);
						}
					});
			Toast.makeText(getContext(), "保存成功,文件名:" + fileName + ".png",
					Toast.LENGTH_LONG).show();
			clear();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	public void clear() {
		path.reset();
		draw();
	}

	@Override
	public void surfaceCreated(SurfaceHolder holder) {
		bi = Bitmap.createBitmap(getWidth(), getHeight(),
				Bitmap.Config.ARGB_8888);
		canvasTemp = new Canvas(bi);
		draw();
	}

	@Override
	public void surfaceChanged(SurfaceHolder holder, int format, int width,
			int height) {

	}

	@Override
	public void surfaceDestroyed(SurfaceHolder holder) {

	}

	@Override
	public boolean onTouch(View v, MotionEvent event) {
		switch (event.getAction()) {
		case MotionEvent.ACTION_DOWN:

			path.moveTo(event.getX(), event.getY());
			draw();
			break;
		case MotionEvent.ACTION_MOVE: // 画出每次移动的轨迹
		case MotionEvent.ACTION_UP:
			path.lineTo(event.getX(), event.getY());
			draw();
			break;
		}
		return true;
	}
}
[/quote] 我之前就设置过setbitmap(),也是设置了就看不到SurfaceView了，就是不知道怎么解决。 谢谢了。
StoneHui_ 2015-06-16
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引用 3 楼 dcxy0 的回复:
[quote=引用 2 楼 u014165119 的回复:] SurfaceView不能截图
那怎么才可以操作呢？把SurfaceView替换成什么就可以了？[/quote] SurfaceView是不能截图的，不过看了你代码发现不是这个原因造成的保存不了图片，是canvas.setBitmap()的位置不对，画完才设置Bitmap上去，肯定画不出来，所以我先把draw方法改成了这样： 

private void draw() {
        Canvas canvas = getHolder().lockCanvas();
        canvas.setBitmap(bi);
        canvas.drawColor(Color.WHITE);
        canvas.drawPath(path, p);
        getHolder().unlockCanvasAndPost(canvas);
    }
这样虽然能够保存画出的图片，但是看不到SurfaceView了，所以我又改了一下，并优化了一下MyView.java的代码： 

import android.content.Context;
import android.graphics.*;
import android.media.MediaScannerConnection;
import android.net.Uri;
import android.os.Environment;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Toast;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * Created by puruidong on 6/14/15.
 */
public class MyView extends SurfaceView implements SurfaceHolder.Callback,
		View.OnTouchListener {

	private SurfaceHolder holder = null;
	private Canvas canvas = null;
	private Canvas canvasTemp = null;
	private Bitmap bi = null;
	private Paint p = new Paint();
	private Path path = new Path();

	public MyView(Context context, AttributeSet attrs) {
		super(context, attrs);
		holder = getHolder();
		holder.addCallback(this);
		p.setColor(Color.RED);
		p.setTextSize(40);
		p.setStrokeWidth(5);
		p.setAntiAlias(true);
		p.setFlags(Paint.ANTI_ALIAS_FLAG);
		p.setStyle(Paint.Style.STROKE);
		setOnTouchListener(this);
	}

	private void draw() {
		try {
			canvas = holder.lockCanvas();
			if (holder != null) {
				canvasTemp.drawColor(Color.WHITE);
				canvasTemp.drawPath(path, p);
				canvas.drawBitmap(bi, 0, 0, null);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (holder != null) {
				holder.unlockCanvasAndPost(canvas);
			}
		}
	}

	private String getTime() {
		return new SimpleDateFormat("HHmmssSSS").format(new Date(System
				.currentTimeMillis()));
	}

	// 保存圖片.
	// 这里参数没有用到，可以去掉
	public void saveCanvas(View v) {
		FileOutputStream fos = null;
		try {
			String fileName = getTime();
			String filePath = Environment
					.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM)
					+ fileName + ".png";
			fos = new FileOutputStream(new File(filePath));
			bi.compress(Bitmap.CompressFormat.PNG, 100, fos);
			MediaScannerConnection.scanFile(getContext(),
					new String[] { filePath }, null,
					new MediaScannerConnection.OnScanCompletedListener() {
						@Override
						public void onScanCompleted(String path, Uri uri) {
							Log.v("MediaScanWork", "file " + path
									+ " was scanned seccessfully: " + uri);
						}
					});
			Toast.makeText(getContext(), "保存成功,文件名:" + fileName + ".png",
					Toast.LENGTH_LONG).show();
			clear();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	public void clear() {
		path.reset();
		draw();
	}

	@Override
	public void surfaceCreated(SurfaceHolder holder) {
		bi = Bitmap.createBitmap(getWidth(), getHeight(),
				Bitmap.Config.ARGB_8888);
		canvasTemp = new Canvas(bi);
		draw();
	}

	@Override
	public void surfaceChanged(SurfaceHolder holder, int format, int width,
			int height) {

	}

	@Override
	public void surfaceDestroyed(SurfaceHolder holder) {

	}

	@Override
	public boolean onTouch(View v, MotionEvent event) {
		switch (event.getAction()) {
		case MotionEvent.ACTION_DOWN:

			path.moveTo(event.getX(), event.getY());
			draw();
			break;
		case MotionEvent.ACTION_MOVE: // 画出每次移动的轨迹
		case MotionEvent.ACTION_UP:
			path.lineTo(event.getX(), event.getY());
			draw();
			break;
		}
		return true;
	}
}
JPF1024 2015-06-16
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引用 2 楼 u014165119 的回复:
SurfaceView不能截图
那怎么才可以操作呢？把SurfaceView替换成什么就可以了？
StoneHui_ 2015-06-16
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SurfaceView不能截图
JPF1024 2015-06-15
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保存bitmap已经实现了.只是保存的是黑色的，不知道怎么设置了，等大神，谢谢
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