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
------解决思路----------------------
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;
}
}