我有一个应用程序，我希望能够捕获截图。布局的背景是surfaceView，它显示后置摄像头的视频。以下代码可以截取屏幕截图，但surfaceView的内容保存为黑色。这是代码：
btn.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
Random num = new Random();
int nu=num.nextInt(1000);
Bitmap bmp;
CamView.setDrawingCacheEnabled(true);
CamView.buildDrawingCache(true);
Bitmap bmp2 = Bitmap.createBitmap(CamView.getDrawingCache()); //Screenshot of the layout
CamView.setDrawingCacheEnabled(false);
SurView.setDrawingCacheEnabled(true);
SurView.buildDrawingCache(true);
Bitmap bmp1 = Bitmap.createBitmap(SurView.getDrawingCache()); //Screenshot of the surfaceView
SurView.setDrawingCacheEnabled(false);
Bitmap bmOverlay = Bitmap.createBitmap(bmp1.getWidth(), bmp1.getHeight(),bmp1.getConfig());
Canvas canvas = new Canvas(bmOverlay); //Overlaying the 2 bitmaps
canvas.drawBitmap(bmp1, 0,0, null);
canvas.drawBitmap(bmp2, 0,0, null);
bmp=bmOverlay;
//saving the file
ByteArrayOutputStream bos = new ByteArrayOutputStream();
bmp.compress(CompressFormat.JPEG, 100, bos);
byte[] bitmapdata = bos.toByteArray();
ByteArrayInputStream fis = new ByteArrayInputStream(bitmapdata);
String picId=String.valueOf(nu);
String myfile="Ghost"+picId+".jpeg";
File dir_image = new File(Environment.getExternalStorageDirectory()+
File.separator+"Ultimate Entity Detector");
dir_image.mkdirs();
try {
File tmpFile = new File(dir_image,myfile);
FileOutputStream fos = new FileOutputStream(tmpFile);
byte[] buf = new byte[1024];
int len;
while ((len = fis.read(buf)) > 0) {
fos.write(buf, 0, len);
}
fis.close();
fos.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
});
我更新了代码。现在我创建2个位图，1个用于布局xml，1个用于surfaceView，然后我将它们叠加到单个位图中。但是surfaceView位图仍然是黑色的
答案 0 :(得分：11)
我终于解决了这个问题。下面我给一些想要知道如何截取布局截图，无意图的相机图片，SurfaceView内容的截图（点击）以及将屏幕截图保存在文件夹中的人提供一些代码：
public class Cam_View extends Activity implements SurfaceHolder.Callback {
protected static final int CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE = 0;
private SurfaceView SurView;
private SurfaceHolder camHolder;
private boolean previewRunning;
final Context context = this;
public static Camera camera = null;
private RelativeLayout CamView;
private Bitmap inputBMP = null, bmp, bmp1;
private ImageView mImage;
@SuppressWarnings("deprecation")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.camera);
CamView = (RelativeLayout) findViewById(R.id.camview);//RELATIVELAYOUT OR
//ANY LAYOUT OF YOUR XML
SurView = (SurfaceView)findViewById(R.id.sview);//SURFACEVIEW FOR THE PREVIEW
//OF THE CAMERA FEED
camHolder = SurView.getHolder(); //NEEDED FOR THE PREVIEW
camHolder.addCallback(this); //NEEDED FOR THE PREVIEW
camHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);//NEEDED FOR THE PREVIEW
camera_image = (ImageView) findViewById(R.id.camera_image);//NEEDED FOR THE PREVIEW
Button btn = (Button) findViewById(R.id.button1); //THE BUTTON FOR TAKING PICTURE
btn.setOnClickListener(new OnClickListener() { //THE BUTTON CODE
public void onClick(View v) {
camera.takePicture(null, null, mPicture);//TAKING THE PICTURE
//THE mPicture IS CALLED
//WHICH IS THE LAST METHOD(SEE BELOW)
}
});
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,//NEEDED FOR THE PREVIEW
int height) {
if(previewRunning) {
camera.stopPreview();
}
Camera.Parameters camParams = camera.getParameters();
Camera.Size size = camParams.getSupportedPreviewSizes().get(0);
camParams.setPreviewSize(size.width, size.height);
camera.setParameters(camParams);
try {
camera.setPreviewDisplay(holder);
camera.startPreview();
previewRunning=true;
} catch(IOException e) {
e.printStackTrace();
}
}
public void surfaceCreated(SurfaceHolder holder) { //NEEDED FOR THE PREVIEW
try {
camera=Camera.open();
} catch(Exception e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(),"Error",Toast.LENGTH_LONG).show();
finish();
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) { //NEEDED FOR THE PREVIEW
camera.stopPreview();
camera.release();
camera=null;
}
public void TakeScreenshot(){ //THIS METHOD TAKES A SCREENSHOT AND SAVES IT AS .jpg
Random num = new Random();
int nu=num.nextInt(1000); //PRODUCING A RANDOM NUMBER FOR FILE NAME
CamView.setDrawingCacheEnabled(true); //CamView OR THE NAME OF YOUR LAYOUR
CamView.buildDrawingCache(true);
Bitmap bmp = Bitmap.createBitmap(CamView.getDrawingCache());
CamView.setDrawingCacheEnabled(false); // clear drawing cache
ByteArrayOutputStream bos = new ByteArrayOutputStream();
bmp.compress(CompressFormat.JPEG, 100, bos);
byte[] bitmapdata = bos.toByteArray();
ByteArrayInputStream fis = new ByteArrayInputStream(bitmapdata);
String picId=String.valueOf(nu);
String myfile="Ghost"+picId+".jpeg";
File dir_image = new File(Environment.getExternalStorageDirectory()+//<---
File.separator+"Ultimate Entity Detector"); //<---
dir_image.mkdirs(); //<---
//^IN THESE 3 LINES YOU SET THE FOLDER PATH/NAME . HERE I CHOOSE TO SAVE
//THE FILE IN THE SD CARD IN THE FOLDER "Ultimate Entity Detector"
try {
File tmpFile = new File(dir_image,myfile);
FileOutputStream fos = new FileOutputStream(tmpFile);
byte[] buf = new byte[1024];
int len;
while ((len = fis.read(buf)) > 0) {
fos.write(buf, 0, len);
}
fis.close();
fos.close();
Toast.makeText(getApplicationContext(),
"The file is saved at :SD/Ultimate Entity Detector",Toast.LENGTH_LONG).show();
bmp1 = null;
camera_image.setImageBitmap(bmp1); //RESETING THE PREVIEW
camera.startPreview(); //RESETING THE PREVIEW
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private PictureCallback mPicture = new PictureCallback() { //THIS METHOD AND THE METHOD BELOW
//CONVERT THE CAPTURED IMAGE IN A JPG FILE AND SAVE IT
@Override
public void onPictureTaken(byte[] data, Camera camera) {
File dir_image2 = new File(Environment.getExternalStorageDirectory()+
File.separator+"Ultimate Entity Detector");
dir_image2.mkdirs(); //AGAIN CHOOSING FOLDER FOR THE PICTURE(WHICH IS LIKE A SURFACEVIEW
//SCREENSHOT)
File tmpFile = new File(dir_image2,"TempGhost.jpg"); //MAKING A FILE IN THE PATH
//dir_image2(SEE RIGHT ABOVE) AND NAMING IT "TempGhost.jpg" OR ANYTHING ELSE
try { //SAVING
FileOutputStream fos = new FileOutputStream(tmpFile);
fos.write(data);
fos.close();
//grabImage();
} catch (FileNotFoundException e) {
Toast.makeText(getApplicationContext(),"Error",Toast.LENGTH_LONG).show();
} catch (IOException e) {
Toast.makeText(getApplicationContext(),"Error",Toast.LENGTH_LONG).show();
}
String path = (Environment.getExternalStorageDirectory()+
File.separator+"Ultimate EntityDetector"+
File.separator+"TempGhost.jpg");//<---
BitmapFactory.Options options = new BitmapFactory.Options();//<---
options.inPreferredConfig = Bitmap.Config.ARGB_8888;//<---
bmp1 = BitmapFactory.decodeFile(path, options);//<--- *********(SEE BELOW)
//THE LINES ABOVE READ THE FILE WE SAVED BEFORE AND CONVERT IT INTO A BitMap
camera_image.setImageBitmap(bmp1); //SETTING THE BitMap AS IMAGE IN AN IMAGEVIEW(SOMETHING
//LIKE A BACKGROUNG FOR THE LAYOUT)
tmpFile.delete();
TakeScreenshot();//CALLING THIS METHOD TO TAKE A SCREENSHOT
//********* THAT LINE MIGHT CAUSE A CRASH ON SOME PHONES (LIKE XPERIA T)<----(SEE HERE)
//IF THAT HAPPENDS USE THE LINE "bmp1 =decodeFile(tmpFile);" WITH THE METHOD BELOW
}
};
public Bitmap decodeFile(File f) { //FUNCTION BY Arshad Parwez
Bitmap b = null;
try {
// Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
FileInputStream fis = new FileInputStream(f);
BitmapFactory.decodeStream(fis, null, o);
fis.close();
int IMAGE_MAX_SIZE = 1000;
int scale = 1;
if (o.outHeight > IMAGE_MAX_SIZE || o.outWidth > IMAGE_MAX_SIZE) {
scale = (int) Math.pow(
2,
(int) Math.round(Math.log(IMAGE_MAX_SIZE
/ (double) Math.max(o.outHeight, o.outWidth))
/ Math.log(0.5)));
}
// Decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
fis = new FileInputStream(f);
b = BitmapFactory.decodeStream(fis, null, o2);
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
return b;
}
}
如果你想拍一个简单的截图（不需要摄像头），你可以单独使用TakeScreenshot方法。
如果你想直接从surfaceview获取一个surfaceView的截图，请使用mPicture，将你捕获的图片设置为背景幕，然后调用TakeScreenshot来截取屏幕截图。（如上所示）
如果您想使用相机拍摄照片而不打算使用其他相机应用程序，请使用带有mPicture的takePicture和上面代码中的surfaceView内容。
如果按“原样”使用，之前的代码所做的是截取布局内容（按钮，图像视图等）的截图，并将相机中的图像设置为背景。
下面我还提供了上一代码的基本布局xml：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/camview">
<SurfaceView
android:id="@+id/sview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true" />
<ImageView
android:id="@+id/camera_image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:contentDescription="@string/app_name" />
<Button
android:id="@+id/button1"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true" />
</RelativeLayout>
别忘了导入需要导入的内容
答案 1 :(得分：3)
根据Android Framework工程师的评论（https://groups.google.com/forum/#!topic/android-developers/jYjvm7ItpXQ），SurfaceView不会被视为普通视图：
表面视图实际上是在您的窗户后面，并打了一个洞 你可以看到它的窗口。因此，你可以把它放在上面 你的窗口，但窗口中的任何内容都不会出现在它后面。
由于它是“背后”应用程序窗口，因此窗口视图的绘图不会包含它。我想，唯一的办法就是在SurfaceView类中提供一个方法，将自己的内容绘制到提供的Canvas / Bitmap中。