blocks|key|99986|text|我没有一个完整的工作示例，但我可以给你我的一个项目的片段，在这个项目中，我也将相机预览放在比全屏更小的视图中。我只是想传达一下我的想法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|99987|你需要的是一个可以保存相机预览的FrameLayout|99988|<?xml+version="1.0"+encoding="utf-8"?>
<RelativeLayout+xmlns:android="http://schemas.android.com/apk/res/android"
++++android:id="@%2Bid/absoluteLayout1"
++++android:layout_width="fill_parent"
++++android:layout_height="fill_parent"
++++android:background="@android:color/transparent"
++++android:orientation="vertical"+>

++++<FrameLayout
++++++++android:id="@%2Bid/camera_preview"
++++++++android:layout_width="200dp"
++++++++android:layout_height="200dip"+>
++++</FrameLayout>

</RelativeLayout>|code-block|syntax|javascript|99989|现在我们需要一个PreviewListener，它也是一个视图|99990|import+java.io.IOException;

import+android.content.Context;
import+android.hardware.Camera;
import+android.util.Log;
import+android.view.SurfaceHolder;
import+android.view.SurfaceView;

/**+A+basic+Camera+preview+class+*/
public+class+CameraPreviewListener+extends+SurfaceView+implements+SurfaceHolder.Callback+{
++++private+SurfaceHolder+mHolder;
++++private+Camera+mCamera;

++++public+CameraPreviewListener(Context+context,+Camera+camera)+{
++++++++super(context);
++++++++mCamera+=+camera;

++++++++//+Install+a+SurfaceHolder.Callback+so+we+get+notified+when+the
++++++++//+underlying+surface+is+created+and+destroyed.
++++++++mHolder+=+getHolder();
++++++++mHolder.addCallback(this);

++++++++//+deprecated+setting,+but+required+on+Android+versions+prior+to+3.0
++++++++mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
++++}

++++public+void+surfaceCreated(SurfaceHolder+holder)+{
++++++++//+The+Surface+has+been+created,+now+tell+the+camera+where+to+draw+the+preview.
++++++++mCamera.setPreviewDisplay(holder);
++++++++mCamera.startPreview();
++++}

++++public+void+surfaceDestroyed(SurfaceHolder+holder)+{
++++++++//+Take+care+of+releasing+the+Camera+preview+in+your+activity.
++++++++Log.d("camera",+"surfaceDestroyed");
++++++++if(holder.equals(mHolder)){
++++++++++++holder.removeCallback(this);++++++++++++
++++++++}else{
++++++++++++holder.removeCallback(this);
++++++++++++mHolder.removeCallback(this);
++++++++}
++++}

++++public+void+surfaceChanged(SurfaceHolder+holder,+int+format,+int+w,+int+h)+{
++++++++//+If+your+preview+can+change+or+rotate,+take+care+of+those+events+here.
++++++++//+Make+sure+to+stop+the+preview+before+resizing+or+reformatting+it.

++++++++if+(mHolder.getSurface()+==+null){
++++++++++//+preview+surface+does+not+exist
++++++++++return;
++++++++}

++++++++//+stop+preview+before+making+changes
++++++++try+{
++++++++++++mCamera.stopPreview();

++++++++}+catch+(Exception+e){
++++++++++++e.printStackTrace();
++++++++++//+ignore:+tried+to+stop+a+non-existent+preview
++++++++}

++++++++//+set+preview+size+and+make+any+resize,+rotate+or
++++++++//+reformatting+changes+here

++++++++//+start+preview+with+new+settings
++++++++try+{
++++++++++++mCamera.setPreviewDisplay(mHolder);
++++++++++++mCamera.startPreview();

++++++++}+catch+(Exception+e){
++++++++++++Log.d("camera",+"Error+starting+camera+preview:+"+%2B+e.getMessage());
++++++++}
++++}

++++public+void+removeCallback(){
++++++++mHolder+=+getHolder();
++++++++mHolder.removeCallback(this);
++++}
}|99991|最后，你需要在你的活动中组装所有的东西|99992|import+android.hardware.Camera;

Camera+mCamera+=++=+getCameraInstance();
CameraPreviewListener+cpl+=+new+CameraPreviewListener(this,+mCamera);
FrameLayout+preview+=+(FrameLayout)+findViewById(R.id.camera_preview);
preview.addView(cpl);|99993|要获取摄像头，您可以使用以下方法|99994|/**+A+safe+way+to+get+an+instance+of+the+Camera+object.+*/
public+Camera+getCameraInstance()+{
++++Camera+c+=+null;
++++try+{
++++++++c+=+Camera.open();+//+attempt+to+get+a+Camera+instance
++++++++Parameters+p+=+c.getParameters();
++++++++List<Size>+sizes+=+p.getSupportedPictureSizes();

++++++++Size+x+=+null;

++++++++if+(sizes.size()+<+1)+{
++++++++++++throw+new+Exception("there+are+not+supported+picture+sizes+at+all+!!!");
++++++++}

++++++++for+(Size+s+:+sizes)+{
++++++++++++if+(s.width+==+640+&&+s.height+==+480)+{
++++++++++++++++x+=+s;
++++++++++++}
++++++++}

++++++++if+(x+==+null)+{
++++++++++++x+=+sizes.get(0);
++++++++++++p.setPictureSize(x.width,+x.height);
++++++++}+else+{
++++++++++++p.setPictureSize(640,+480);
++++++++}
++++++++p.setJpegQuality(20);
++++++++p.setGpsLatitude(MapViewer.latitude);
++++++++p.setGpsLongitude(MapViewer.longitude);
++++++++c.setParameters(p);
++++}+catch+(Exception+e)+{
++++++++//+Camera+is+not+available+(in+use+or+does+not+exist)
++++++++Log.d(TAG+%2B+"(getCameraInstance)",+e.getMessage());
++++}
++++return+c;+//+returns+null+if+camera+is+unavailable
}|99995|entityMap^0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|X|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Y|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|Z|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|10|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|11|8|@]|9|@]|A|$]]|$1|O|3|P|5|F|7|12|8|@]|9|@]|A|$G|H]]|$1|Q|3|R|5|6|7|13|8|@]|9|@]|A|$]]|$1|S|3|T|5|F|7|14|8|@]|9|@]|A|$G|H]]|$1|U|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|V|$]]

I don't have an fully working example, but I can give you snippets from an project of mine where I also put the camera previews in an smaller view than the full screen. I just want to convey the idea.

What you need is a FrameLayout which will hold the camera preview

<pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:id="@+id/absoluteLayout1"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:background="@android:color/transparent"
 android:orientation="vertical" &gt;

 &lt;FrameLayout
 android:id="@+id/camera_preview"
 android:layout_width="200dp"
 android:layout_height="200dip" &gt;
 &lt;/FrameLayout&gt;

&lt;/RelativeLayout&gt;
</code></pre>

Now we need a PreviewListener which is also an View

<pre><code>import java.io.IOException;

import android.content.Context;
import android.hardware.Camera;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

/** A basic Camera preview class */
public class CameraPreviewListener extends SurfaceView implements SurfaceHolder.Callback {
 private SurfaceHolder mHolder;
 private Camera mCamera;

 public CameraPreviewListener(Context context, Camera camera) {
 super(context);
 mCamera = camera;

 // Install a SurfaceHolder.Callback so we get notified when the
 // underlying surface is created and destroyed.
 mHolder = getHolder();
 mHolder.addCallback(this);

 // deprecated setting, but required on Android versions prior to 3.0
 mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
 }

 public void surfaceCreated(SurfaceHolder holder) {
 // The Surface has been created, now tell the camera where to draw the preview.
 mCamera.setPreviewDisplay(holder);
 mCamera.startPreview();
 }

 public void surfaceDestroyed(SurfaceHolder holder) {
 // Take care of releasing the Camera preview in your activity.
 Log.d("camera", "surfaceDestroyed");
 if(holder.equals(mHolder)){
 holder.removeCallback(this); 
 }else{
 holder.removeCallback(this);
 mHolder.removeCallback(this);
 }
 }

 public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
 // If your preview can change or rotate, take care of those events here.
 // Make sure to stop the preview before resizing or reformatting it.

 if (mHolder.getSurface() == null){
 // preview surface does not exist
 return;
 }

 // stop preview before making changes
 try {
 mCamera.stopPreview();

 } catch (Exception e){
 e.printStackTrace();
 // ignore: tried to stop a non-existent preview
 }

 // set preview size and make any resize, rotate or
 // reformatting changes here

 // start preview with new settings
 try {
 mCamera.setPreviewDisplay(mHolder);
 mCamera.startPreview();

 } catch (Exception e){
 Log.d("camera", "Error starting camera preview: " + e.getMessage());
 }
 }

 public void removeCallback(){
 mHolder = getHolder();
 mHolder.removeCallback(this);
 }
}
</code></pre>

Finally you need to assemble everything in you activity

<pre><code>import android.hardware.Camera;

Camera mCamera = = getCameraInstance();
CameraPreviewListener cpl = new CameraPreviewListener(this, mCamera);
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.addView(cpl);
</code></pre>

To get the camera you can use the following method

<pre><code>/** A safe way to get an instance of the Camera object. */
public Camera getCameraInstance() {
 Camera c = null;
 try {
 c = Camera.open(); // attempt to get a Camera instance
 Parameters p = c.getParameters();
 List&lt;Size&gt; sizes = p.getSupportedPictureSizes();

 Size x = null;

 if (sizes.size() &lt; 1) {
 throw new Exception("there are not supported picture sizes at all !!!");
 }

 for (Size s : sizes) {
 if (s.width == 640 &amp;&amp; s.height == 480) {
 x = s;
 }
 }

 if (x == null) {
 x = sizes.get(0);
 p.setPictureSize(x.width, x.height);
 } else {
 p.setPictureSize(640, 480);
 }
 p.setJpegQuality(20);
 p.setGpsLatitude(MapViewer.latitude);
 p.setGpsLongitude(MapViewer.longitude);
 c.setParameters(p);
 } catch (Exception e) {
 // Camera is not available (in use or does not exist)
 Log.d(TAG + "(getCameraInstance)", e.getMessage());
 }
 return c; // returns null if camera is unavailable
}
</code></pre>

blocks|key|317016|text|希望这和你一起工作，你可以在不打开相机应用程序的情况下从后台捕捉图像|type|unstyled|depth|inlineStyleRanges|entityRanges|data|317017|https://stackoverflow.com/a/24849344/1312796|offset|length|317018|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|18|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@$D|O|E|P|1|Q]]|A|$]]|$1|F|3|-4|5|6|7|R|8|@]|9|@]|A|$]]]|G|$H|$5|I|J|K|A|$L|C]]]]

Hope this work with you, You can capture image from background without opening camera app 

<a href="https://stackoverflow.com/a/24849344/1312796">https://stackoverflow.com/a/24849344/1312796</a>

I need to continuously scan QR codes in my Android app while the main View of the app is on the screen. The main view should contain a window with camera preview, but not a fullscreen camera preview. 

An example of usage: Main view containing a list of scanned QR codes and a camera preview. When new QR code is scanned, it is added to the list. 

Is it possible?

QR code scanning without fullscreen camera

Android

我需要在我的安卓应用程序中连续扫描二维码，而应用程序的主视图在屏幕上。主视图应包含带相机预览的窗口，但不应包含全屏相机预览。一个用法示例:包含扫描的二维码列表和相机预览的主视图。当扫描到新的二维码时，它会被添加到列表中。有可能吗？

问无需全屏摄像头的二维码扫描
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