编辑：正如Oren Bengigi建议的那样，我尝试将一些代码保存在post(Runnable)中，但我仍然得到相同的结果：
final Handler handler = new Handler();
void savePicture(final byte[] data) {
handler.post(new Runnable() {
public void run() {
try {
FrameLayout view = (FrameLayout)findViewById(R.id.image);
view.setDrawingCacheEnabled(true);
Bitmap b = view.getDrawingCache();
b.compress(CompressFormat.PNG, 50, new FileOutputStream(Environment.getExternalStorageDirectory() + String.format(
"/SimpleBulb/%d.png", System.currentTimeMillis())));
Log.d(TAG, "onPictureTaken - wrote bytes: " + data.length);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
}
}
});
}
我正在尝试使用叠加图片并将两者保存为一个.png。我可以保存相机拍摄的图像，并且我可以保存叠加层，但是当我尝试将两者保存为一个图像时，我只能看到叠加层和黑色背景。我已经切换了两个图层，整个图像都是黑色的，因此相机中的图像只是呈现黑色。任何有关这方面的帮助都将非常感激。这是我的代码：
package com.commonsware.android.skeleton;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.Bitmap.CompressFormat;
import android.graphics.BitmapFactory;
import android.hardware.Camera;
import android.hardware.Camera.*;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.Display;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;
// ----------------------------------------------------------------------
public class SimpleBulbActivity extends Activity {
private Preview mPreview;
private static final String TAG = "CameraDemo";
RelativeLayout preview;
Camera mCamera;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Hide the window title.
requestWindowFeature(Window.FEATURE_NO_TITLE);
// create a File object for the parent directory
File imageDirectory = new File(Environment.getExternalStorageDirectory() + "/SimpleBulb/");
// Check if the directory exists
if(!imageDirectory.exists()) {
// have the object build the directory structure, if needed.
imageDirectory.mkdirs();
}
setContentView(R.layout.main);
}
protected void onResume() {
super.onResume();
//Setup the FrameLayout with the Camera Preview Screen
mPreview = new Preview(this);
preview = (RelativeLayout)findViewById(R.id.preview);
preview.addView(mPreview);
}
public void snap(View view) {
mCamera.takePicture(shutterCallback, rawCallback, jpegCallback);
}
ShutterCallback shutterCallback = new ShutterCallback() {
public void onShutter() {
Log.d(TAG, "onShutter'd");
}
};
PictureCallback rawCallback = new PictureCallback() {
public void onPictureTaken(byte[] _data, Camera _camera) {
Log.d(TAG, "onPictureTaken - raw");
}
};
PictureCallback jpegCallback = new PictureCallback() {
public void onPictureTaken(byte[] data, Camera _camera) {
FileOutputStream outStream = null;
try {
// write to local sandbox file system
// outStream =
// CameraDemo.this.openFileOutput(String.format("%d.jpg",
// System.currentTimeMillis()), 0);
// Save image to SD Card
/*BitmapFactory.Options options=new BitmapFactory.Options();
options.inSampleSize = 5;
String filename = Environment.getExternalStorageDirectory() + String.format(
"/SimpleBulb/%d.png", System.currentTimeMillis());
Bitmap myImage = BitmapFactory.decodeByteArray(data, 0,data.length,options);
outStream = new FileOutputStream(filename);
BufferedOutputStream bos = new BufferedOutputStream(outStream);
myImage.compress(CompressFormat.PNG, 95, bos);
bos.flush();
bos.close();
// Replace view with Picture taken
ImageView cameraImage = (ImageView)findViewById(R.id.taken_image);
cameraImage.setImageBitmap(myImage);*/
// Save as one
FrameLayout view = (FrameLayout)findViewById(R.id.image);
view.setDrawingCacheEnabled(true);
Bitmap b = view.getDrawingCache();
b.compress(CompressFormat.PNG, 50, new FileOutputStream(Environment.getExternalStorageDirectory() + String.format(
"/SimpleBulb/%d.png", System.currentTimeMillis())));
Log.d(TAG, "onPictureTaken - wrote bytes: " + data.length);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
}
Log.d(TAG, "onPictureTaken - jpeg");
}
};
// ----------------------------------------------------------------------
class Preview extends SurfaceView implements SurfaceHolder.Callback {
SurfaceHolder mHolder;
Preview(Context context) {
super(context);
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, acquire the camera and tell it where
// to draw.
mCamera = Camera.open();
try {
mCamera.setPreviewDisplay(holder);
mCamera.setPreviewCallback(new PreviewCallback() {
public void onPreviewFrame(byte[] data, Camera arg1) {
Log.d(TAG, "onPreviewFrame - wrote bytes: "
+ data.length);
Preview.this.invalidate();
}
});
} catch (IOException e) {
mCamera.release();
mCamera = null;
e.printStackTrace();
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// Surface will be destroyed when we return, so stop the preview.
// Because the CameraDevice object is not a shared resource, it's very
// important to release it when the activity is paused.
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
final double ASPECT_TOLERANCE = 0.05;
double targetRatio = (double) w / h;
if (sizes == null) return null;
Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = h;
// Try to find an size match aspect ratio and size
for (Size size : sizes) {
double ratio = (double) size.width / size.height;
if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
// Cannot find the one match the aspect ratio, ignore the requirement
if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Size size : sizes) {
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
}
return optimalSize;
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// Now that the size is known, set up the camera parameters and begin
// the preview.
Camera.Parameters parameters = mCamera.getParameters();
List<Size> sizes = parameters.getSupportedPreviewSizes();
Size optimalSize = getOptimalPreviewSize(sizes, w, h);
Display display = ((WindowManager)getSystemService(WINDOW_SERVICE)).getDefaultDisplay();
if(display.getRotation() == Surface.ROTATION_0)
{
parameters.setPreviewSize(optimalSize.height, optimalSize.width);
mCamera.setDisplayOrientation(90);
}
if(display.getRotation() == Surface.ROTATION_90)
{
parameters.setPreviewSize(optimalSize.width, optimalSize.height);
}
if(display.getRotation() == Surface.ROTATION_180)
{
parameters.setPreviewSize(optimalSize.width, optimalSize.height);
}
if(display.getRotation() == Surface.ROTATION_270)
{
parameters.setPreviewSize(optimalSize.width, optimalSize.height);
mCamera.setDisplayOrientation(0);
}
mCamera.setParameters(parameters);
mCamera.startPreview();
}
}
}
这是我的布局：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent" android:id="@+id/layout">
<FrameLayout android:id="@+id/image" android:layout_weight="1" android:layout_width="fill_parent"
android:layout_height="fill_parent">
<RelativeLayout android:id="@+id/preview"
android:layout_weight="1" android:layout_width="fill_parent"
android:layout_height="fill_parent">
</RelativeLayout>
<RelativeLayout android:id="@+id/bulb_pic" android:layout_width="match_parent" android:layout_height="112dip">
<ImageView android:id="@+id/bulb" android:src="@drawable/litbulb"
android:layout_width="match_parent"
android:layout_height="112dip" />
</RelativeLayout>
</FrameLayout>
<Button android:layout_width="match_parent"
android:layout_height="wrap_content" android:id="@+id/buttonClick"
android:text="Snap!" android:layout_gravity="center" android:onClick="snap"></Button>
</LinearLayout>
答案 0 :(得分：2)
可能是您设置的ImageView没有立即更新。 我会尝试运行以下代码：
Bitmap b = view.getDrawingCache();
b.compress(CompressFormat.PNG, 50, new FileOutputStream(Environment.getExternalStorageDirectory() + String.format(
"/SimpleBulb/%d.png", System.currentTimeMillis())));
Log.d(TAG, "onPictureTaken - wrote bytes: " + data.length);
在具有postRunaable的处理程序中，看看它是否有效。