我正在尝试制作一个应用程序作为我的项目的一部分，我需要用屏幕本身提供的不同颜色照亮我正在拍摄的物体（前置摄像头）。我是android编程的新手，到目前为止只能访问相机（后面的那个，因为根据我的研究，不可能通过意图自动访问前面的那个），给它拍照并展示出来。
在拍照时，我需要不同的颜色来照亮它。我听说这在 iOS 中可以使用某些版本的 snapchat，它创建一个“模拟”闪光灯，以白色照亮前屏幕。我怎么能操纵它来获得其他颜色？
【问题讨论】：
知道了。
这实际上很简单，只是让我觉得自己像个傻瓜，并意识到我对 java 和 android 开发的整体了解是多么的少:D
我可以通过将surfaceView 应用到全屏来做到这一点，所以它是一个简单的XML
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">
<RelativeLayout
android:id="@+id/btn_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!-- Background changed on the surfaceview so far-->
<SurfaceView
android:id="@+id/surfaceView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentBottom="true"
android:background="#9AE916" />
</RelativeLayout>
</FrameLayout>之后，我只需访问相机并使用音量增大按钮更改颜色。到目前为止，它是硬编码的
public class CameraActivity extends AppCompatActivity implements SurfaceHolder.Callback {
Camera camera;
@InjectView(R.id.surfaceView)
SurfaceView surfaceView;
SurfaceHolder surfaceHolder;
Camera.PictureCallback jpegCallback;
Camera.ShutterCallback shutterCallback;
public int color_flag = 0;
@Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.camera_activity);
ButterKnife.inject(this);
surfaceView = (SurfaceView) findViewById(R.id.surfaceView);
surfaceHolder = surfaceView.getHolder();
//Install a surfaceHolder.Callback so we get notified when the underlying surface is created and destroyed
surfaceHolder.addCallback(this);
//deprecated setting, but required on android versions prior to 3.0
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
//Sets brightness to max value
WindowManager.LayoutParams layout = getWindow().getAttributes();
layout.screenBrightness = 1;
getWindow().setAttributes(layout);
jpegCallback = new Camera.PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
//TODO takes care of rotation ------------------------------------------------------
if(data != null){
int screenWidth = getResources().getDisplayMetrics().widthPixels;
int screenHeight = getResources().getDisplayMetrics().heightPixels;
Bitmap bm = BitmapFactory.decodeByteArray(data, 0, (data != null) ? data.length : 0);
if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) {
// Notice that width and height are reversed
Bitmap scaled = Bitmap.createScaledBitmap(bm, screenHeight, screenWidth, true);
int w = scaled.getWidth();
int h = scaled.getHeight();
// Setting post rotate to 90
Matrix mtx = new Matrix();
mtx.postRotate(90);
// Rotating Bitmap
bm = Bitmap.createBitmap(scaled, 0, 0, w, h, mtx, true);
}else{// LANDSCAPE MODE
//No need to reverse width and height
Bitmap scaled = Bitmap.createScaledBitmap(bm, screenWidth,screenHeight , true);
bm=scaled;
}
}
//TODO assign bitmap to be saved----------------------------------------------------
FileOutputStream outputStream = null;
File file_image= getDirc();
if (!file_image.exists() && !file_image.mkdirs()){
Toast.makeText(getApplicationContext(), "Can't create directory to save",Toast.LENGTH_LONG).show();
return;
}
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyyMMdd-HHmmss");
String date = simpleDateFormat.format(new Date());
String photofile = "SP_Interface" +date+".jpg";
String file_name = file_image.getAbsolutePath()+ "/" + photofile;
File picfile = new File(file_name);
try{
outputStream = new FileOutputStream(picfile);
outputStream.write(data);
outputStream.close();
} catch (FileNotFoundException e){
} catch (IOException ex) {
} finally {
}
Toast.makeText(getApplicationContext(),"Picture saved",Toast.LENGTH_SHORT).show();
refreshCamera();
refreshGallery(picfile);
}
};
}
private void refreshGallery(File file){
Intent intent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
intent.setData(Uri.fromFile(file));
sendBroadcast(intent);
}
public void refreshCamera(){
if(surfaceHolder.getSurface()==null){
//preview surface does not exist
return;
}
//stop preview before making changes
try {
camera.stopPreview();
} catch (Exception e) {
}
//set preview size and make any resize, rotate or reformatting changes here. Start preview with new settings
try{
camera.setPreviewDisplay(surfaceHolder);
camera.startPreview();
}catch (Exception e){}
}
private File getDirc(){
File dics = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM);
return new File(dics,"SP_Interface");
}
public void cameraImage(){
//take the picture
camera.takePicture(null,null,jpegCallback);
}
@Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
//open the FRONT camera
try {
camera = Camera.open(1);
} catch (RuntimeException ex) {
}
Camera.Parameters parameters;
parameters = camera.getParameters();
//modify parameter
parameters.setPreviewFrameRate(20);
parameters.setPreviewSize(352,288);
camera.setParameters(parameters);
camera.setDisplayOrientation(90);
try{
//The surface has been created, now tell the camera where to draw the preview
camera.setPreviewDisplay(surfaceHolder);
camera.startPreview();
}catch(Exception e){}
}
public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {
refreshCamera();
}
@Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
//stop preview and release the camera
camera.stopPreview();
camera.release();
camera=null;
}
//Volume up changes to next color
@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
super.onKeyUp(keyCode, event);
if (keyCode == KeyEvent.KEYCODE_VOLUME_UP)
{
switch (color_flag){
case 0:
color_flag+=1;
surfaceView.setBackgroundColor(Color.parseColor("#0000FF"));
break;
case 1:
color_flag+=1;
surfaceView.setBackgroundColor(Color.parseColor("#00FFFF"));
break;
case 2:
color_flag+=1;
surfaceView.setBackgroundColor(Color.parseColor("#FF00FF"));
break;
case 3:
color_flag+=1;
surfaceView.setBackgroundColor(Color.parseColor("#00FF00"));
break;
}
return true;
}
return false;
}
//Volume down takes the picture
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
super.onKeyDown(keyCode, event);
if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN)
{
camera.takePicture(null,null,jpegCallback);
return true;
}
return false;
}
}希望它对某人有所帮助！
提示：更多地研究布局，在您了解它们的工作原理之后，您可以做很多事情
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