How to achieve the custom function of the Camera View framework through the Java class library
How to achieve the custom function of the Camera View framework through the Java class library
Summary:
Camera view is one of the common functions in mobile applications. It uses households to take photos and recording videos.By using the Java library, developers can customize the camera view function to meet different application needs.This article will discuss how to achieve the custom function of the Camera View framework through the Java class library and provide some Java code examples.
introduce:
Camera view is one of the very common functions in modern mobile applications. Users can use it to take photos and record videos.The Java class library provides some powerful tools and interfaces, and developers can use these tools and interfaces to delineate the behavior and appearance of the camera view.By customized camera view functions, developers can realize some unique application scenarios and user experience.
Implementation steps:
1. Import the required Java class library
In the project construction file, add the dependencies of the Java library required.Here, we will use the Android camera API and Camera class libraries to customize the camera view.
2. Setting permissions
In the AndroidManifest.xml file, a camera and recording authority is set.These permissions will allow applications to access the cameras and microphones of the device.
Example code:
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />
3. Create a custom Cameraview class
Create a new Java class, named Cameraview, and inherit the Android SurfaceView class.In the CameraView class, use the Camera class library to achieve the function of custom camera view.
Example code:
public class CameraView extends SurfaceView implements SurfaceHolder.Callback {
private Camera mCamera;
public CameraView(Context context) {
super(context);
getHolder().addCallback(this);
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
mCamera = Camera.open();
try {
mCamera.setPreviewDisplay(holder);
} catch (IOException e) {
// Treatment abnormalities
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
mCamera.stopPreview();
mCamera.release();
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
// Add the size and preview of the camera view here
mCamera.startPreview();
}
}
In the above sample code, we created a custom class called Cameraview and set a recovery function of SurfaceView in the constructor.In the SurfaceCreated method, we turn on the camera and set the preview image to SurfaceHolder.In the SurfaceDestroyed method, we stop previewing and release camera resources.In the SurfaceChanged method, we can adjust the size and preview of the camera view.
4. Use the custom Cameraview in the layout file
Use the custom Cameraview in the XML layout file to display the custom camera view.
Example code:
<com.example.myapplication.CameraView
android:id="@+id/cameraView"
android:layout_width="match_parent"
android:layout_height="match_parent" />
5. Control the camera function through Java code
With the Java code, you can further customize the behavior of the camera view.For example, you can control functions such as the focal length, flash and white balance of the camera.
Example code:
// Change focal length
Camera.Parameters params = mCamera.getParameters();
Params.setzoom (2); // Set the focal length to 2
mCamera.setParameters(params);
// Control the flash
if (getContext().getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH)) {
// Equipment support flash
Camera.Parameters params = mCamera.getParameters();
params.setFlashMode(Camera.Parameters.FLASH_MODE_ON);
mCamera.setParameters(params);
}
// Set white balance
Camera.Parameters params = mCamera.getParameters();
params.setWhiteBalance(Camera.Parameters.WHITE_BALANCE_AUTO);
mCamera.setParameters(params);
In the above example code, we demonstrated how to use the Java code to change the focal length of the camera, control the flash, and set the white balance.
in conclusion:
Through the Java library, developers can easily customize the function and appearance of the camera view.The example code in this article shows how to use Android Camera class libraries and some Java code to achieve custom camera views.Developers can further expand and customize camera view functions according to their needs to create unique and excellent mobile applications.
