基于Android TextureView与SurfaceTexture实现相机Camera拍照预览与保存照片

向右看齐 2023-10-17 15:48 153阅读 0赞

基于Android TextureView与SurfaceTexture实现相机Camera拍照预览与保存照片

写一个简单的例子，实现一个常见的开发功能：拍照功能。
技术路线：通过TextureView的通道获取SurfaceTexture作为相机的预览，然后通过Camera的take方法把相机抓取的byte字节数据转换为Bitmap，然后存放到手机的存储器上，至此，一个最简单的拍照功能完成。
注意，本例如果运行在Android高版本（6.0+，7.0+或更高），需要多写运行时权限申请代码。本例出于功能演示，不再冗余的写这部分代码。只给出最骨干的关键代码逻辑。

布局文件activity_main.xml：

  1. <?xml version="1.0" encoding="utf-8"?>
  2. <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  3.     xmlns:tools="http://schemas.android.com/tools"
  4.     android:layout_width="match_parent"
  5.     android:layout_height="match_parent"
  6.     android:background="@android:color/holo_blue_light"
  7.     tools:context="zhangphil.view.MainActivity">
  9.     <zhangphil.view.MyTextureView
  10.         android:id="@+id/textureView"
  11.         android:layout_width="300dp"
  12.         android:layout_height="200dp"
  13.         android:layout_centerInParent="true" />
  15.     <Button
  16.         android:id="@+id/capture"
  17.         android:layout_width="wrap_content"
  18.         android:layout_height="wrap_content"
  19.         android:layout_alignParentBottom="true"
  20.         android:layout_centerHorizontal="true"
  21.         android:text="拍摄" />
  22. </RelativeLayout>

MyTextureView.java： 

  1. package zhangphil.view;
  3. import android.content.Context;
  4. import android.graphics.Bitmap;
  5. import android.graphics.BitmapFactory;
  6. import android.graphics.SurfaceTexture;
  7. import android.hardware.Camera;
  8. import android.os.Environment;
  9. import android.util.AttributeSet;
  10. import android.util.Log;
  11. import android.view.TextureView;
  13. import java.io.BufferedOutputStream;
  14. import java.io.File;
  15. import java.io.FileOutputStream;
  17. /**
  18.  * Created by Phil on 2017/9/13.
  19.  */
  21. public class MyTextureView extends TextureView {
  22.     public Camera mCamera;
  24.     public MyTextureView(Context context, AttributeSet attrs) {
  25.         super(context, attrs);
  26.         init();
  27.     }
  29.     private void init() {
  30.         mCamera = Camera.open();
  32.         this.setSurfaceTextureListener(new SurfaceTextureListener() {
  34.             @Override
  35.             public void onSurfaceTextureAvailable(SurfaceTexture surfaceTexture, int width, int height) {
  36.                 try {
  37.                     mCamera.setPreviewTexture(surfaceTexture);
  38.                     mCamera.startPreview();
  39.                 } catch (Exception e) {
  40.                     e.printStackTrace();
  41.                 }
  42.             }
  44.             @Override
  45.             public void onSurfaceTextureSizeChanged(SurfaceTexture surfaceTexture, int width, int height) {
  47.             }
  49.             @Override
  50.             public boolean onSurfaceTextureDestroyed(SurfaceTexture surfaceTexture) {
  51.                 mCamera.stopPreview();
  52.                 mCamera.release();
  53.                 mCamera = null;
  55.                 return true;
  56.             }
  58.             @Override
  59.             public void onSurfaceTextureUpdated(SurfaceTexture surfaceTexture) {
  61.             }
  62.         });
  63.     }
  65.     public void take() {
  66.         if(mCamera!=null)
  67.             mCamera.takePicture(null, null, mPictureCallback);
  68.     }
  70.     Camera.PictureCallback mPictureCallback = new Camera.PictureCallback() {
  71.         @Override
  72.         public void onPictureTaken(byte[] data, Camera camera) {
  73.             mCamera.stopPreview();
  74.             new FileSaver(data).save();
  75.         }
  76.     };
  78.     private class FileSaver implements Runnable {
  79.         private byte[] buffer;
  81.         public FileSaver(byte[] buffer) {
  82.             this.buffer = buffer;
  83.         }
  85.         public void save() {
  86.             new Thread(this).start();
  87.         }
  89.         @Override
  90.         public void run() {
  91.             try {
  92.                 File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM), "zhangphil.png");
  93.                 file.createNewFile();
  95.                 FileOutputStream os = new FileOutputStream(file);
  96.                 BufferedOutputStream bos = new BufferedOutputStream(os);
  98.                 Bitmap bitmap = BitmapFactory.decodeByteArray(buffer, 0, buffer.length);
  99.                 bitmap.compress(Bitmap.CompressFormat.PNG, 100, bos);
  101.                 bos.flush();
  102.                 bos.close();
  103.                 os.close();
  105.                 Log.d("照片已保存", file.getAbsolutePath());
  107.                 mCamera.startPreview();
  108.             } catch (Exception e) {
  109.                 e.printStackTrace();
  110.             }
  111.         }
  112.     }
  113. }

MainActivity.java：

  1. package zhangphil.view;
  3. import android.support.v7.app.AppCompatActivity;
  4. import android.os.Bundle;
  5. import android.view.View;
  7. public class MainActivity extends AppCompatActivity {
  8.     private MyTextureView textureView;
  10.     @Override
  11.     protected void onCreate(Bundle savedInstanceState) {
  12.         super.onCreate(savedInstanceState);
  13.         setContentView(R.layout.activity_main);
  14.         textureView = (MyTextureView) findViewById(R.id.textureView);
  15.         findViewById(R.id.capture).setOnClickListener(new View.OnClickListener() {
  16.             @Override
  17.             public void onClick(View view) {
  18.                 textureView.take();
  19.             }
  20.         });
  21.     }
  22. }

权限：

  1. <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
  2.     <uses-permission android:name="android.permission.CAMERA"/>

代码运行结果：

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