Android相机Camera基础知识

一、概述
本章节主要讲述的Android相机Camera的相关知识点，主要包含三个方面，Android启动系统相机生成缩略图、Android启动系统相机生成原图以及Android自定义相机等。

二、Android启动系统相机

核心代码：

package com.czhappy.camerademo.activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.ImageView;
import com.czhappy.camerademo.R;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
public class MainActivity extends AppCompatActivity {
private static int REQ_1 = 1;
private static int REQ_2 = 2;
private ImageView image_iv;
private String mFilePath;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
image_iv = (ImageView) findViewById(R.id.image_iv);
mFilePath = Environment.getExternalStorageDirectory().getPath();
mFilePath = mFilePath +"/" + System.currentTimeMillis()+".jpg";
}
public void startCamera1(View view){
//隐式Intent调用
Intent it = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(it, REQ_1);
}
public void startCamera2(View view){
//隐式Intent调用
Intent it = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
Uri photoUri = Uri.fromFile(new File(mFilePath));
it.putExtra(MediaStore.EXTRA_OUTPUT, photoUri);
startActivityForResult(it, REQ_2);
}
public void customCamera(View view){
Intent it = new Intent(MainActivity.this, CustomCameraActivity.class);
startActivity(it);
}
/**
*
* @param requestCode
* @param resultCode
* @param data //缩略图
*/
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(resultCode == RESULT_OK){
if(requestCode == REQ_1){//缩略图
Bundle bundle = data.getExtras();
Bitmap bmp = (Bitmap) bundle.get("data");
image_iv.setImageBitmap(bmp);
}else if(requestCode == REQ_2){//原图
FileInputStream fis = null;
try {
fis = new FileInputStream(mFilePath);
Bitmap bitmap = BitmapFactory.decodeStream(fis);
image_iv.setImageBitmap(bitmap);
} catch (FileNotFoundException e) {
e.printStackTrace();
}finally {
try {
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
}

三、Android自定义相机

1.自定义相机步骤：

创建相机
创建SurfaceView
关联相机与SurfaceView
调整相机显示效果
自定义相机预览界面

2.核心代码：
自定义相机CustomCameraActivity.java

package com.czhappy.camerademo.activity;
import android.content.Intent;
import android.graphics.ImageFormat;
import android.hardware.Camera;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import com.czhappy.camerademo.R;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
/**
* Description:
* User: chenzheng
* Date: 2016/12/27 0027
* Time: 13:43
*/
public class CustomCameraActivity extends AppCompatActivity implements SurfaceHolder.Callback{
private SurfaceView mPreview;
private Camera mCamera;
private SurfaceHolder mHolder;
private Camera.PictureCallback mPictureCallback = new Camera.PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
File tempFile = new File("/sdcard/temp.png");
try {
FileOutputStream fos = new FileOutputStream(tempFile);
fos.write(data);
fos.close();
Intent it = new Intent(CustomCameraActivity.this, CaptureResultActivity.class);
it.putExtra("picPath", tempFile.getAbsolutePath());
startActivity(it);
finish();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_custom_camera);
mPreview = (SurfaceView) this.findViewById(R.id.preview);
mHolder = mPreview.getHolder();
mHolder.addCallback(this);
//点击自动对焦
mPreview.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
mCamera.autoFocus(null);;
}
});
}
/**
* 拍照
* @param view
*/
public void capture(View view){
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPictureFormat(ImageFormat.JPEG);
parameters.setPictureSize(800,400);
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);//自动对焦
mCamera.autoFocus(new Camera.AutoFocusCallback() {
@Override
public void onAutoFocus(boolean success, Camera camera) {
//对焦准确拍摄照片
if(success){
mCamera.takePicture(null, null, mPictureCallback);
}
}
});
}
/**
* 获取相机对象
* @return
*/
private Camera getCamera(){
mCamera = Camera.open();
return mCamera;
}
/**
* 开始预览相机内容
*/
private void setStartPreview(Camera camera, SurfaceHolder holder){
try {
camera.setPreviewDisplay(holder);
camera.setDisplayOrientation(90);//设置相机预览为竖屏90度
camera.startPreview();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 释放相机资源
*/
private void releaseCamera(){
if(mCamera!=null){
mCamera.setPreviewCallback(null);
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
}
@Override
protected void onResume() {
super.onResume();
if (mCamera==null){
mCamera = getCamera();
if(mHolder!=null){
setStartPreview(mCamera, mHolder);
}
}
}
@Override
protected void onPause() {
super.onPause();
releaseCamera();
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
setStartPreview(mCamera, mHolder);
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
mCamera.stopPreview();
setStartPreview(mCamera, mHolder);
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
releaseCamera();
}
}

生成图片结果页面CaptureResultActivity.java

package com.czhappy.camerademo.activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.ImageView;
import com.czhappy.camerademo.R;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
/**
* Description:
* User: chenzheng
* Date: 2016/12/30 0030
* Time: 13:27
*/
public class CaptureResultActivity extends AppCompatActivity {
private String picPath;
private ImageView result_iv;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_capture_result);
picPath = getIntent().getStringExtra("picPath");
result_iv = (ImageView) findViewById(R.id.result_iv);
try {
FileInputStream fis = new FileInputStream(picPath);
Bitmap bitmap = BitmapFactory.decodeStream(fis);
Matrix matrix = new Matrix();
matrix.setRotate(90);//旋转90度矩阵
bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
result_iv.setImageBitmap(bitmap);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}

四、项目源代码下载

http://xiazai.jb51.net/201701/yuanma/AndroidCamera(jb51.net).rar

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。

您可能感兴趣的文章:

• Android编程调用Camera和相册功能详解
• Android camera实时预览 实时处理，人脸识别示例
• Android自定义照相机Camera出现黑屏的解决方法
• Android利用Camera实现中轴3D卡牌翻转效果
• Android编程中调用Camera时预览画面有旋转问题的解决方法
• Android Camera是否支持变焦的判断方法总结
• Android Camera变焦编程步骤
• Android camera2 判断相机功能是否可控的实例