Android Camera相关操作，调用手机应用

迷南。 2024-04-17 22:24 31阅读 0赞

![在这里插入图片描述][20190902091953267.png]  
一、首先我们先调用系统相机  
MainActivity

import androidx.annotation.Nullable;
    import androidx.appcompat.app.AppCompatActivity;
    
    import android.content.Intent;
    import android.graphics.Bitmap;
    import android.os.Bundle;
    import android.provider.MediaStore;
    import android.view.View;
    import android.widget.ImageView;
    
    public class MainActivity extends AppCompatActivity {
    
        ImageView imageView;
        private int REQ_1;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            imageView=findViewById(R.id.imageView);
        }
    
    
        public void goCamera(View view){
            //调用系统相机
           Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
           startActivityForResult(intent,REQ_1);
       }
        @Override
        protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
            super.onActivityResult(requestCode, resultCode, data);
            if (resultCode == RESULT_OK){
                if (requestCode == REQ_1){
                    Bundle bundle = data.getExtras();
                    Bitmap bitmap = (Bitmap) bundle.get("data");
                    imageView.setImageBitmap(bitmap);
                }
            }
        }
    
    }

xml

<?xml version="1.0" encoding="utf-8"?>
    <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">
    
        <Button
            android:id="@+id/button"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="goCamera"
            app:layout_constraintTop_toTopOf="parent"
            android:onClick="goCamera"
            tools:layout_editor_absoluteX="166dp"
            tools:layout_editor_absoluteY="225dp"
            tools:ignore="MissingConstraints,OnClick" />
    
        <ImageView
            android:id="@+id/imageView"
            android:layout_width="0dp"
            android:layout_height="0dp"
            app:layout_constraintTop_toBottomOf="@+id/button"
            tools:srcCompat="@tools:sample/backgrounds/scenic"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            tools:ignore="MissingConstraints" />
    </androidx.constraintlayout.widget.ConstraintLayout>

效果：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIxNDgwNjA3_size_16_color_FFFFFF_t_70]  
从图中我们可以看出拍摄的图比显示的图要清楚，只是因为Android为防止内存崩溃，从而返回略缩图。  
解决方法：将拍摄图片保存至手机内存，然后从手机内存读取图片。  
改进如下：

import androidx.annotation.Nullable;
    import androidx.appcompat.app.AppCompatActivity;
    import androidx.core.app.ActivityCompat;
    import androidx.core.content.ContextCompat;
    
    import android.Manifest;
    import android.content.Intent;
    import android.content.pm.PackageManager;
    import android.graphics.Bitmap;
    import android.graphics.BitmapFactory;
    import android.net.Uri;
    import android.os.Bundle;
    import android.os.Environment;
    import android.os.StrictMode;
    import android.provider.MediaStore;
    import android.view.View;
    import android.widget.ImageView;
    
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.IOException;
    
    public class MainActivity extends AppCompatActivity {
    
        ImageView imageView;
        private int REQ_1=1;
        private int REQ_2=2;
        private String storePath;
        private static final int WRITE_EXTERNAL_STORAGE_REQUEST_CODE = 201;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            imageView=findViewById(R.id.imageView);
            StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
            StrictMode.setVmPolicy(builder.build());
            builder.detectFileUriExposure();
    
        }
    
    
        public void goCamera(View view){
            if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
                    != PackageManager.PERMISSION_GRANTED) {
                //申请WRITE_EXTERNAL_STORAGE权限
                ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                        WRITE_EXTERNAL_STORAGE_REQUEST_CODE);
            }
            //调用系统相机
           Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
           storePath = Environment.getExternalStorageDirectory().getPath() + File.separator +"mycamera.jpg"; 
            Uri photoUri = Uri.fromFile(new File(storePath));
            intent.putExtra(MediaStore.EXTRA_OUTPUT,photoUri);
           startActivityForResult(intent,REQ_2);
       }
        @Override
        protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
            super.onActivityResult(requestCode, resultCode, data);
            if (resultCode == RESULT_OK){
                if (requestCode == REQ_1){
                    Bundle bundle = data.getExtras();
                    Bitmap bitmap = (Bitmap) bundle.get("data");
                    imageView.setImageBitmap(bitmap);
                }else if (requestCode == REQ_2){
                    FileInputStream fis = null;
                   try {
                       fis = new FileInputStream(storePath);
                       Bitmap bitmap = BitmapFactory.decodeStream(fis);
                       imageView.setImageBitmap(bitmap);
                   } catch (FileNotFoundException e) {
                       e.printStackTrace();
                   }finally {
                       try {
                           fis.close();
                       } catch (IOException e) {
                           e.printStackTrace();
                       }
                   }
                }
            }
        }
    
    }

[20190902091953267.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/17/162fc98785094170a2e678a42e3a53bb.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzIxNDgwNjA3_size_16_color_FFFFFF_t_70]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/17/aa8ee553172a44618d67c74f8880a000.png