从相机捕获照片+从图库中选择图像，并将其设置为布局或imageview的背景。下面是示例代码。

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;

    import android.provider.MediaStore;
    import android.util.Log;
    import android.view.View;
    import android.view.View.OnClickListener;
    import android.widget.AdapterView;
    import android.widget.AdapterView.OnItemClickListener;
    import android.widget.GridView;
    import android.widget.ImageView;
    import android.widget.LinearLayout;

    public class Post_activity extends Activity
    {
        final int TAKE_PICTURE = 1;
        final int ACTIVITY_SELECT_IMAGE = 2;

        ImageView openCameraOrGalleryBtn,cancelBtn;
        LinearLayout backGroundImageLinearLayout;

        public void onCreate(Bundle savedBundleInstance) {
            super.onCreate(savedBundleInstance);
            overridePendingTransition(R.anim.slide_up,0);
            setContentView(R.layout.post_activity);

            backGroundImageLinearLayout=(LinearLayout)findViewById(R.id.background_image_linear_layout);
            cancelBtn=(ImageView)findViewById(R.id.cancel_icon);

            openCameraOrGalleryBtn=(ImageView)findViewById(R.id.camera_icon);



            openCameraOrGalleryBtn.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub

                    selectImage();
                }
            });
            cancelBtn.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub
                overridePendingTransition(R.anim.slide_down,0);
                finish();
                }
            });

        }

    public void selectImage()
        {
             final CharSequence[] options = { "Take Photo", "Choose from Gallery","Cancel" };
             AlertDialog.Builder builder = new AlertDialog.Builder(Post_activity.this);
                builder.setTitle("Add Photo!");
                builder.setItems(options,new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        // TODO Auto-generated method stub
                        if(options[which].equals("Take Photo"))
                        {
                            Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE); 
                            startActivityForResult(cameraIntent, TAKE_PICTURE);
                        }
                        else if(options[which].equals("Choose from Gallery"))
                        {
                            Intent intent=new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                            startActivityForResult(intent, ACTIVITY_SELECT_IMAGE);
                        }
                        else if(options[which].equals("Cancel"))
                        {
                            dialog.dismiss();
                        }

                    }
                });
                builder.show();
        }
        public void onActivityResult(int requestcode,int resultcode,Intent intent)
        {
            super.onActivityResult(requestcode, resultcode, intent);
            if(resultcode==RESULT_OK)
            {
                if(requestcode==TAKE_PICTURE)
                {
                    Bitmap photo = (Bitmap)intent.getExtras().get("data"); 
                    Drawable drawable=new BitmapDrawable(photo);
                    backGroundImageLinearLayout.setBackgroundDrawable(drawable);

                }
                else if(requestcode==ACTIVITY_SELECT_IMAGE)
                {
                    Uri selectedImage = intent.getData();
                    String[] filePath = { MediaStore.Images.Media.DATA };
                    Cursor c = getContentResolver().query(selectedImage,filePath, null, null, null);
                    c.moveToFirst();
                    int columnIndex = c.getColumnIndex(filePath[0]);
                    String picturePath = c.getString(columnIndex);
                    c.close();
                    Bitmap thumbnail = (BitmapFactory.decodeFile(picturePath));
                    Drawable drawable=new BitmapDrawable(thumbnail);
                    backGroundImageLinearLayout.setBackgroundDrawable(drawable);


                }
            }
        }

        public void onBackPressed() {
            super.onBackPressed();
            //overridePendingTransition(R.anim.slide_down,0);
        }
    }

Add these permission in Androidmenifest.xml file

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

你得好好研究一下相机。(我认为要做到你想要的，你必须保存当前的图像到你的应用程序，在那里做选择/删除，然后召回相机再试一次，而不是直接在相机内部重试。)

2021年5月，爪哇

在处理了本文旁边所述的必要权限后， 在manifest中添加:

<uses-permission 
    android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission 
    android:name="android.permission.WRITE_EXTERNAL_STORAGE"
    android:maxSdkVersion="18"  />
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature
    android:name="android.hardware.camera"
    android:required="true" />
....

    <provider
        android:name="androidx.core.content.FileProvider"
        android:authorities="${applicationId}.fileprovider"
        android:exported="false"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/provider_paths" />
    </provider>
....

其中${applicationId}是应用程序的包名，例如my.app.com。

在res - > xml > provider_paths.xml

<?xml version="1.0" encoding="utf-8"?>
 <paths>
  <external-files-path name="my_images" path="Pictures" />
  <external-path name="external_files" path="."/>
    <files-path
    name="files"   path="." />
    <external-cache-path
      name="images" path="." />
 </paths>

在活动:

private void onClickCaptureButton(View view) {
    Intent takePictureIntent_ = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    // Ensure that there's a camera activity to handle the intent
    if (takePictureIntent_.resolveActivity(getPackageManager()) != null) {
        // Create the File where the photo should go
        File photoFile_ = null;
        try {
            photoFile_ = createImageFile();
        } catch (IOException ex) {
        }
        if(photoFile_!=null){
            picturePath=photoFile_.getAbsolutePath();
        }
        // Continue only if the File was successfully created
        if (photoFile_ != null) {
            Uri photoURI_ = FileProvider.getUriForFile(this,
               "my.app.com.fileprovider", photoFile_);
            takePictureIntent_.putExtra(MediaStore.EXTRA_OUTPUT, photoURI_);
            startActivityForResult(takePictureIntent_, REQUEST_IMAGE_CAPTURE);
        }
    }
}

还有三招:

...
private static String picturePath;
private static final int REQUEST_IMAGE_CAPTURE = 2;
...
private File createImageFile() throws IOException {
    // Create an image file name
    String timeStamp_ = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new 
      Date());
    String imageFileName_ = "JPEG_" + timeStamp_ + "_";
    File storageDir_ = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
    File image_ = File.createTempFile(
            imageFileName_,  /* prefix */
            ".jpg",         /* suffix */
            storageDir_      /* directory */
    );

    // Save a file: path for use with ACTION_VIEW intents
    picturePath= image_.getAbsolutePath();
    return image_;
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
   if(requestCode == REQUEST_IMAGE_CAPTURE && resultCode == Activity.RESULT_OK 
   ){

        try {
            File file_ = new File(picturePath);
            Uri uri_ = FileProvider.getUriForFile(this,
                    "my.app.com.fileprovider", file_);
            rasm.setImageURI(uri_);
        } catch (/*IO*/Exception e) {
            e.printStackTrace();
        }
    }
}

and

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
    savedInstanceState.putString("safar", picturePath);
    // Always call the superclass so it can save the view hierarchy state
    super.onSaveInstanceState(savedInstanceState);
}

and:

 @Override
 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    if (savedInstanceState != null) {
        picturePath = savedInstanceState.getString("safar");
    }
 ....
}

您可以使用自定义相机与缩略图图像。 你可以看看我的项目。

以下是完整的代码:

package com.example.cameraa;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

public class MainActivity extends Activity {




        Button btnTackPic;
        Uri photoPath;
        ImageView ivThumbnailPhoto;

        static int TAKE_PICTURE = 1;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);

            // Get reference to views

            btnTackPic = (Button) findViewById(R.id.bt1);
            ivThumbnailPhoto = (ImageView) findViewById(R.id.imageView1);




     btnTackPic.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub


                Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE); 
                startActivityForResult(cameraIntent, TAKE_PICTURE); 
            }




    });

        } 

        @Override
        protected void onActivityResult(int requestCode, int resultCode, Intent intent) {


                if (requestCode == TAKE_PICTURE && resultCode == RESULT_OK) {  
                    Bitmap photo = (Bitmap)intent.getExtras().get("data"); 
                   ivThumbnailPhoto.setImageBitmap(photo);
                ivThumbnailPhoto.setVisibility(View.VISIBLE);



            }
        }
}

记住也要为相机添加权限。

下面是一个示例活动，它将启动相机应用程序，然后检索图像并显示它。

package edu.gvsu.cis.masl.camerademo;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

public class MyCameraActivity extends Activity
{
    private static final int CAMERA_REQUEST = 1888; 
    private ImageView imageView;
    private static final int MY_CAMERA_PERMISSION_CODE = 100;

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        this.imageView = (ImageView)this.findViewById(R.id.imageView1);
        Button photoButton = (Button) this.findViewById(R.id.button1);
        photoButton.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                if (checkSelfPermission(Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED)
                {
                    requestPermissions(new String[]{Manifest.permission.CAMERA}, MY_CAMERA_PERMISSION_CODE);
                }
                else
                {
                    Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE); 
                    startActivityForResult(cameraIntent, CAMERA_REQUEST);
                } 
            }
        });
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults)
    {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == MY_CAMERA_PERMISSION_CODE)
        {
            if (grantResults[0] == PackageManager.PERMISSION_GRANTED)
            {
                Toast.makeText(this, "camera permission granted", Toast.LENGTH_LONG).show();
                Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE); 
                startActivityForResult(cameraIntent, CAMERA_REQUEST);
            }
            else
            {
                Toast.makeText(this, "camera permission denied", Toast.LENGTH_LONG).show();
            }
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data)
    {  
        if (requestCode == CAMERA_REQUEST && resultCode == Activity.RESULT_OK)
        {  
            Bitmap photo = (Bitmap) data.getExtras().get("data"); 
            imageView.setImageBitmap(photo);
        }  
    } 
}

请注意，相机应用程序本身提供了查看/重拍图像的功能，一旦图像被接受，活动就会显示它。

下面是上面的活动使用的布局。它只是一个包含id为button1的Button和id为imageview1的ImageView的LinearLayout:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    <Button android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/photo"></Button>
    <ImageView android:id="@+id/imageView1" android:layout_height="wrap_content" android:src="@drawable/icon" android:layout_width="wrap_content"></ImageView>

</LinearLayout>

最后一个细节，一定要加上:

<uses-feature android:name="android.hardware.camera"></uses-feature> 

如果摄像头是你应用功能的可选选项。请确保在权限中将require设置为false。像这样

<uses-feature android:name="android.hardware.camera" android:required="false"></uses-feature>

到你的manifest.xml。