android实现拍照或从相册选取图片

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
 android:orientation="vertical"
 android:padding="16dp"
 tools:context=".MainActivity">
 
 <LinearLayout
 android:layout_width="match_parent"
 android:layout_height="wrap_content">
 
 <Button
 android:id="@+id/btn_photo"
 android:layout_width="0dp"
 android:layout_height="wrap_content"
 android:layout_weight="1"
 android:background="@android:color/holo_red_light"
 android:text="相册选取"
 android:textColor="#FFF"
 android:textSize="16sp" />
 
 <Button
 android:id="@+id/btn_camera"
 android:layout_width="0dp"
 android:layout_height="wrap_content"
 android:layout_marginLeft="16dp"
 android:layout_weight="1"
 android:background="@android:color/holo_red_light"
 android:text="拍照"
 android:textColor="#FFF"
 android:textSize="16sp" />
 </LinearLayout>
 
 <!--展示选择的图片-->
 <ImageView
 android:id="@+id/image_show"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:layout_gravity="center_horizontal"
 android:layout_margin="6dp" />
 
</LinearLayout>

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

**
 * 拍照 或 从相册获取图片
 */
public class MainActivity extends AppCompatActivity {
 private Button btn_camera;
 private ImageView imageView;
 
 public static final int TAKE_CAMERA = 101;
 private Uri imageUri;
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 
 btn_camera = (Button) findViewById(R.id.btn_camera);
 imageView = (ImageView) findViewById(R.id.image_show);
 
 //通过摄像头拍照
 btn_camera.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 // 创建File对象，用于存储拍照后的图片
 //存放在手机SD卡的应用关联缓存目录下
 File outputImage = new File(getExternalCacheDir(), "output_image.jpg");
 
 try {
 if (outputImage.exists()) {
 outputImage.delete();
 }
 } catch (Exception e) {
 e.printStackTrace();
 }
 
 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
 //大于等于版本24（7.0）的场合
 imageUri = FileProvider.getUriForFile(MainActivity.this, "com.feige.pickphoto.fileprovider", outputImage);
 } else {
 //小于android 版本7.0（24）的场合
 imageUri = Uri.fromFile(outputImage);
 }
 
 //启动相机程序
 Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
 //MediaStore.ACTION_IMAGE_CAPTURE = android.media.action.IMAGE_CAPTURE
 intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
 startActivityForResult(intent, TAKE_CAMERA);
 
 }
 });
 
 @Override
 protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
 switch (requestCode) {
 case TAKE_CAMERA:
 if (resultCode == RESULT_OK) {
 try {
 // 将拍摄的照片显示出来
 Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageUri));
 imageView.setImageBitmap(bitmap);
 } catch (FileNotFoundException e) {
 e.printStackTrace();
 }
 }
 break;
 default:
 break;
 }
 }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
 package="com.feige.pickphoto">
 
 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 
 <application
 android:allowBackup="true"
 android:icon="@mipmap/ic_launcher"
 android:label="@string/app_name"
 android:roundIcon="@mipmap/ic_launcher_round"
 android:supportsRtl="true"
 android:theme="@style/AppTheme">
 <activity android:name=".MainActivity">
 <intent-filter>
 <action android:name="android.intent.action.MAIN" />
 
 <cateGory android:name="android.intent.category.LAUNCHER" />
 </intent-filter>
 </activity>
 
 <provider
 android:name="android.support.v4.content.FileProvider"
 android:authorities="com.feige.pickphoto.fileprovider"
 android:exported="false"
 android:grantUriPermissions="true">
 <meta-data
 android:name="android.support.FILE_PROVIDER_PATHS"
 android:resource="@xml/file_paths" />
 </provider>
 
 </application>
 
</manifest>

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
 <!--external-path 就是用来指定Uri 共享的，
 name 属性的值可以随便填， path 属性的 值表示共享的具体路径。
 这里设置 . 就表示将整个SD卡进行共享 -->
 <external-path
 name="my_images"
 path="." />
</paths>

public class MainActivity extends AppCompatActivity {
 private Button choose_photo;
 private ImageView imageView;
 
 public static final int PICK_PHOTO = 102;
 private Uri imageUri;
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 
 choose_photo = (Button) findViewById(R.id.btn_photo);
 imageView = (ImageView) findViewById(R.id.image_show); 
 
 //从相册选择图片
 choose_photo.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 //动态申请获取访问 读写磁盘的权限
 if (ContextCompat.checkSelfPermission(MainActivity.this,
 Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
 ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 101);
 } else {
 //打开相册
 Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
 //Intent.ACTION_GET_CONTENT = "android.intent.action.GET_CONTENT"
 intent.setType("image
 private void handleImageBeforeKitKat(Intent data) {
 Uri uri = data.getData();
 String imagePath = getImagePath(uri, null);
 displayImage(imagePath);
 }
 
 private String getImagePath(Uri uri, String selection) {
 String path = null;
 // 通过Uri和selection来获取真实的图片路径
 Cursor cursor = getContentResolver().query(uri, null, selection, null, null);
 if (cursor != null) {
 if (cursor.moveToFirst()) {
 path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
 }
 cursor.close();
 }
 return path;
 }
 
 private void displayImage(String imagePath) {
 if (imagePath != null) {
 Bitmap bitmap = BitmapFactory.decodeFile(imagePath);
 imageView.setImageBitmap(bitmap);
 } else {
 Toast.makeText(this, "获取相册图片失败", Toast.LENGTH_SHORT).show();
 }
 }
 
}

import android.Manifest;
import android.annotation.Targetapi;
import android.content.ContentUris;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Build;
import android.provider.DocumentsContract;
import android.provider.MediaStore;
import android.support.annotation.Nullable;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v4.content.FileProvider;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
 
import java.io.File;
import java.io.FileNotFoundException;
 

public class MainActivity extends AppCompatActivity {
 private Button choose_photo;
 private Button btn_camera;
 private ImageView imageView;
 
 public static final int TAKE_CAMERA = 101;
 public static final int PICK_PHOTO = 102;
 private Uri imageUri;
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 
 choose_photo = (Button) findViewById(R.id.btn_photo);
 btn_camera = (Button) findViewById(R.id.btn_camera);
 imageView = (ImageView) findViewById(R.id.image_show);
 
 //通过摄像头拍照
 btn_camera.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 // 创建File对象，用于存储拍照后的图片
 //存放在手机SD卡的应用关联缓存目录下
 File outputImage = new File(getExternalCacheDir(), "output_image.jpg");
 
 try {
 if (outputImage.exists()) {
 outputImage.delete();
 }
 } catch (Exception e) {
 e.printStackTrace();
 }
 
 
 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
 //大于等于版本24（7.0）的场合
 imageUri = FileProvider.getUriForFile(MainActivity.this, "com.feige.pickphoto.fileprovider", outputImage);
 } else {
 //小于android 版本7.0（24）的场合
 imageUri = Uri.fromFile(outputImage);
 }
 
 //启动相机程序
 Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
 //MediaStore.ACTION_IMAGE_CAPTURE = android.media.action.IMAGE_CAPTURE
 intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
 startActivityForResult(intent, TAKE_CAMERA);
 
 }
 });
 
 //从相册选择图片
 choose_photo.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 //动态申请获取访问 读写磁盘的权限
 if (ContextCompat.checkSelfPermission(MainActivity.this,
 Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
 ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 101);
 } else {
 //打开相册
 Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
 //Intent.ACTION_GET_CONTENT = "android.intent.action.GET_CONTENT"
 intent.setType("image
 private void handleImageBeforeKitKat(Intent data) {
 Uri uri = data.getData();
 String imagePath = getImagePath(uri, null);
 displayImage(imagePath);
 }
 
 private String getImagePath(Uri uri, String selection) {
 String path = null;
 // 通过Uri和selection来获取真实的图片路径
 Cursor cursor = getContentResolver().query(uri, null, selection, null, null);
 if (cursor != null) {
 if (cursor.moveToFirst()) {
 path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
 }
 cursor.close();
 }
 return path;
 }
 
 private void displayImage(String imagePath) {
 if (imagePath != null) {
 Bitmap bitmap = BitmapFactory.decodeFile(imagePath);
 imageView.setImageBitmap(bitmap);
 } else {
 Toast.makeText(this, "获取图片失败", Toast.LENGTH_SHORT).show();
 }
 }
 
}