Android调用摄像头拍照开发教程

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:tools="http://schemas.android.com/tools"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:orientation="vertical"  tools:context="com.gyq.cameraalbumtest.MainActivity">  <Button    android:id="@+id/btn_take_photo"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:text="take photo"/>  <Button    android:id="@+id/choose_from_album"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:text="choose from album"/>  <ImageView    android:id="@+id/iv_picture"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_gravity="center_horizontal"/></LinearLayout>

package com.gyq.cameraalbumtest;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.os.Bundle;import android.provider.DocumentsContract;import android.provider.MediaStore;import android.support.annotation.NonNull;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.view.View;import android.widget.Button;import android.widget.ImageView;import android.widget.Toast;import java.io.File;public class MainActivity extends AppCompatActivity {  public static final int TAKE_PHOTO = 1;  public static final int CHOOSE_PHOTO = 2;  private Button mTakePhoto, mChoosePhoto;  private ImageView picture;  private Uri imageUri;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    mTakePhoto = (Button) findViewById(R.id.btn_take_photo);    mChoosePhoto = (Button) findViewById(R.id.choose_from_album);    picture = (ImageView) findViewById(R.id.iv_picture);    mTakePhoto.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；        File outputImage = new File(getExternalCacheDir(), "output_image.jpg");        try {          if (outputImage.exists()) {            outputImage.delete();          }          outputImage.createNewFile();        } catch (Exception e) {          e.printStackTrace();        }        if (Build.VERSION.SDK_INT >= 24) {          imageUri = FileProvider.getUriForFile(MainActivity.this,              "com.gyq.cameraalbumtest.fileprovider", outputImage);        } else {          imageUri = Uri.fromFile(outputImage);        }        //启动相机程序        Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");        intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);        startActivityForResult(intent, TAKE_PHOTO);      }    });    mChoosePhoto.setOnClickListener(new View.OnClickListener() {      @Override      public void onClick(View v) {        if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {          ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);        } else {          openAlbum();        }      }    });  }  //打开相册  private void openAlbum() {    Intent intent = new Intent("android.intent.action.GET_CONTENT");    intent.setType("image/*");    startActivityForResult(intent, CHOOSE_PHOTO);  }  @Override  public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {    switch (requestCode) {      case 1:        if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {          openAlbum();        } else {          Toast.makeText(this, "you denied the permission", Toast.LENGTH_SHORT).show();        }        break;    }  }  @Override  protected void onActivityResult(int requestCode, int resultCode, Intent data) {    switch (requestCode) {      case TAKE_PHOTO:        if (resultCode == RESULT_OK) {          try {            Bitmap bm = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageUri));            picture.setImageBitmap(bm);          } catch (Exception e) {            e.printStackTrace();          }        }        break;      case CHOOSE_PHOTO:        if (resultCode == RESULT_OK) {          if (Build.VERSION.SDK_INT >= 19) { //4.4及以上的系统使用这个方法处理图片；            handleImageOnKitKat(data);          } else {            handleImageBeforeKitKat(data); //4.4及以下的系统使用这个方法处理图片          }        }      default:        break;    }  }  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);      picture.setImageBitmap(bitmap);    } else {      Toast.makeText(this, "failed to get image", Toast.LENGTH_SHORT).show();    }  }  /**   * 4.4及以上的系统使用这个方法处理图片   *   * @param data   */  @TargetApi(19)  private void handleImageOnKitKat(Intent data) {    String imagePath = null;    Uri uri = data.getData();    if (DocumentsContract.isDocumentUri(this, uri)) {      //如果document类型的Uri,则通过document来处理      String docID = DocumentsContract.getDocumentId(uri);      if ("com.android.providers.media.documents".equals(uri.getAuthority())) {        String id = docID.split(":")[1];   //解析出数字格式的id        String selection = MediaStore.Images.Media._ID + "=" + id;        imagePath = getImagePath(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, selection);      } else if ("com.android.providers.downloads.documents".equals(uri.getAuthority())) {        Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/piblic_downloads"), Long.valueOf(docID));        imagePath = getImagePath(contentUri, null);      }    } else if ("content".equalsIgnoreCase(uri.getScheme())) {      //如果是content类型的uri，则使用普通方式使用      imagePath = getImagePath(uri, null);    } else if ("file".equalsIgnoreCase(uri.getScheme())) {      //如果是file类型的uri，直接获取路径即可      imagePath = uri.getPath();    }    displayImage(imagePath);  }}

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"  package="com.gyq.cameraalbumtest">  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>  <application    android:allowBackup="true"    android:icon="@mipmap/ic_launcher"    android:label="@string/app_name"    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:authorities="com.gyq.cameraalbumtest.fileprovider"      android:name="android.support.v4.content.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 name = "my_images" path = ""></external-path> </paths>