android模拟照相机

package com.youga.capturingphotos; import android.Manifest; import android.app.Activity; import android.content.ContentResolver; import android.content.Context; import android.content.Intent; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.net.Uri; import android.os.Build; import android.os.Environment; import android.provider.MediaStore; import android.support.v4.content.ContextCompat; import android.support.v4.content.FileProvider; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.util.Log; import android.view.View; import android.widget.Button; import android.widget.ImageView; import java.io.File; import java.io.IOException; import java.text.SimpleDateFormat; import java.util.Date; import java.util.Locale; public class MainActivity extends AppCompatActivity { private static final int REQ_THUMB = 222; private static final int REQ_GALLERY = 333; private static final String TAG = "MainActivity"; private static final int REQ_TAKE_PHOTO = 444; Button mThumbnail, mFullSize, mAddGallery; ImageView mImageView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); init(); } private void init() { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) { requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 200); } mThumbnail = (Button) findViewById(R.id.thumbnail); mFullSize = (Button) findViewById(R.id.fullSize); mAddGallery = (Button) findViewById(R.id.addGallery); mImageView = (ImageView) findViewById(R.id.imageView); mThumbnail.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); if (takePictureIntent.resolveActivity(getPackageManager()) != null) {//判断是否有相机应用 startActivityForResult(takePictureIntent, REQ_THUMB); } } }); mFullSize.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); // Ensure that there's a camera activity to handle the intent if (takePictureIntent.resolveActivity(getPackageManager()) != null) {//判断是否有相机应用 // Create the File where the photo should go File photoFile = null; try { photoFile = createImageFile();//创建临时图片文件 } catch (IOException ex) { ex.printStackTrace(); } // Continue only if the File was successfully created if (photoFile != null) { //FileProvider 是一个特殊的 ContentProvider 的子类， //它使用 content:// Uri 代替了 file:/// Uri. ，更便利而且安全的为另一个app分享文件 Uri photoURI = FileProvider.getUriForFile(MainActivity.this, "com.youga.fileprovider", photoFile); Log.i(TAG, "photoURI:" + photoURI.toString()); takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI); startActivityForResult(takePictureIntent, REQ_TAKE_PHOTO); } } } }); mAddGallery.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); // Ensure that there's a camera activity to handle the intent if (takePictureIntent.resolveActivity(getPackageManager()) != null) {//判断是否有相机应用 // Create the File where the photo should go File photoFile = null; try { photoFile = createPublicImageFile();//创建临时图片文件 } catch (IOException ex) { ex.printStackTrace(); } // Continue only if the File was successfully created if (photoFile != null) { Uri photoURI = FileProvider.getUriForFile(MainActivity.this, "com.youga.fileprovider", photoFile); takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI); startActivityForResult(takePictureIntent, REQ_GALLERY); } } galleryAddPic(); } }); } String mCurrentPhotoPath; private File createImageFile() throws IOException { // Create an image file name String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss", Locale.CHINA).format(new Date()); String imageFileName = "JPEG_" + timeStamp + "_"; //.getExternalFilesDir()方法可以获取到 SDCard/Android/data/你的应用的包名/files/ 目录，一般放一些长时间保存的数据 File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES); //创建临时文件,文件前缀不能少于三个字符,后缀如果为空默认未".tmp" File image = File.createTempFile( imageFileName, /* 前缀 */ ".jpg", /* 后缀 */ storageDir /* 文件夹 */ ); mCurrentPhotoPath = image.getAbsolutePath(); return image; } String mPublicPhotoPath; private File createPublicImageFile() throws IOException { File path = Environment.getExternalStoragePublicDirectory( Environment.DIRECTORY_DCIM); // Create an image file name Log.i(TAG, "path:" + path.getAbsolutePath()); String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss", Locale.CHINA).format(new Date()); String imageFileName = "JPEG_" + timeStamp; File image = File.createTempFile( imageFileName, /* 前缀 */ ".jpg", /* 后缀 */ path /* 文件夹 */ ); mPublicPhotoPath = image.getAbsolutePath(); return image; } private void galleryAddPic() { Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE); File f = new File(mPublicPhotoPath); Uri contentUri = Uri.fromFile(f); mediaScanIntent.setData(contentUri); sendBroadcast(mediaScanIntent); } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); switch (requestCode) { case REQ_THUMB://返回结果 if (resultCode != Activity.RESULT_OK) return; Bundle extras = data.getExtras(); Bitmap imageBitmap = (Bitmap) extras.get("data"); mImageView.setImageBitmap(imageBitmap); break; case REQ_TAKE_PHOTO://返回结果 if (resultCode != Activity.RESULT_OK) return; // Get the dimensions of the View int targetW = mImageView.getWidth(); int targetH = mImageView.getHeight(); // Get the dimensions of the bitmap BitmapFactory.Options bmOptions = new BitmapFactory.Options(); bmOptions.inJustDecodeBounds = true; BitmapFactory.decodeFile(mCurre