Android官方Training学习——Multimedia多媒体

最新推荐文章于 2024-06-06 16:33:34 发布

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本文详细介绍了如何在Android应用中实现拍照与录制视频的功能。包括配置相机权限、启动相机进行拍照、保存图片到本地及添加到相册、调整图片显示大小、启动录像功能并在VideoView中播放等步骤。

1.捕获照片

1.简单的拍照

获取权限

<manifest ... >
    <uses-feature android:name="android.hardware.camera"
                  android:required="true" />			//设为true，设备必须拥有相机才能安装应用
    ...							//使用 hasSystemFeature(PackageManager.FEATURE_CAMERA)检测相机是否可用
</manifest>

用相机拍个照片

static final int REQUEST_IMAGE_CAPTURE = 1;				//定义请求代码

private void dispatchTakePictureIntent() {
    Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    if (takePictureIntent.resolveActivity(getPackageManager()) != null) {	//检测有无可相应Intent的程序
        startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);	//拍照
    }
}

获得小样

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {
        Bundle extras = data.getExtras();
        Bitmap imageBitmap = (Bitmap) extras.get("data");		//系统自动保存一个小尺寸的图片，key值是"data"
        mImageView.setImageBitmap(imageBitmap);
    }
}

保存完整图片

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

String mCurrentPhotoPath;

private File createImageFile() throws IOException {
    // Create an image file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());	//定义文件名
    String imageFileName = "JPEG_" + timeStamp + "_";
    File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);		//获得存储目录
    File image = File.createTempFile(							//创建临时目录
        imageFileName,  /* prefix */
        ".jpg",         /* suffix */
        storageDir      /* directory */
    );

    // Save a file: path for use with ACTION_VIEW intents
    mCurrentPhotoPath = image.getAbsolutePath();					//保存绝对目录
    return image;
}

创建虚拟文件保存并获得Uri

private void dispatchTakePictureIntent() {
    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) {
            // Error occurred while creating the File
            ...
        }
        // Continue only if the File was successfully created
        if (photoFile != null) {
            Uri photoURI = FileProvider.getUriForFile(this,
                                                  "com.example.android.fileprovider",
                                                  photoFile);
            takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
            startActivityForResult(takePictureIntent, REQUEST_TAKE_PHOTO);
        }
    }
}

添加进画廊公开图片

private void galleryAddPic() {
    Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
    File f = new File(mCurrentPhotoPath);
    Uri contentUri = Uri.fromFile(f);
    mediaScanIntent.setData(contentUri);
    this.sendBroadcast(mediaScanIntent);
}

设置图片到View

private void setPic(){
        int targetW = mImageView.getWidth();
        int targetH = mImageView.getHeight();

        BitmapFactory.Options bmOptions = new BitmapFactory.Options();
        bmOptions.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(mCurrentPhotoPath,bmOptions);
        int photoW = bmOptions.outWidth;
        int photoH = bmOptions.outHeight;
        int scaleFactor = Math.min(photoW/targetW,photoH/targetH);
        bmOptions.inJustDecodeBounds = false;
        bmOptions.inSampleSize = scaleFactor;
        bmOptions.inPurgeable = true;

        Bitmap bitmap = BitmapFactory.decodeFile(mCurrentPhotoPath,bmOptions);
        mImageView.setImageBitmap(bitmap);
    }

2.简单的拍视频

简单的定义Intent

private void dispatchTakeVideoIntent() {
        Intent videoIntent = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
        if(videoIntent.resolveActivity(getPackageManager())!=null){
            startActivityForResult(videoIntent,REQUEST_VIDEO_CAPTURE);
        }
    }

简单的在VideoView播放

 if(requestCode == REQUEST_VIDEO_CAPTURE && resultCode == Activity.RESULT_OK){
            Uri videoUri = data.getData();
            mVideoView.setVideoURI(videoUri);
        }