拍摄照片和视频

在Android多媒体开发中我们最常用的就是照片、视频的拍摄。其实在开发中我们不会自己去写一个照相机、摄像机程序，而是去调用系统中已经存在的照相、摄影程序；

拍摄照片

1：布局

<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"
>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/bt_takepicture"
android:text="拍照"
android:textSize="20sp"
/>
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"
android:id="@+id/iv_showimage"
/>
</LinearLayout>

2、Activity

package com.example.takethepicture;
import java.io.File;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

public class MainActivity extends Activity {

private static final int REQUEST_IMAGE = 0x100;
private Button bt_take;
private ImageView iv_picture;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bt_take = (Button) this.findViewById(R.id.bt_takepicture);
iv_picture = (ImageView) this.findViewById(R.id.iv_showimage);
bt_take.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, REQUEST_IMAGE);
}
});
}

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

switch (requestCode) {
case REQUEST_IMAGE:
if(Activity.RESULT_OK == resultCode){
//我们直接从Intent中获取我们的Bitmap
Bitmap image = (Bitmap) data.getExtras().get("data");
iv_picture.setImageBitmap(image);
}
break;
}
}
}

有时我们需要将我们的拍摄的照片先保存到外存，我们可以在Intent 的MediaStore.EXTRA_

OUTPUT 中放入照片保存位置的URI。

intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(imagePath));

更改我们的Activity：

package com.example.takethepicture;

import java.io.File;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

public class MainActivity extends Activity {

private static final int REQUEST_IMAGE = 0x100;
private Button bt_take;
private ImageView iv_picture;
private File imagePath;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bt_take = (Button) this.findViewById(R.id.bt_takepicture);
iv_picture = (ImageView) this.findViewById(R.id.iv_showimage);
imagePath = new File(Environment.getExternalStorageDirectory(),"myimage.jpg");
bt_take.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(imagePath));
startActivityForResult(intent, REQUEST_IMAGE);
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {

switch (requestCode) {
case REQUEST_IMAGE:
if(Activity.RESULT_OK == resultCode){
Toast.makeText(MainActivity.this, imagePath.getAbsolutePath(), Toast.LENGTH_LONG).show();
//为了避免将全尺寸的Bitmap加载到内存中，需要图片在屏幕上显示之前，通过BitmapFactory.Options对图片进行缩放
BitmapFactory.Options opts = new BitmapFactory.Options();
opts.inSampleSize = 10;
Bitmap image = BitmapFactory.decodeFile(imagePath.getAbsolutePath(), opts);
iv_picture.setImageBitmap(image);
}
break;
}
}
}

添加权限：

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

下面的Demo是我们通过上面的Button录制视频，下面可以通过VideoView观看我们的录制的视频。

拍摄视频

真正的视频片段数据是不会通过Intent的附加数据返回的，通常我们都是保存到一个指定的文件中，以下两个参数可能会作为附加数据添加到Intent中：

(1) MediaStore.EXTRA_VIDEO_QUALITY

a.整型值，用来描述拍摄的视频的质量等级。

b. 0 表示低质量，1 表示高质量

(2) MediaStore.EXTRA_OUTPUT

c.保存视频内容的Uri

d. 如果没有指定保存位置，视频则会保存到设备的标准位置中。

视频录制结束后，会在结果Intent 的data 中返回视频数据真正存储位置的Uri,我们通过Uri可以通过VideoView.setVideoURI(data.getData());来播放我们的视频；

1：布局

<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"
>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="拍摄视频"
android:id="@+id/bt_video"
/>
<VideoView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/videoView"
/>
</LinearLayout>

2、Activity

package com.example.takevideo;
import java.io.File;
import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.MediaController;
import android.widget.Toast;
import android.widget.VideoView;

public class MainActivity extends Activity {

private static final int REQUEST_VIDEO = 0x100;
private Button button;
private VideoView videoView;
private MediaController mediaController;
private File videoPath;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mediaController = new MediaController(MainActivity.this);
button = (Button) this.findViewById(R.id.bt_video);
videoView = (VideoView) this.findViewById(R.id.videoView);
videoPath = new File(Environment.getExternalStorageDirectory(),"myVideo");
button.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(videoPath));
intent.putExtra(MediaStore.EXTRA_VIDEO_QUALITY, 0);
startActivityForResult(intent, REQUEST_VIDEO);
}
});
}

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

switch (requestCode) {
case REQUEST_VIDEO:
if(Activity.RESULT_OK == resultCode){
Toast.makeText(MainActivity.this, videoPath.getAbsolutePath(), Toast.LENGTH_LONG).show();
if(videoPath.exists()){
videoView.setVideoPath(videoPath.getAbsolutePath());
videoView.setMediaController(mediaController);
mediaController.setMediaPlayer(videoView);
videoView.requestFocus();
}
//videoView.setVideoURI(data.getData());
}
break;
}
}
}

3、添加权限

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

对于如何将VideoView与MediaController进行联系，请读者自己查资料吧！在这里不做讲解了！