Android中实现拍照有两种方法,一种是调用系统自带的相机,然后使用其返回的照片数据。 还有一种是自己用Camera类和其他相关类实现相机功能,这种方法定制度比较高,比较复杂,一般平常的应用只需使用第一种即可。
用Intent启动相机的代码:
- Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
- startActivityForResult(intent, 1);
要将图像存储到SD卡上之前,最好检查一下SD卡是否可用
- String sdStatus = Environment.getExternalStorageState();
- if (!sdStatus.equals(Environment.MEDIA_MOUNTED)) { // 检测sd是否可用
- Log.v("TestFile",
- "SD card is not available/writeable right now.");
- return;
- }
另外,要注意的是读写SD卡必须在Mainifest.xml文件中配置权限:
- <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
- <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
一个示例如下:
MainActivity.java:
- package com.example.testand;
- import java.io.File;
- import java.io.FileNotFoundException;
- import java.io.FileOutputStream;
- import java.io.IOException;
- import android.os.Bundle;
- import android.os.Environment;
- import android.provider.MediaStore;
- import android.app.Activity;
- import android.content.Intent;
- import android.graphics.Bitmap;
- import android.util.Log;
- import android.view.Menu;
- import android.view.View;
- import android.view.View.OnClickListener;
- import android.widget.Button;
- import android.widget.ImageView;
- public class MainActivity extends Activity {
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.activity_main);
- Button button=(Button) findViewById(R.id.button);
- button.setOnClickListener(new OnClickListener(){
- @Override
- public void onClick(View v) {
- Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
- startActivityForResult(intent, 1);
- }
- });
- }
- protected void onActivityResult(int requestCode, int resultCode, Intent data){
- super.onActivityResult(requestCode, resultCode, data);
- String sdStatus = Environment.getExternalStorageState();
- if (!sdStatus.equals(Environment.MEDIA_MOUNTED)) { // 检测sd是否可用
- Log.v("TestFile","SD card is not avaiable/writeable right now.");
- return;
- }
- Bundle bundle = data.getExtras();
- Bitmap bitmap = (Bitmap) bundle.get("data");// 获取相机返回的数据,并转换为Bitmap图片格式
- File file = new File("/sdcard/myImage/");
- FileOutputStream bout = null;
- file.mkdirs();// 创建文件夹
- String fileName = "/sdcard/myImage/111.jpg";
- try {
- bout = new FileOutputStream(fileName);
- bitmap.compress(Bitmap.CompressFormat.JPEG, 100, bout);// 把数据写入文件
- } catch (FileNotFoundException e) {
- e.printStackTrace();
- } finally {
- try {
- bout.flush();
- bout.close();
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
- ((ImageView) findViewById(R.id.imageView)).setImageBitmap(bitmap);// 将图片显示在ImageView里
- }
- @Override
- public boolean onCreateOptionsMenu(Menu menu) {
- // Inflate the menu; this adds items to the action bar if it is present.
- getMenuInflater().inflate(R.menu.main, menu);
- return true;
- }
- }
activity_main.xml:
- <RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
- android:paddingLeft="@dimen/activity_horizontal_margin"
- android:paddingRight="@dimen/activity_horizontal_margin"
- android:paddingTop="@dimen/activity_vertical_margin"
- tools:context=".MainActivity" >
- <Button
- android:id="@+id/button"
- android:layout_width="fill_parent"
- android:layout_height="wrap_content"
- android:text="点击启动相机" />
- <ImageView
- android:id="@+id/imageView"
- android:layout_width="fill_parent"
- android:layout_height="wrap_content"
- android:layout_alignLeft="@+id/button"
- android:layout_alignParentBottom="true"
- android:layout_below="@+id/button"
- android:background="#999999" />
- </RelativeLayout>
AndroidManifest.xml:
- <?xml version="1.0" encoding="utf-8"?>
- <manifest xmlns:android="http://schemas.android.com/apk/res/android"
- package="com.example.testand"
- android:versionCode="1"
- android:versionName="1.0" >
- <uses-sdk
- android:minSdkVersion="8"
- android:targetSdkVersion="18" />
- <application
- android:allowBackup="true"
- android:icon="@drawable/ic_launcher"
- android:label="@string/app_name"
- android:theme="@style/AppTheme" >
- <activity
- android:name="com.example.testand.MainActivity"
- android:label="@string/app_name" >
- <intent-filter>
- <action android:name="android.intent.action.MAIN" />
- <category android:name="android.intent.category.LAUNCHER" />
- </intent-filter>
- </activity>