注意：android7.0与7.0以下版本获取相机拍照后的照片的路径的方式不同，具体代码在给我的github上，地址为https://github.com/liang1075963999/android7.0
例一：启动相机拍一张照片，然后将照片显示在imageview上，代码如下：
public class MainActivity extends AppCompatActivity {
private Button button;
private ImageView imageView;
private Uri imageuri;
public static final int TAKE_PHOTO=1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button) findViewById(R.id.button);
imageView = (ImageView) findViewById(R.id.imageView);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
File file=new File(getExternalCacheDir(),"1.jpg");
Log.i("xinxi",getExternalCacheDir()+"");//输出内容为：/storage/emulated/0/Android/data/com.example.liang.myapplication/cache
if(file.exists()){//exists的中文意思是存在
file.delete();
}
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
if(Build.VERSION.SDK_INT>=24)
{
imageuri= FileProvider.getUriForFile(MainActivity.this,"com.example.liang.myapplication",file);//得到文件的uri
Log.i("xinxi",imageuri.toString());
}
else {
imageuri=Uri.fromFile(file);//我的手机只会执行else里面的语句，说明我的手机的sdk的版本小于24，因为我的手机是android6.0，api是23，只有android7.0及以上版本才会执行以上的语句
Log.i("xinxi",imageuri.toString());//输出结果为：file:///storage/emulated/0/Android/data/com.example.liang.myapplication/cache/1.jpg
}
Intent intent=new Intent("android.media.action.IMAGE_CAPTURE");//启动相机的action是android.media.action.IMAGE_CAPTURE
intent.putExtra(MediaStore.EXTRA_OUTPUT,imageuri);//将照片的uri路径写入，照片就会保存在该路径下
startActivityForResult(intent,TAKE_PHOTO);//使用startActivityForResult启动的活动，在活动启动之后会给原来的活动返回一个结果码，这个结果码在onActivityResult方法中接收，来判断是否正常启动了
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
switch (requestCode){
case TAKE_PHOTO:
if(resultCode==RESULT_OK){
try {
Bitmap bitmap= BitmapFactory.decodeStream(getContentResolver().openInputStream(imageuri));//读出路径下图片的流，然后转换为bitmap
imageView.setImageBitmap(bitmap);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
break;
default:
}
}
}
因为android7.0中得到一个文件的uri涉及到了content provider，所以需要在androidmanifest中进行配置，内容如下：
device-2017-11-14-182630.png
例二：从相册中选择图片
public class MainActivity extends AppCompatActivity {
private Button button;
private ImageView imageView;
private static final int CHOOSE_PHOTO = 2;//这里之所以是2，是因为这个例子和例一其实是一起的，但是我给分开了，因为例一中的TAKE_PHOTO=1，所以这里要用2，加以区分
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button) findViewById(R.id.button);
imageView = (ImageView) findViewById(R.id.imageView);
button.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 {
qidong();
}
}
});
}
private void qidong() {
Intent intent = new Intent("android.intent.action.GET_CONTENT");//启动手机内容的action是android.intent.action.GET_CONTENT
intent.setType("image/*");//设置所需手机内容为图片
startActivityForResult(intent, CHOOSE_PHOTO);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
switch (requestCode) {
case CHOOSE_PHOTO:
if (resultCode == RESULT_OK) {
if (Build.VERSION.SDK_INT >= 19) {
//4.4.及以上版本使用这个方法处理图片
one(data);
} else {
//4.4.以下版本使用这个方法处理图片
another(data);
}
}
}
}
@TargetApi(19)
private void one(Intent intent) {
String imagepath = null;
Uri uri = intent.getData();
Log.i("xinxi", "intent.getData().toString()为：" + intent.getData().toString());
Log.i("xinxi", "uri.getAuthority()为：" + uri.getAuthority());
Log.i("xinxi", "uri.getScheme()为：" + uri.getScheme());
//Log日志如下：
/* 11-14 20:27:13.775 6291-6291/com.example.liang.myapplication I/xinxi: intent.getData().toString()为：content://com.android.providers.media.documents/document/image%3A756326
11-14 20:27:13.775 6291-6291/com.example.liang.myapplication I/xinxi: uri.getAuthority()为：com.android.providers.media.documents
11-14 20:27:13.775 6291-6291/com.example.liang.myapplication I/xinxi: uri.getScheme()为：content
11-14 20:27:13.785 6291-6291/com.example.liang.myapplication I/xinxi: DocumentsContract.getDocumentId(uri)为：image:756326
11-14 20:27:31.925 6291-6291/com.example.liang.myapplication I/xinxi: intent.getData().toString()为：content://com.android.providers.media.documents/document/image%3A730538
11-14 20:27:31.925 6291-6291/com.example.liang.myapplication I/xinxi: uri.getAuthority()为：com.android.providers.media.documents
11-14 20:27:31.925 6291-6291/com.example.liang.myapplication I/xinxi: uri.getScheme()为：content
11-14 20:27:31.925 6291-6291/com.example.liang.myapplication I/xinxi: DocumentsContract.getDocumentId(uri)为：image:730538
11-14 20:28:07.195 6291-6291/com.example.liang.myapplication I/xinxi: intent.getData().toString()为：content://com.android.providers.media.documents/document/image%3A124644
11-14 20:28:07.195 6291-6291/com.example.liang.myapplication I/xinxi: uri.getAuthority()为：com.android.providers.media.documents
11-14 20:28:07.195 6291-6291/com.example.liang.myapplication I/xinxi: uri.getScheme()为：content
11-14 20:28:07.195 6291-6291/com.example.liang.myapplication I/xinxi: DocumentsContract.getDocumentId(uri)为：image:124644*/
if (DocumentsContract.isDocumentUri(this, uri)) {
String docid = DocumentsContract.getDocumentId(uri);
Log.i("xinxi", "DocumentsContract.getDocumentId(uri)为：" + DocumentsContract.getDocumentId(uri));
if ("com.android.providers.media.documents".equals(uri.getAuthority())) {
String id = docid.split(":")[1];
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/public_downloads"), Long.parseLong(docid));
imagepath = getImagePath(contenturi, null);
}
} else if ("content".equalsIgnoreCase(uri.getScheme())) {
imagepath = getImagePath(uri, null);
} else if ("file".equalsIgnoreCase(uri.getScheme())) {
imagepath = uri.getPath();
}
showImage(imagepath);
}
private void another(Intent intent) {
Uri uri = intent.getData();
String imagepath = getImagePath(uri, null);
showImage(imagepath);
}
private void showImage(String imagepath) {
if (imagepath != null) {
Bitmap bitmap = BitmapFactory.decodeFile(imagepath);
imageView.setImageBitmap(bitmap);
} else {
Toast.makeText(this, "没有得到图片", Toast.LENGTH_SHORT).show();
}
}
private String getImagePath(Uri externalContentUri, String selection) {
String path = null;
Cursor cursor = getContentResolver().query(externalContentUri, null, selection, null, null);
if (cursor != null) {
if (cursor.moveToNext()) {
path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
}
cursor.close();
}
return path;
}
记得在androidmanifest中申明
例三：简单的音乐播放器
device-2017-11-14-211121.png
public class MainActivity extends AppCompatActivity {
private Button button;
private Button button1;
private Button button2;
private MediaPlayer mediaplayer = new MediaPlayer();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
quanxian();
setContentView(R.layout.activity_main);
button = (Button) findViewById(R.id.button);
button1 = (Button) findViewById(R.id.button1);
button2 = (Button) findViewById(R.id.button2);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (!mediaplayer.isPlaying()) {
mediaplayer.start();
}
}
});
button1.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v) {
if (mediaplayer.isPlaying()) {
mediaplayer.pause();
}
}
});
button2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mediaplayer.isPlaying()) {
mediaplayer.reset();
chushihua();
}
}
});
}
private void quanxian() {
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 {
chushihua();
}
}
private void chushihua() {
File file = new File(Environment.getExternalStorageDirectory(), "1.mp3");//要想得到手机存储中任意文件的路径就需要用到Environment，如果是app的关联缓存路径的话直接getExternalCacheDir()
Log.i("xinxi", "Environment.getExternalStorageDirectory()为：" + Environment.getExternalStorageDirectory() + "");
Log.i("xinxi", "file.getPath()为" + file.getPath());
/* Log日志输出如下：
11-14 21:14:21.265 22529-22529/com.example.liang.myapplication I/xinxi: Environment.getExternalStorageDirectory()为：/storage/emulated/0
11-14 21:14:21.265 22529-22529/com.example.liang.myapplication I/xinxi: file.getPath()为/storage/emulated/0/1.mp3*/
try {
mediaplayer.setDataSource(file.getPath());
mediaplayer.prepare();
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {//这个方法是当系统提示用户是否开启权限的时，当用户选择开启或者是禁止时触发的
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode) {
case (1):
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED)//grant是同意的意思，grantResults这个参数中放的是0或者是1，0表示同意，1表示禁止
{
Toast.makeText(MainActivity.this, "已经有权限了", Toast.LENGTH_SHORT).show();
chushihua();
} else {
Toast.makeText(MainActivity.this, "请先申请权限", Toast.LENGTH_SHORT).show();
}
break;
default:
}
}
@Override
protected void onDestroy() {
super.onDestroy();
if(mediaplayer!=null){
mediaplayer.stop();
mediaplayer.release();
}
}
}
记得在androidmanifest中申明
例四：简单的视频播放器
device-2017-11-14-212720.png
public class MainActivity extends AppCompatActivity {
private Button button;
private Button button1;
private Button button2;
private VideoView videoview;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button) findViewById(R.id.button);
button1 = (Button) findViewById(R.id.button1);
button2 = (Button) findViewById(R.id.button2);
videoview= (VideoView) findViewById(R.id.videoView);
quanxian();
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (!videoview.isPlaying()) {
videoview.start();//开始播放
}
}
});
button1.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v) {
if (videoview.isPlaying()) {
videoview.pause();//暂停播放
}
}
});
button2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (videoview.isPlaying()) {
videoview.resume();//重新播放
}
}
});
}
private void quanxian() {
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 {
chushihua();
}
}
private void chushihua() {
File file = new File(Environment.getExternalStorageDirectory(), "mo.mp4");//要想得到手机存储中任意文件的路径就需要用到Environment，如果是app的关联缓存路径的话直接getExternalCacheDir()
Log.i("xinxi", "Environment.getExternalStorageDirectory()为：" + Environment.getExternalStorageDirectory() + "");
Log.i("xinxi", "file.getPath()为" + file.getPath());
/* Log日志输出如下：
11-14 21:14:21.265 22529-22529/com.example.liang.myapplication I/xinxi: Environment.getExternalStorageDirectory()为：/storage/emulated/0
11-14 21:14:21.265 22529-22529/com.example.liang.myapplication I/xinxi: file.getPath()为/storage/emulated/0/mo.mp4*/
videoview.setVideoPath(file.getPath());
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {//这个方法是当系统提示用户是否开启权限的时，当用户选择开启或者是禁止时触发的
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode) {
case (1):
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED)//grant是同意的意思，grantResults这个参数中放的是0或者是1，0表示同意，1表示禁止
{
Toast.makeText(MainActivity.this, "已经有权限了", Toast.LENGTH_SHORT).show();
chushihua();
} else {
Toast.makeText(MainActivity.this, "请先申请权限", Toast.LENGTH_SHORT).show();
}
break;
default:
}
}
@Override
protected void onDestroy() {
super.onDestroy();
if(videoview!=null){
videoview.suspend();
}
}
}
记得在androidmanifest中申明