MainActivity.kt
package com.example.fredric.takephoto
import android.Manifest
import android.app.Activity
import android.content.Intent
import android.content.pm.PackageManager
import android.graphics.BitmapFactory
import android.net.Uri
import android.os.Build
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.provider.DocumentsContract
import android.provider.MediaStore
import android.support.annotation.RequiresApi
import android.support.v4.app.ActivityCompat
import android.support.v4.content.ContextCompat
import android.support.v4.content.FileProvider
import android.util.Log
import android.widget.Button
import android.widget.ImageView
import android.widget.Toast
import java.io.File
import java.io.IOException
import android.content.ContentUris
class MainActivity : AppCompatActivity() {
val TAKE_PHOTO: Int = 1
val CHOOSE_PHOTO: Int = 2
var picture: ImageView? = null
var imageUri: Uri? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
var takePhoto = findViewById<Button>(R.id.take_photo)
var chooseFromAlbum = findViewById<Button>(R.id.choose_from_album)
picture = findViewById<ImageView>(R.id.picture)
takePhoto.setOnClickListener{
var outputImage = File(externalCacheDir,"output_image.jpg")
try{
if(outputImage.exists()) {
outputImage.delete()
}
}catch (ex: IOException) {
ex.printStackTrace()
}
if(Build.VERSION.SDK_INT < Build.VERSION_CODES.N) {
imageUri = Uri.fromFile(outputImage)
}else {
imageUri = FileProvider.getUriForFile(MainActivity@this,"com.example.fredric.takephoto.fileprovider",outputImage)
}
val intent = Intent("android.media.action.IMAGE_CAPTURE")
intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri)
startActivityForResult(intent, TAKE_PHOTO)
}
chooseFromAlbum.setOnClickListener{
if(ContextCompat.checkSelfPermission(MainActivity@this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(MainActivity@this, arrayOf(Manifest.permission.WRITE_EXTERNAL_STORAGE),1)
}else {
openAlbum()
}
}
}
fun openAlbum() {
val intent = Intent("android.intent.action.GET_CONTENT")
intent.setType("image/*")
startActivityForResult(intent, CHOOSE_PHOTO)
}
override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {
when(requestCode) {
1 -> {
if(grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
openAlbum()
}else {
Toast.makeText(MainActivity@this,"You denied this permission!!",Toast.LENGTH_SHORT).show()
}
}
else -> {
}
}
}
@RequiresApi(Build.VERSION_CODES.KITKAT)
fun handleImageOnKitkat(data:Intent?) {
var imagePath:String? = null
var uri = data?.data
Log.d("TAG","handleImageOnKitkat: Uri is: "+uri)
if(DocumentsContract.isDocumentUri(this,uri)) {
var docId = DocumentsContract.getDocumentId(uri)
if("com.android.providers.media.documents".equals(uri?.authority)) {
val id = docId.split(":")[1]
var selection = MediaStore.Images.Media._ID + "=" + id
imagePath = getImagePath(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, selection)
}else if ("com.android.providers.downloads.documents".equals(uri?.authority)) {
val contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), docId.toLong())
imagePath = getImagePath(contentUri,null)
}
}else if("content".equals(uri?.scheme,true)){
imagePath = getImagePath(uri, null)
}else if("file".equals(uri?.scheme,true)) {
imagePath = uri?.getPath()
}
displayImage(imagePath)
}
fun handleImageBeforeKitkat(data:Intent?) {
val uri = data?.data
var imagePath:String? = getImagePath(uri,null)
displayImage(imagePath)
}
fun getImagePath(uri: Uri?, selection: String?): String? {
var path: String? = null
var cursor = contentResolver.query(uri,null,selection,null,null)
if(cursor!=null) {
if(cursor.moveToFirst()) {
path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA))
}
cursor.close()
}
return path
}
fun displayImage(imagePath:String?) {
if(imagePath!=null) {
val bitmap = BitmapFactory.decodeFile(imagePath)
picture?.setImageBitmap(bitmap)
}else {
Toast.makeText(this,"Failed to get image!!",Toast.LENGTH_SHORT).show()
}
}
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
when(requestCode) {
TAKE_PHOTO -> {
if(resultCode == Activity.RESULT_OK) {
try{
val bitmap = BitmapFactory.decodeStream(contentResolver.openInputStream(imageUri))
picture?.setImageBitmap(bitmap)
}catch (ex: Exception) {
ex.printStackTrace()
}
}
}
CHOOSE_PHOTO -> {
if(resultCode == Activity.RESULT_OK) {
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
handleImageOnKitkat(data)
}else {
handleImageBeforeKitkat(data)
}
}
}
else -> {
}
}
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:id="@+id/take_photo"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Take Photo" />
<Button
android:id="@+id/choose_from_album"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Choose From Album" />
<ImageView
android:id="@+id/picture"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
/>
</LinearLayout>
res/xml/file_paths.xml
<?xml version="1.0" encoding="utf-8" ?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-path name="my_images" path="" />
</paths>
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.fredric.takephoto">
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:testOnly="false"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<provider
android:name="android.support.v4.content.FileProvider"
android:authorities="com.example.fredric.takephoto.fileprovider"
android:exported="false"
android:grantUriPermissions="true"
>
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/file_paths"/>
</provider>
</application>
</manifest>
运行效果如图，
Screenshot_20180722-081309-093.jpg
