PS1: Dynamically obtain permissions:
| English | Features |
|---|---|
| android.permission.ACCESS_FINE_LOCATION | Allow a program to access sophisticated locations (such as GPS) |
| android.permission.ACCESS_NETWORK_STATE | GSM location information |
| android.permission.ACCESS_WIFI_STATE | Get Wifi situation |
| android.permission.BLUETOOTH | Allow discovery of Bluetooth |
| android.permission.BLUETOOTH_ADMIN | Allow Bluetooth pairing |
| android.permission.CAMERA | Allow access to camera |
| android.permission.CHANGE_WIFI_STATE | Allow to change the network WIFI status |
| android.permission.FLASHLIGHT | Allow access to flash |
| android.permission.INTERNET | Allow network requests |
| android.permission.READ_CONTACTS | Allow access to contacts |
| android.permission.READ_SMS | Allow SMS |
| android.permission.RECEIVE_SMS | Allow monitoring of SMS |
| WRITE_EXTERNAL_STORAGE | Allow writing |
| android.permission.VIBRATE | Allow vibration |
Steps: first determine whether you have permission
if(ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED)//判断是否获得权限
{
ActivityCompat.requestPermissions(this, new String[]{
Manifest.permission.WRITE_EXTERNAL_STORAGE}, 100);}//获取权限
Multiple permissions request at the same time
private void CheckAndroidPermission() {
List<String> permissionLists = new ArrayList<>();
if(ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED){
permissionLists.add(Manifest.permission.CAMERA);
}
if(ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED){
permissionLists.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);
}
if(ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED){
permissionLists.add(Manifest.permission.READ_EXTERNAL_STORAGE);
}
if(!permissionLists.isEmpty()){
//说明肯定有拒绝的权限
ActivityCompat.requestPermissions(this, permissionLists.toArray(new String[permissionLists.size()]), REQUEST_IMAGE_CAPTURE);
}else{
//获得了权限 就做你要做的事了
}
}
For user experience, rewrite the callback function to obtain permission settings
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);//grantResults用来存放被拒绝的权限
switch (requestCode){
case REQUEST_IMAGE_CAPTURE:
if(grantResults.length > 0){
for(int grantResult : grantResults){
if(grantResult != PackageManager.PERMISSION_GRANTED){
Toast.makeText(this, "某一个权限被拒绝了", Toast.LENGTH_SHORT).show();
return;
}
}
//执行后面的代码
}
break;
default:
break;
}
}
Call camera
After the permission is obtained, the camera can be called
private void findCarmer() {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);//跳转调用相机
Uri uri = Uri.fromFile(new File(picPath));//设置路径，这里picpath是我放在外面设置的全局参数
if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, uri);//携带参数跳转，告诉相机你存储位置
startActivityForResult(takePictureIntent, 2);//表示需要返回原图，如果返回缩略图这里的2改成1
}
}
Then rewrite the response function to convert the returned data into bitmap format to imageview
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
FileInputStream fis=null;
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 2 ) {
try {
Log.e("sdPath2",picPath);
//把图片转化为字节流
fis = new FileInputStream(picPath);
//把流转化图片
Bitmap bitmap = BitmapFactory.decodeStream(fis);
imageView.setImageBitmap(bitmap);
fis.close();
} catch (IOException e) {
Log.i("mm", e.toString());
}
}
}
There are two pits here. After the high version of Android is updated, it needs to be added in the OnCreat method
StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
StrictMode.setVmPolicy(builder.build());
builder.detectFileUriExposure();
Then when reading from external storage, you need to add a sentence in AndRoidMainfest.xml
android:requestLegacyExternalStorage="true">//新版本需要添加这个语句才能允许读取相片 Android Q分区存储权限变更及适配问题：
Complete code:
package com.example.viewpager;
import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import androidx.core.content.FileProvider;
import android.Manifest;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Camera;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.os.StrictMode;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class Carmer extends AppCompatActivity {
static final int REQUEST_IMAGE_CAPTURE = 100;
private Button button;
ImageView imageView;
String sdPath = Environment.getExternalStorageDirectory().getAbsolutePath()+"/dangjian";
String picPath = sdPath + "/" + "temp.png";
@RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_carmer);
StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
StrictMode.setVmPolicy(builder.build());
builder.detectFileUriExposure();
button=findViewById(R.id.carmer);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
CheckAndroidPermission();
findCarmer();
}
});
imageView=findViewById(R.id.mte);
}
private void CheckAndroidPermission() {
List<String> permissionLists = new ArrayList<>();
if(ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED){
permissionLists.add(Manifest.permission.CAMERA);
}
if(ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED){
permissionLists.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);
}
if(ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED){
permissionLists.add(Manifest.permission.READ_EXTERNAL_STORAGE);
}
if(!permissionLists.isEmpty()){
//说明肯定有拒绝的权限
ActivityCompat.requestPermissions(this, permissionLists.toArray(new String[permissionLists.size()]), REQUEST_IMAGE_CAPTURE);
}else{
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode){
case REQUEST_IMAGE_CAPTURE:
if(grantResults.length > 0){
for(int grantResult : grantResults){
if(grantResult != PackageManager.PERMISSION_GRANTED){
Toast.makeText(this, "某一个权限被拒绝了", Toast.LENGTH_SHORT).show();
return;
}
}
//其他逻辑(这里当权限都同意的话就执行打电话逻辑)
findCarmer();
}
break;
default:
break;
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
FileInputStream fis=null;
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 2 ) {
try {
Log.e("sdPath2",picPath);
//把图片转化为字节流
fis = new FileInputStream(picPath);
//把流转化图片
Bitmap bitmap = BitmapFactory.decodeStream(fis);
imageView.setImageBitmap(bitmap);
fis.close();
} catch (IOException e) {
Log.i("mm", e.toString());
}
}
}
private void findCarmer() {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
Uri uri = Uri.fromFile(new File(picPath));
if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, uri);
startActivityForResult(takePictureIntent, 2);
}
}
}