Question

我正在尝试创建一个应用程序，我想在其中使用媒体API，然后打开相机并使用拍照并在

中显示照片

MainActivity.java

package com.example.hsports.cameraapiuse;

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.os.Build;
import android.provider.MediaStore;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import org.w3c.dom.Text;

import java.util.jar.Manifest;

public class MainActivity extends AppCompatActivity {

    static final int REQUEST_IMAGE_CAPTURE = 1;
    static final int MY_PERMISSIONS_REQUEST_CAMERA=2;

    ImageView mImageView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mImageView=(ImageView)findViewById(R.id.mImageView);
    }


    public void dispatchTakePictureIntent() {

        Intent takepicture=new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        if(takepicture.resolveActivity(getPackageManager())!=null) {
            startActivityForResult(takepicture, REQUEST_IMAGE_CAPTURE);
        }
    }


    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {
            Bundle extras = data.getExtras();
            Bitmap imageBitmap = (Bitmap) extras.get("data");
            mImageView.setImageBitmap(imageBitmap);
        }
    }


    public void checkPermission(View view)
    {
        int permissionCheck=ContextCompat.checkSelfPermission(this, android.Manifest.permission.CAMERA);

    }

    public void grantPermission(View view)
    {
        if(ContextCompat.checkSelfPermission(this, android.Manifest.permission.CAMERA)!=PackageManager.PERMISSION_GRANTED)
        {

        }
        else
        {
            ActivityCompat.requestPermissions(this, new String[] {android.Manifest.permission.CAMERA},MY_PERMISSIONS_REQUEST_CAMERA);

        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {

        switch(requestCode)
        {
            case MY_PERMISSIONS_REQUEST_CAMERA:
                if (grantResults.length > 0
                        && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                    dispatchTakePictureIntent();
                } else {


                }
                return;
        }
    }
}

activity_main.xml（在这里我添加了一个textview和一个用于查看相机将拍摄的图像的imageView）

<?xml version="1.0" encoding="utf-8"?>
<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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context="com.example.hsports.cameraapiuse.MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        android:id="@+id/permission"
        />

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/mImageView"
        />


    <Button
        android:id="@+id/check_permission"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Check Permission"
        android:onClick="checkPermission"
      />

    <Button
        android:id="@+id/request_permission"    
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Request Permission"
        android:onClick="grantPermission"    
        />            

</LinearLayout>

Android_manifest.xml（在这里我已经指定了一些使用相机作为硬件的使用权限。）

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.hsports.cameraapiuse">

    <uses-permission
        android:name="android.permission.CAMERA"
        android:required="true"
        />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        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>
    </application>                          
</manifest>

执行此代码后，单击“请求权限”按钮后，我没有打开任何相机。我希望相机打开并单击照片并显示在imageView中。

Answer 1

根据您运行的Android版本（例如Marshmallow），您可能需要检查运行时持久性。

请查看以下链接，其中显示了相机的示例。

https://developer.android.com/training/permissions/requesting.html

引起：java.lang.SecurityException：Permission Denial：} with revoked permission android.permission.CAMERA

1 个答案: