AndroidStudio调用摄像头

逻辑部分：

package com.example.qing.third;

import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Build;
import android.provider.MediaStore;
import android.support.annotation.Nullable;
import android.support.v4.content.FileProvider;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;

public class MainActivity extends AppCompatActivity {
    public static final int TAKE_PHOTO=1;
    private ImageView picture;
    private Uri imageUri;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button takePhoto=(Button)findViewById(R.id.take_photo);
        picture=(ImageView)findViewById(R.id.picture);
        takePhoto.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                File outputImage=new File(getExternalCacheDir(),"output_image.jpg");
                try{
                    if(outputImage.exists()){
                        outputImage.delete();
                    }
                    outputImage.createNewFile();
                }catch (IOException e){
                    e.printStackTrace();
                }
                if(Build.VERSION.SDK_INT>=24){
                    imageUri=FileProvider.getUriForFile(MainActivity.this,"com.example.cameraalbumtest.fileprovider",outputImage);
                }
                else{
                    imageUri=Uri.fromFile(outputImage);
                }

                Intent intent=new Intent("android.media.action.IMAGE_CAPTURE");
                intent.putExtra(MediaStore.EXTRA_OUTPUT,imageUri);
                startActivityForResult(intent,TAKE_PHOTO);
            }
        });

    }

    @Override  //使用的是startActivityForResult会有结果返回到onActivityResult方法中去
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        switch (requestCode){
            case TAKE_PHOTO:
                if(resultCode==RESULT_OK){
                    try{
                        Bitmap bitmap=BitmapFactory.decodeStream(getContentResolver().openInputStream(imageUri));
                        picture.setImageBitmap(bitmap);
                    }catch (FileNotFoundException e){
                        e.printStackTrace();
                    }

                }
                break;
            default:
                break;
        }
    }
}

布局部分：

xml：