调用摄像头拍照 camera

package com.gao.choosepictest;

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

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

/**
 * 调用摄像头 拍照
 * 点击完成，就会回到我们程序的界面。同时，裁剪后的照片当然也会显示出来了
 */
public class MainActivity extends AppCompatActivity {
    public static final int TAKE_PHOTO = 1;
    public static final int CROP_PHOTO = 2;

    private Button takePhoto; //拍照
    private ImageView picture; //显示拍摄图片
    private Button chooseFromAlbum;// 从相机中选取
    private Uri imageUri;

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

        takePhoto = (Button) findViewById(R.id.take_photo);
        chooseFromAlbum = (Button) findViewById(R.id.choose_from_album);
        picture = (ImageView) findViewById(R.id.picture);

        //从相册选取
        chooseFromAlbum.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //  创建File 用于存储选择的照片
                File file = new File(Environment.getExternalStorageDirectory(), "img.png");
                if (file.exists()) {
                    file.delete();
                }
                try {
                    file.createNewFile();
                } catch (IOException e) {
                    e.printStackTrace();
                }

                imageUri = Uri.fromFile(file);
                Intent intent = new Intent("android.intent.action.GET_CONTENT");
                intent.setType("image/*");
                intent.putExtra("crop", true); //裁减
                intent.putExtra("scale", true); //缩放
                intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
                startActivityForResult(intent, CROP_PHOTO);

            }
        });

        //相机拍照
        takePhoto.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // 创建File对象，用于存储拍照后的图片
                File file = new File(Environment.getExternalStorageDirectory(), "tempImg.jpg");
                if (file.exists()) {
                    file.delete();
                }
                try {
                    file.createNewFile();
                } catch (IOException e) {
                    e.printStackTrace();
                }

                //将 File 对象转换成 Uri 对象
                imageUri = Uri.fromFile(file);
                Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
                intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
                startActivityForResult(intent, TAKE_PHOTO); // 启动相机程序
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {

        switch (requestCode) {
            case TAKE_PHOTO:
                if (resultCode == RESULT_OK) {
                    Intent intent = new Intent("com.android.camera.action.CROP");
                    intent.setDataAndType(imageUri, "image/*");
                    intent.putExtra("scale", true);
                    intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
                    startActivityForResult(intent, CROP_PHOTO); // 启动裁剪程序
                }
                break;
            case CROP_PHOTO:
                if (resultCode == RESULT_OK) {
                    try {
                        //将 output_image.jpg 这张照片解析成 Bitmap 对象
                        Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageUri));

                        picture.setImageBitmap(bitmap); // 将裁剪后的照片显示出来

                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    }
                }

            default:
                break;
        }

        super.onActivityResult(requestCode, resultCode, data);
    }
}

布局文件

<?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:orientation="vertical"
    tools:context="com.gao.choosepictest.MainActivity">
    <Button
        android:id="@+id/choose_from_album"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="从相册中选取" />
    <Button
        android:text="打开摄像头拍照"
        android:id="@+id/take_photo"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

    <ImageView
        android:id="@+id/picture"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal" />
</LinearLayout>

需要加入的权限

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>