本文主要介紹的是從手機中獲取照片並且壓縮後顯示在imageview或者呼叫手機相機拍照之後壓縮顯示在imageView中，具有很好的參考意義，同時兼顧了Android7.0對於呼叫手機相機的設定問題。有需要的可以借鑑一下：

1.XML佈局檔案程式碼

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <ImageView android:id="@+id/imageView"
        android:adjustViewBounds="true"
        android:layout_gravity="center"
        android:minWidth="150dip"
        android:minHeight="150dip"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
    <Button android:id="@+id/btnPhone"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="相簿" />
    <Button android:id="@+id/btnTakePicture"
        android:layout_height="wrap_content"
        android:layout_width="fill_parent"
        android:text="拍照" />
</LinearLayout>
 

2.Activity程式碼

package com.apress.gerber.camera;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.os.StrictMode;
import android.provider.MediaStore;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

import java.io.ByteArrayOutputStream;
import java.io.File;

public class MainActivity extends Activity {
    private static final int NONE = 0;
    private static final int PHOTO_GRAPH = 1;// 拍照
    private static final int PHOTO_ZOOM = 2; // 縮放
    private static final int PHOTO_RESOULT = 3;// 結果
    private static final String IMAGE_UNSPECIFIED = "image/*";
    private ImageView imageView = null;
    private Button btnPhone = null;
    private Button btnTakePicture = null;
    private String change_path = "/peoplechanged";
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        imageView = (ImageView) findViewById(R.id.imageView);
        btnPhone = (Button) findViewById(R.id.btnPhone);
        btnPhone.setOnClickListener(onClickListener);
        btnTakePicture = (Button) findViewById(R.id.btnTakePicture);
        btnTakePicture.setOnClickListener(onClickListener);
        StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
        StrictMode.setVmPolicy(builder.build());
        builder.detectFileUriExposure();
    }
    private final View.OnClickListener onClickListener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if(v==btnPhone){ //從相簿獲取圖片
                Intent intent = new Intent(Intent.ACTION_PICK, null);
                intent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, IMAGE_UNSPECIFIED);
                startActivityForResult(intent, PHOTO_ZOOM);
            }else if(v==btnTakePicture){ //從拍照獲取圖片
                String filePath = Environment.getExternalStorageDirectory()+change_path;
                File localFile = new File(filePath);
                if (!localFile.exists()) {
                    localFile.mkdir();
                }
                Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(new File(Environment.getExternalStorageDirectory()+change_path
                        ,"temp.jpg")));
                startActivityForResult(intent, PHOTO_GRAPH);
            }
        }
    };
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (resultCode == NONE)
            return;
        // 拍照
        if (requestCode == PHOTO_GRAPH) {
            // 設定檔案儲存路徑
            String filePath = Environment.getExternalStorageDirectory()+change_path;
            File localFile = new File(filePath);
            if (!localFile.exists()) {
                localFile.mkdir();
            }
            File picture = new File(Environment.getExternalStorageDirectory()+change_path
                    + "/temp.jpg");
            startPhotoZoom(Uri.fromFile(picture));
        }
        if (data == null)
            return;
        // 讀取相簿縮放圖片
        if (requestCode == PHOTO_ZOOM) {
            startPhotoZoom(data.getData());
        }
        // 處理結果
        if (requestCode == PHOTO_RESOULT) {
            Bundle extras = data.getExtras();
            if (extras != null) {
                Bitmap photo = extras.getParcelable("data");
                ByteArrayOutputStream stream = new ByteArrayOutputStream();
                photo.compress(Bitmap.CompressFormat.JPEG, 75, stream);// (0-100)壓縮檔案
                //此處可以把Bitmap儲存到sd卡中
                imageView.setImageBitmap(photo); //把圖片顯示在ImageView控制元件上
            }
        }
        super.onActivityResult(requestCode, resultCode, data);
    }
    /**
     * 收縮圖片
     *
     * @param uri
     */
    public void startPhotoZoom(Uri uri) {
        Intent intent = new Intent("com.android.camera.action.CROP");
        intent.setDataAndType(uri, IMAGE_UNSPECIFIED);
        intent.putExtra("crop", "true");
        // aspectX aspectY 是寬高的比例
        intent.putExtra("aspectX", 1);
        intent.putExtra("aspectY", 1);
        // outputX outputY 是裁剪圖片寬高
        intent.putExtra("outputX", 300);
        intent.putExtra("outputY", 500);
        intent.putExtra("return-data", true);
        startActivityForResult(intent, PHOTO_RESOULT);
    }
}
 

        // android 7.0系統解決拍照的問題
        StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
        StrictMode.setVmPolicy(builder.build());
        builder.detectFileUriExposure(); 

android.os.FileUriExposedException: file:///storage/emulated/0/photo.jpeg exposed beyond app through ClipData.Item.getUri()

這樣，複製XML和Activity檔案即可執行，實現對手機圖片的獲取和相機的呼叫