android 加载系统相册图片并显示

╰+攻爆jí腚メ 2022-06-08 06:11 299阅读 0赞

1，下载[ImageLoad.jar][]包放入项目libs文件夹中，并点击右键—>add as Library

2，首先记得在Manifest.xml注册权限(**注：6.0以后的版本要在代码中动态注册权限**)

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

3，布局文件，一个ImageView用来显示加载的图片，Button点击后进入系统相册选取图片

<?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.zcn.demo.loadgallerypicture.MainActivity">
    
        <ImageView android:id="@+id/pic" android:src="@mipmap/ic_launcher" android:layout_width="120dp" android:layout_height="120dp" />
        <Button android:id="@+id/btn" android:layout_width="match_parent" android:layout_height="48dp" android:layout_gravity="bottom" android:text="button"/>
    </LinearLayout>

4，.java文件

package com.zcn.demo.loadgallerypicture;
    
    import android.Manifest;
    import android.annotation.TargetApi;
    import android.app.Activity;
    import android.content.Intent;
    import android.content.pm.PackageManager;
    import android.database.Cursor;
    import android.graphics.Bitmap;
    import android.graphics.BitmapFactory;
    import android.net.Uri;
    import android.os.Build;
    import android.support.v4.content.ContextCompat;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.util.Log;
    import android.view.View;
    import android.widget.Button;
    import android.widget.ImageView;
    
    import com.nostra13.universalimageloader.cache.disc.naming.Md5FileNameGenerator;
    import com.nostra13.universalimageloader.core.DisplayImageOptions;
    import com.nostra13.universalimageloader.core.ImageLoader;
    import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
    import com.nostra13.universalimageloader.core.assist.QueueProcessingType;
    
    import java.io.File;
    import java.io.FileOutputStream;
    import java.io.IOException;
    
    public class MainActivity extends AppCompatActivity {
        private static int WRITE_SD_CODE = 1;
        private static int READ_SD_CODE = 2;
        private static String TAG = "ZCN_MainActivity";
        private ImageView image;
        private Button btn;
    
        private String pic_path;
        private DisplayImageOptions options;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            image = (ImageView)findViewById(R.id.pic);
            btn = (Button)findViewById(R.id.btn);
            btn.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    requestPermission();
                }
            });
        }
    
        //android 6.0 以上版本要手动要求权限
        @TargetApi(Build.VERSION_CODES.M)
        private void requestPermission() {
            if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
                this.requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},READ_SD_CODE);
            }else {
                Log.v(TAG, "6.0一下版本直接打开相册....");
                Intent intent = new Intent(Intent.ACTION_PICK,
                        android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                startActivityForResult(intent, ActivityRequestCode.SHOW_MAP_DEPOT);
            }
        }
    
        //权限选择结果接收
        @Override
        public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
            super.onRequestPermissionsResult(requestCode, permissions, grantResults);
            if (requestCode == READ_SD_CODE) {
                if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    // 用户授予了此权限
                    // 调用android自带的图库
                    Intent intent = new Intent(Intent.ACTION_PICK,
                            android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                    startActivityForResult(intent, ActivityRequestCode.SHOW_MAP_DEPOT);
                } else {
                    // 用户拒绝了此权限
                }
            }
        }
    
        public interface ActivityRequestCode {
            public static final int SHOW_MAP_DEPOT = 1; //显示Android自带图库，用于选择用户自己的图片
        }
    
        public void onActivityResult(int requestCode, int resultCode, Intent data) {
            super.onActivityResult(requestCode, resultCode, data);
            if (data != null) {
                if (requestCode == ActivityRequestCode.SHOW_MAP_DEPOT
                        && resultCode == Activity.RESULT_OK)
                    showPic(resultCode,data);
            }
        }
    
        // 调用android自带图库，显示选中的图片
        private void showPic(int resultCode,Intent data) {
            if(resultCode== Activity.RESULT_OK) {
                if (data!=null) {
                    Uri uri = data.getData();
                    Log.v(TAG, "uri = "+uri);
                    if (uri!=null) {
                        Cursor cursor = getContentResolver().query(uri, null, null, null, null);
                        //选择的就只是一张图片，所以cursor只有一条记录
                        if (cursor != null) {
                            if (cursor.moveToFirst()) {
                                String path = cursor.getString(cursor.getColumnIndex("_data"));//获取相册路径字段
                                Log.v(TAG, "打开相册获取的图片sd卡路径:" + path);
                                File file = new File(path);
                                initOptions();
                                ImageLoader.getInstance().displayImage(uri.toString(), image,options);
                                //保存图片到data/data/files文件夹下
                                BitmapFactory.Options options = new BitmapFactory.Options();
                                options.inJustDecodeBounds = true;
                                Bitmap bitmap = BitmapFactory.decodeFile(path, options);
                                File f = getFileStreamPath("ic_mine_head_portrait.jpg");
                                Log.d(TAG, "File path :" + file.getParentFile());
                                if (!f.exists()) {
                                    Log.d(TAG, "文件不存在");
                                    FileOutputStream out = null;
                                    try{
                                        f.createNewFile();
                                        out = new FileOutputStream(f);
                                        if(bitmap.compress(Bitmap.CompressFormat.PNG, 90, out))
                                        {
                                            out.flush();
                                            out.close();
                                        }
                                    } catch (IOException e) {
                                        e.printStackTrace();
                                    }finally {
                                        try {
                                            out.close();
                                        } catch (IOException e) {
                                            e.printStackTrace();
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            }else{
                Log.d(TAG,"放弃从相册选择");
            }
        }
    
        private void initOptions(){
            options = new DisplayImageOptions.Builder().showStubImage(R.mipmap.ic_main_ad_stub) // 设置图片下载期间显示的图片
                    .showImageForEmptyUri(R.mipmap.ic_main_ad_empty) // 设置图片Uri为空或是错误的时候显示的图片
                    .showImageOnFail(R.mipmap.ic_main_ad_error) // 设置图片加载或解码过程中发生错误显示的图片
                    .cacheInMemory(true) // 设置下载的图片是否缓存在内存中
                    .cacheOnDisc(true) // 设置下载的图片是否缓存在SD卡中
                    // .displayer(new RoundedBitmapDisplayer(20)) // 设置成圆角图片
                    .build(); // 创建配置过得DisplayImageOption对象
    
            ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(this.getApplicationContext()).defaultDisplayImageOptions(options)
                    .threadPriority(Thread.NORM_PRIORITY - 2).denyCacheImageMultipleSizesInMemory()
                    .discCacheFileNameGenerator(new Md5FileNameGenerator()).tasksProcessingOrder(QueueProcessingType.LIFO).build();
            ImageLoader.getInstance().init(config);
        }
    }

后续：显示图片所使用的uri：

String imageUri = "http://site.com/image.png"; // from Web
    String imageUri = "file:///mnt/sdcard/image.png"; // from SD card
    String imageUri = "content://media/external/audio/albumart/13"; // from content provider
    String imageUri = "assets://image.png"; // from assets
    String imageUri = "drawable://" + R.drawable.image; // from drawables (only images, non-9patch)

**注意：使用drawable://除非你真的需要他。时刻要注意使用本地图片加载方法：setImageResource带代替ImageLoader。**

[ImageLoad.jar]: https://github.com/596785154/ImageLLoaderJar/blob/master/universal-image-loader-1.9.5.jar