相册系列：简单实现打开相册选图片功能

Posted 2021-06-26 zhangjin1120

先上效果图：

点击	可以拍照

打钩选择	完成

• 使用的github库：Lichenwei-Dev/ImagePicker
• 添加依赖:

    implementation 'com.github.bumptech.glide:glide:4.9.0'
    implementation 'com.lcw.library:imagepicker:2.2.7'

• 准备GlideLoader.java，需要一张图片icon_image_error.png。
  
  需要个MApplication.java传递Context

public class MApplication extends Application {

    private static MApplication mApplication;

    @Override
    public void onCreate() {
        super.onCreate();
        mApplication = this;
    }

    public static MApplication getContext() {
        return mApplication;
    }
}

glide 4.9.0对应的GlideLoader.java源码：

public class GlideLoader implements ImageLoader {

    private RequestOptions mOptions = new RequestOptions()
            .centerCrop()
            .format(DecodeFormat.PREFER_RGB_565)
            .placeholder(R.mipmap.icon_image_default)
            .error(R.drawable.icon_image_error);

    private RequestOptions mPreOptions = new RequestOptions()
            .skipMemoryCache(true)
            .error(R.drawable.icon_image_error);

    @Override
    public void loadImage(ImageView imageView, String imagePath) {
        //小图加载
        Glide.with(imageView.getContext()).load(imagePath).apply(mOptions).into(imageView);
    }

    @Override
    public void loadPreImage(ImageView imageView, String imagePath) {
        //大图加载
        Glide.with(imageView.getContext()).load(imagePath).apply(mPreOptions).into(imageView);

    }

    @Override
    public void clearMemoryCache() {
        //清理缓存
        Glide.get(MApplication.getContext()).clearMemory();
    }
}

如果是gilde 3.7 ，则对应的GlideLoader.java简写如下，问题也不大：

public class GlideLoader implements ImageLoader {

    @Override
    public void loadImage(ImageView imageView, String imagePath) {
        //小图加载
        Glide.with(imageView.getContext()).load(imagePath).into(imageView);
    }

    @Override
    public void loadPreImage(ImageView imageView, String imagePath) {
        //大图加载
        Glide.with(imageView.getContext()).load(imagePath).into(imageView);

    }

    @Override
    public void clearMemoryCache() {
        //清理缓存
        Glide.get(MApplication.getContext()).clearMemory();
    }
}

• 弄个MainActivity.java测试一下：

public class MainActivity extends AppCompatActivity {
    private static final int REQUEST_SELECT_IMAGES_CODE = 0x01;
    private ArrayList<String> mImagePaths;
    private TextView tvPath;
    private ImageView iv;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tvPath = findViewById(R.id.tv_path);
        iv = findViewById(R.id.iv);
    }

    public void openAlbum(View view) {
        ImagePicker.getInstance()
                .setTitle("图片")//设置标题
                .showCamera(true)//设置是否显示拍照按钮
                .showImage(true)//设置是否展示图片
                .showVideo(true)//设置是否展示视频
                .setSingleType(true)//设置图片视频不能同时选择
                .setMaxCount(4)//设置最大选择图片数目(默认为1，单选)
                .setImageLoader(new GlideLoader())//设置自定义图片加载器
                .start(MainActivity.this, REQUEST_SELECT_IMAGES_CODE);//REQEST_SELECT_IMAGES_CODE为Intent调用的requestCode
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == REQUEST_SELECT_IMAGES_CODE && resultCode == RESULT_OK) {
            mImagePaths = data.getStringArrayListExtra(ImagePicker.EXTRA_SELECT_IMAGES);
            StringBuffer stringBuffer = new StringBuffer();
            stringBuffer.append("当前选中图片路径：\\n\\n");
            for (int i = 0; i < mImagePaths.size(); i++) {
                stringBuffer.append(mImagePaths.get(i) + "\\n\\n");
            }

            tvPath.setText(stringBuffer.toString());

            Glide.with(MainActivity.this).load(mImagePaths.get(0)).into(iv);
        }
    }
}

完工！