三种方式绘制图片

1. ImageView 绘制图片

package com.ddx.testimageview;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.ImageView;

import java.io.File;

public class ShowImageView extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_show_image_view);
        //Bitmap bitmap = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory().getPath() + File.separator + "11.jpg");
        Bitmap bitmap = BitmapFactory.decodeFile(Environment.getDataDirectory().getPath() + File.separator + "11.jpg");
        Log.d("DDX", "externalStorageDirectory = " + Environment.getExternalStorageDirectory().getPath() + File.separator + "11.jpg");
        ImageView imageView = (ImageView) findViewById(R.id.imageView);
        imageView.setImageBitmap(bitmap);
    }
}