一、获取图片大小有两张情况代码如下：
package com.jhq.picdemo;import android.Manifest;import android.content.pm.PackageManager;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.support.v4.app.ActivityCompat;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.util.Log;public class MainActivity extends AppCompatActivity {private String TAG = "MainActivity";private String path = "/storage/emulated/0/data/mytest/mytest.png"; //图片路径@Override protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);checkPermission(); //权限检查}protected void onResume () {super.onResume();getImageSize(); //获取尺寸大小}private void getImageSize() {/*第一种直接把bitmap加载到内存中，通过对bitmap的测量，得出宽高，由于这个方法直接把图片引入内存，如果图片过大，将会引发OOM；*///方法一：通过uri把图片转化为bitmap的方法Bitmap bitmap= BitmapFactory.decodeFile(path);//从本地sdcard获取图片，如从其他文件中获取图片，可参考文末的链接。int height= bitmap.getHeight();int width= bitmap.getWidth();Log.i(TAG,"通过bitmap获取到的图片大小" + "width: "+ width+" height: "+ height);/*bitmap.options类为bitmap的裁剪类，通过他可以实现bitmap的裁剪；如果不设置裁剪后的宽高和裁剪比例，返回的bitmap对象将为空，但是这个对象存储了原bitmap的宽高信息。*///方法二：使用Options类来获取BitmapFactory.Options options = new BitmapFactory.Options();options.inJustDecodeBounds = true;//这个参数设置为true才有效，Bitmap bmp = BitmapFactory.decodeFile(path, options);//这里的bitmap是个空if(bmp == null){Log.e(TAG,"通过options获取到的bitmap为空 ===");}int outHeight=options.outHeight;int outWidth= options.outWidth;Log.i(TAG,"通过Options获取到的图片大小"+ "width:"+ outWidth +" height: " + outHeight);}//sd 卡权限动态申请private void checkPermission() {if (ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)!= PackageManager.PERMISSION_GRANTED) {ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},100);}}@Overridepublic void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {if (requestCode == 100) {if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {Log.d(TAG, "");}}}}
log打印：
Android读取不同位置(drawable,asset,sdCard)的图片资源
参考地址：/Jason_996/article/details/48311985
