ImageLoader请求图片

导入依赖:
compile ‘com.nostra13.universalimageloader:universal-image-loader:1.9.5’
加权限：网络及读写权限

布局文件：
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android=“http://schemas.android.com/apk/res/android”
xmlns:app=“http://schemas.android.com/apk/res-auto”
xmlns:tools=“http://schemas.android.com/tools”
android:layout_width=“match_parent”
android:layout_height=“match_parent”
tools:context=".MainActivity">

	    <ImageView
	        android:id="@+id/iv"
	        android:layout_width="300dp"
	        android:layout_height="300dp"
	        android:src="@mipmap/ic_launcher"/>
	
	</android.support.constraint.ConstraintLayout>

创建一个Mapp类并在清单文件下注册
package gj.com.day03_2_imageloader;

	import android.app.Application;
	
	import com.nostra13.universalimageloader.core.ImageLoader;
	import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
	
	public class MApp extends Application {
	    //创建oncreate方法
		
		    @Override
		    public void onCreate() {
		        super.onCreate();
		        //创建ImageLoader的配置类
		        ImageLoaderConfiguration imageLoaderConfiguration = new ImageLoaderConfiguration.Builder(this).build();
		        //ImageLoader的框架实例
		        ImageLoader instance = ImageLoader.getInstance();
		        instance.init(imageLoaderConfiguration);
		
		    }
		}
在application下：
				<application
				     android:name=".MApp"
				     android:allowBackup="true"
				     android:icon="@mipmap/ic_launcher"
				     android:label="@string/app_name"
				     android:roundIcon="@mipmap/ic_launcher_round"
				     android:supportsRtl="true"
				     android:theme="@style/AppTheme">
				     <activity android:name=".MainActivity">
				         <intent-filter>
				             <action android:name="android.intent.action.MAIN" />
				
				             <category android:name="android.intent.category.LAUNCHER" />
				         </intent-filter>
				     </activity>
				 </application>

代码:

		package gj.com.day03_2_imageloader;
		
		import android.support.v7.app.AppCompatActivity;
		import android.os.Bundle;
		import android.widget.ImageView;
		import com.nostra13.universalimageloader.core.ImageLoader;
		
		public class MainActivity extends AppCompatActivity {
		    String urlBitmap = "http://img.my.csdn.net/uploads/201407/26/1406383265_8550.jpg";
		    private ImageView iv;
		
		    @Override
		    protected void onCreate(Bundle savedInstanceState) {
		        super.onCreate(savedInstanceState);
		        setContentView(R.layout.activity_main);
		        //找组件
		        iv = findViewById(R.id.iv);
		        //获取实例
		        ImageLoader instance = ImageLoader.getInstance();
		        //赋值 展示图片
		        instance.displayImage(urlBitmap,iv);
		
		    }
		}