activity_main
界面代码如下
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
tools:context=".MainActivity">
<LinearLayout
android:id="@+id/ll_text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="5dp"
android:layout_marginTop="10dp"
android:orientation="horizontal">
<EditText
android:id="@+id/et_path"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginRight="3dp"
android:layout_weight="1"
android:background="#EBEBEB"
android:hint="请输入图片路径"
android:inputType="textUri"
android:paddingLeft="3dp"
android:textColor="#696969"
android:textSize="20sp" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="4"
android:background="#EBEBEB"
android:onClick="click"
android:text="浏览"
android:textColor="#696969"
android:textSize="20sp" />
</LinearLayout>
<ImageView
android:id="@+id/iv_pic"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@+id/ll_text"
android:scaleType="fitCenter" />
</RelativeLayout>
MainActivity
代码如下
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.text.TextUtils;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
public class MainActivity extends AppCompatActivity {
protected static final int CHANGE_UI = 1;
protected static final int ERROR = 2;
private EditText et_path;
private ImageView ivPic;
// 主线程创建消息处理器
private Handler handler = new Handler() {
public void handleMessage(android.os.Message msg) {
if (msg.what == CHANGE_UI) {
Bitmap bitmap = (Bitmap) msg.obj;
ivPic.setImageBitmap(bitmap);
} else if (msg.what == ERROR) {
Toast.makeText(MainActivity.this, "显示图片错误",
Toast.LENGTH_SHORT).show();
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et_path = (EditText) findViewById(R.id.et_path);
ivPic = (ImageView) findViewById(R.id.iv_pic);
}
public void click(View view) {
final String path = et_path.getText().toString().trim();
if (TextUtils.isEmpty(path)) {
Toast.makeText(this, "图片路径不能为空", Toast.LENGTH_SHORT).show();
} else {
//子线程请求网络,Android4.0以后访问网络不能放在主线程中
new Thread() {
private HttpURLConnection conn;
private Bitmap bitmap;
public void run() {
// 连接服务器 get 请求 获取图片
try {
//创建URL对象
URL url = new URL(path);
// 根据url 发送 http的请求
conn = (HttpURLConnection) url.openConnection();
// 设置请求的方式
conn.setRequestMethod("GET");
//设置超时时间
conn.setConnectTimeout(5000);
// 得到服务器返回的响应码
int code = conn.getResponseCode();
//请求网络成功后返回码是200
if (code == 200) {
//获取输入流
InputStream is = conn.getInputStream();
//将流转换成Bitmap对象
bitmap = BitmapFactory.decodeStream(is);
//将更改主界面的消息发送给主线程
Message msg = new Message();
msg.what = CHANGE_UI;
msg.obj = bitmap;
handler.sendMessage(msg);
} else {
//返回码不等于200 请求服务器失败
Message msg = new Message();
msg.what = ERROR;
handler.sendMessage(msg);
}
} catch (Exception e) {
e.printStackTrace();
Message msg = new Message();
msg.what = ERROR;
handler.sendMessage(msg);
}
//关闭连接
conn.disconnect();
}
}.start();
}
}
}
最后记得给 AndroidManifest中 加上 访问网络的权限
<uses-permission android:name="android.permission.INTERNET"/>
最后打开虚拟机
输入图片地址
https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1576162426696&di=d84e2f38070db06a909401060b047222&imgtype=0&src=http%3A%2F%2Fpic1.zhimg.com%2F50%2Fv2-fe41e8f50ce5a9d096f29585551d02c8_hd.jpg
点击浏览即可