Android（九）
其他
2020-04-21 09:08:17
阅读次数: 0
一、互联网连接（需要联网）
- 代码
Button btn=(Button) findViewById(R.id.button1);
btn.setOnClickListener(new OnClickListener( ) {
public void onClick(View arg0) {
new AsyncTask<String, Void, Void>(){//异步任务，在后台执行
protected Void doInBackground(String... arg0) {
// 准备一个url对象
try {
URL url=new URL(arg0[0]);
//获取互联网连接
URLConnection connection=url.openConnection();
//获取服务器返回的数据
InputStream is=connection.getInputStream();
//打开数据
InputStreamReader isr=new InputStreamReader(is,"utf-8");
//读取数据
BufferedReader br=new BufferedReader(isr);
String line;//按行读
//当读的行不为空，就一直读，直到结束
while((line=br.readLine())!=null){
System.out.println(line);
}
br.close();
isr.close();
is.close();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
}.execute("https://www.baidu.com");
}
});
- 配置权限
<uses-permission android:name="android.permission.INTERNET"/>
二、根据图片地址在app内加载一张图片
- 获取图片资源
public class GetHtmlData {
//1.获取图片资源方法
public static byte[] getImage(String path) throws Exception{
URL url=new URL(path);
HttpURLConnection connection=(HttpURLConnection) url.openConnection();
//设置一个访问超时时间
connection.setConnectTimeout(6000);//单位为毫秒，这里设为6秒
//设置请求类型
connection.setRequestMethod("GET");
//判断访问网络的状态码
if(connection.getResponseCode()!=200){
throw new RuntimeException("请求失败");
}
//获取内容
InputStream is=connection.getInputStream();
//使用专门解析字节码的函数
byte [] bt=StreamTool.read(is);
is.close();
return bt;
}
public static String getHtml(String path) throws Exception{
//2.获得网页的方法
URL url=new URL(path);
HttpURLConnection connection=(HttpURLConnection) url.openConnection();
//设置一个访问超时时间
connection.setConnectTimeout(6000);//单位为毫秒，这里设为6秒
//设置请求类型
connection.setRequestMethod("GET");
//判断访问网络的状态码
if(connection.getResponseCode()==200){//成功访问后，要干的内容
InputStream is=connection.getInputStream();
byte [] data=StreamTool.read(is);
String html=new String(data,"utf-8");
return html;
}
return null;
}
}
- 设置解析数据流的工具
public class StreamTool {//用来解析数据流的工具
public static byte[] read(InputStream inputStream) throws Exception{
ByteArrayOutputStream outputStream=new ByteArrayOutputStream();
byte[] buffer=new byte[1024];
int len=0;
while((len=inputStream.read(buffer))!=-1){
outputStream.write(buffer,0,len);
}
inputStream.close();
return outputStream.toByteArray();
}
}
- 设置权限
<uses-permission android:name="android.permission.INTERNET"/>
- 设置布局界面并获取图片
public class MainActivity extends Activity {
private TextView textMenu;
private TextView textShow;
private ScrollView scroll;
private ImageView imgpic;
private Bitmap bitmap;
private WebView webView;
private String Image_Url="https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1564466297038&di=ec5942c876dfe1f366608b01746cfa91&imgtype=0&src=http%3A%2F%2Fwx2.sinaimg.cn%2Flarge%2F006agyVmly1g5ftv14rwlj30u01bogzi.jpg";
private String detail="";
private String Html_Url="https://www.baidu.com";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textShow=(TextView) findViewById(R.id.textShow);
textMenu=(TextView)findViewById(R.id.textMenu);
imgpic=(ImageView)findViewById(R.id.imgpic);
scroll=(ScrollView)findViewById(R.id.scroll);
webView=(WebView) findViewById(R.id.webView1);
registerForContextMenu(textMenu);
}
@Override
public void onCreateContextMenu(ContextMenu menu, View v,
ContextMenuInfo menuInfo) {
MenuInflater inflater=new MenuInflater(this);
inflater.inflate(R.menu.menus, menu);
super.onCreateContextMenu(menu, v, menuInfo);
}
//选择上下文菜单后执行的东西
@Override
public boolean onContextItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.one:
//从网络中加载图片，显示到自己的界面
new Thread(){//开启新线程
public void run(){
try{
byte[] data=GetHtmlData.getImage(Image_Url);
bitmap=BitmapFactory.decodeByteArray(data,0, data.length);
}catch(Exception e){
e.printStackTrace();
}
//System.out.println("1111111111111111111111"+bitmap);
handler.sendEmptyMessage(0x001);
/*hideAll();
imgpic.setVisibility(View.VISIBLE);
imgpic.setImageBitmap(bitmap);*/
}
}.start();
break;
case R.id.two://获取网络地址的html代码
new Thread(){
public void run(){
try {
detail=GetHtmlData.getHtml(Html_Url);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//告诉主程序处理这里
handler.sendEmptyMessage(0x002);//这里是可以随便写一个特征，如0x002
}
}.start();
break;
case R.id.three://根据已经获取的html来获取网页
if(detail.equals("")){
Toast.makeText(getApplicationContext(), "先获取网页在说", 1).show();
}else{
handler.sendEmptyMessage(0x003);
}
break;
default:
break;
}
return super.onContextItemSelected(item);
}
//隐藏所有层次
private void hideAll(){
imgpic.setVisibility(View.GONE);
scroll.setVisibility(View.GONE);
webView.setVisibility(View.GONE);
}
//写个函数用来刷新界面来显示相关的东西
private Handler handler=new Handler(){
public void handleMessage(android.os.Message msg){
switch (msg.what) {
case 0x001:
hideAll();
imgpic.setVisibility(View.VISIBLE);
imgpic.setImageBitmap(bitmap);
break;
case 0x002:
hideAll();
scroll.setVisibility(View.VISIBLE);//显示
textShow.setText(detail);
Toast.makeText(getApplicationContext(), "已获取网页", 1).show();
break;
case 0x003:
hideAll();
webView.setVisibility(View.VISIBLE);
webView.loadDataWithBaseURL("", detail, "text/html", "utf-8", "");
Toast.makeText(getApplicationContext(), "网页已加载完毕", 1).show();
break;
default:
break;
}
}
};
}
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转载自blog.csdn.net/id__39/article/details/105196572
