Merge pull request #2606 from ZhuHongen/master

#6 #899 第六次实验

soft1614080902146/app/src/main/java/com/example/hzu/myapplication/ImgUtils.java

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+package com.example.administrator.myapplication;
+
+import android.content.Context;
+import android.content.Intent;
+import android.graphics.Bitmap;
+import android.net.Uri;
+import android.os.Environment;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+
+
+public class ImgUtils {
+    //保存文件到指定路径
+    public static boolean saveImageToGallery(Context context, Bitmap bmp) {
+        // 首先保存图片
+        String storePath = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "demo";
+        File appDir = new File(storePath);
+        if (!appDir.exists()) {
+            appDir.mkdir();
+        }
+        String fileName = System.currentTimeMillis() + ".jpg";
+        File file = new File(appDir, fileName);
+        try {
+            FileOutputStream fos = new FileOutputStream(file);
+            //通过io流的方式来压缩保存图片
+            boolean isSuccess = bmp.compress(Bitmap.CompressFormat.JPEG, 60, fos);
+            fos.flush();
+            fos.close();
+
+            //把文件插入到系统图库
+            //MediaStore.Images.Media.insertImage(context.getContentResolver(), file.getAbsolutePath(), fileName, null);
+
+            //保存图片后发送广播通知更新数据库
+            Uri uri = Uri.fromFile(file);
+            context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, uri));
+            if (isSuccess) {
+                return true;
+            } else {
+                return false;
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        return false;
+    }
+}

soft1614080902146/app/src/main/java/com/example/hzu/myapplication/ThirdActivity.java

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+package com.example.administrator.myapplication;
+
+import android.Manifest;
+import android.content.Context;
+import android.content.Intent;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.os.Build;
+import android.os.Bundle;
+import android.os.Handler;
+import android.os.Message;
+import android.support.v7.app.AppCompatActivity;
+import android.util.Log;
+import android.view.View;
+import android.widget.Button;
+import android.widget.EditText;
+import android.widget.ImageView;
+import android.widget.Toast;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.List;
+
+import pub.devrel.easypermissions.AppSettingsDialog;
+import pub.devrel.easypermissions.EasyPermissions;
+
+
+public class ThirdActivity extends AppCompatActivity implements EasyPermissions.PermissionCallbacks {
+
+    private static final int REQUEST_CODE_SAVE_IMG = 10;
+    private static final String TAG = "MainActivity";
+    private Context mContext;
+    private EditText editText;
+    private Button button;
+    private Button button1;
+    private ImageView imageView;
+    private Bitmap bitmap;
+    //手柄更新的作用
+    Handler handler=new Handler(){
+        public void handleMessage(Message msg) {
+            if(msg.what==111){
+                imageView.setImageBitmap(bitmap);
+            }
+        };
+    };
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_third);
+        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
+        //初始化组件
+        editText=(EditText) findViewById(R.id.editText2);
+        button=(Button) findViewById(R.id.download);
+        button1=(Button)findViewById(R.id.save) ;
+        imageView=(ImageView) findViewById(R.id.imageView);
+
+        mContext = this;
+        button.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                new Thread(t).start();
+
+            }
+        });
+        button1.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                requestPermission();
+            }
+        });
+    }
+
+    //为了下载图片资源，开辟一个新的子线程
+    Thread t=new Thread() {
+        public void run() {
+            //下载图片的路径
+            String iPath = editText.getText().toString();
+            try {
+                //对资源链接
+                URL url = new URL(iPath);
+                //打开输入流
+                InputStream inputStream = url.openStream();
+                //对网上资源进行下载转换位图图片
+                bitmap = BitmapFactory.decodeStream(inputStream);
+                handler.sendEmptyMessage(111);
+                inputStream.close();
+            }catch (MalformedURLException e){
+                e.printStackTrace();
+            }catch (IOException e){
+                e.printStackTrace();
+            }
+        }
+    };
+    /**
+     * 请求读取sd卡的权限
+     */
+    private void requestPermission() {
+        if (Build.VERSION.SDK_INT >= 23) {
+            //读取sd卡的权限
+            String[] mPermissionList = new String[]{Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE};
+            if (EasyPermissions.hasPermissions(mContext, mPermissionList)) {
+                //已经同意过
+                saveImage(bitmap);
+            } else {
+                //未同意过,或者说是拒绝了，再次申请权限
+                EasyPermissions.requestPermissions(
+                        this,  //上下文
+                        "保存图片需要读取sd卡的权限", //提示文言
+                        REQUEST_CODE_SAVE_IMG, //请求码
+                        mPermissionList //权限列表
+                );
+            }
+        } else {
+            saveImage(bitmap);
+        }
+    }
+
+
+    //保存图片
+    private void saveImage(Bitmap bitmap) {
+
+        boolean isSaveSuccess = ImgUtils.saveImageToGallery(mContext, bitmap);
+        if (isSaveSuccess) {
+            Toast.makeText(mContext, "保存图片成功", Toast.LENGTH_SHORT).show();
+        } else {
+            Toast.makeText(mContext, "保存图片失败，请稍后重试", Toast.LENGTH_SHORT).show();
+        }
+    }
+
+    //授权结果，分发下去
+    @Override
+    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
+        // Forward results to EasyPermissions
+        //跳转到onPermissionsGranted或者onPermissionsDenied去回调授权结果
+        EasyPermissions.onRequestPermissionsResult(requestCode, permissions, grantResults, this);
+    }
+
+
+    //同意授权
+    @Override
+    public void onPermissionsGranted(int requestCode, List<String> list) {
+        Log.i(TAG, "onPermissionsGranted:" + requestCode + ":" + list.size());
+        saveImage(bitmap);
+    }
+
+    //拒绝授权
+    @Override
+    public void onPermissionsDenied(int requestCode, List<String> perms) {
+        Log.i(TAG, "onPermissionsDenied:" + requestCode + ":" + perms.size());
+        if (EasyPermissions.somePermissionPermanentlyDenied(this, perms)) {
+            //打开系统设置，手动授权
+            new AppSettingsDialog.Builder(this).build().show();
+        }
+    }
+
+    @Override
+    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
+        super.onActivityResult(requestCode, resultCode, data);
+        if (requestCode == AppSettingsDialog.DEFAULT_SETTINGS_REQ_CODE) {
+            //拒绝授权后，从系统设置了授权后，返回APP进行相应的操作
+            Log.i(TAG, "onPermissionsDenied:------>自定义设置授权后返回APP");
+            saveImage(bitmap);
+        }
+    }
+}

soft1614080902146/app/src/main/res/layout/activity_third.xml

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+<?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=".ThirdActivity">
+
+
+    <ImageView
+        android:id="@+id/imageView"
+        android:layout_width="352dp"
+        android:layout_height="347dp"
+        android:layout_marginBottom="28dp"
+        android:layout_marginEnd="3dp"
+        android:layout_marginLeft="2dp"
+        android:layout_marginRight="3dp"
+        android:layout_marginStart="2dp"
+        android:layout_marginTop="50dp"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintHorizontal_bias="0.507"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/download" />
+
+    <Button
+        android:id="@+id/download"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginLeft="86dp"
+        android:layout_marginStart="86dp"
+        android:layout_marginTop="16dp"
+        android:text="下载"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/editText2" />
+
+    <EditText
+        android:id="@+id/editText2"
+        android:layout_width="363dp"
+        android:layout_height="wrap_content"
+        android:layout_marginEnd="11dp"
+        android:layout_marginLeft="10dp"
+        android:layout_marginRight="11dp"
+        android:layout_marginStart="10dp"
+        android:layout_marginTop="16dp"
+        android:ems="10"
+        android:hint="输入网址"
+        android:inputType="textPersonName"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintVertical_chainStyle="spread" />
+
+    <Button
+        android:id="@+id/save"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginEnd="84dp"
+        android:layout_marginRight="84dp"
+        android:text="保存"
+        app:layout_constraintBaseline_toBaselineOf="@+id/download"
+        app:layout_constraintEnd_toEndOf="parent" />
+
+
+</android.support.constraint.ConstraintLayout>

soft1614080902146/report6.md

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+### 实验六
+
+## 一.实验目的
+
+掌握Android网络访问方法；
+
+## 二.实验内容
+
+从网络下载一个文件（图片、MP3、MP4）；
+保存到手机，在应用中使用文件；
+将应用运行结果截图。
+
+## 三.实验步骤
+
+1.先修改AndroidManifest.xml获取相关的权限
+2.写一个工具类imgUtils，调用它可以保存图片到本地相册.
+3.开辟线程下载图片,将图片转换成位图送给imageView,调用requestPermission获取权限，通过后调用saveImage保存图片到本地相册.
+4.使用下载按钮获取URL的图片，点击保存保存图片到本地
+5.使用Git将代码提交到自己的库中：https://github.com/PickForSth/android-labs-2018
+
+   $ git pull origin master<br>
+   $ git add soft16130905022146<br>
+   $ git commit "#5 #1370第6次实验"<br>
+   $ git push<br>
+6.在GitHub中使用Markdown文件编写实验报告（report6.md）.
+7.在自己的GitHub库上创建和发送Pull Request（注意查看Changed files）.
+
+## 四.实验截图
+
+![image](https://github.com/ZhuHongen/android-labs-2018/blob/master/soft1614080902146/report61.JPG)
+
+![image](https://github.com/ZhuHongen/android-labs-2018/blob/master/soft1614080902146/report62.JPG)
+
+![image](https://github.com/ZhuHongen/android-labs-2018/blob/master/soft1614080902146/report63.JPG)
+## 五.实验体会
+
+通过这次实验使我更加熟悉git和android studio,为App加一个menu，利用toolbar实现Activity间的切换，开辟线程获取URL进而获取网上的资源文件