涉及到的內(nèi)容 ：

1塌西、圖片剪切，2筝尾、圖片保存到SD卡 3捡需、文件讀取和保存 4、自定義View 繪制平滑曲線(xiàn)
5筹淫、RecycleView 顯示 6站辉、Glide框架顯示圖片 7、大圖片顯示 8、從相冊(cè)選擇圖片

所用設(shè)備：

三星 華為 平板

目錄結(jié)構(gòu)

目錄結(jié)構(gòu)

Utils封裝

1.權(quán)限檢查

 

import android.Manifest;
import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.os.Build;
import android.support.v4.app.ActivityCompat;
import android.util.Log;

public class CheckPermissionsUtil {
    private static final String TAG = " fuck";
    Context mContext;

    public CheckPermissionsUtil(Context mContext) {
        this.mContext = mContext;
    }
    private String[] needPermissions = {
            Manifest.permission.READ_EXTERNAL_STORAGE,
            Manifest.permission.MOUNT_UNMOUNT_FILESYSTEMS,
            Manifest.permission.WRITE_EXTERNAL_STORAGE

    };

    private boolean checkPermission(String... needPermissions) {
        for (String permission : needPermissions) {
            if (ActivityCompat.checkSelfPermission(mContext, permission) != PackageManager.PERMISSION_GRANTED) {
                return false;
            }
        }
        return true;
    }

    private void requestPermission(Activity activity, int code, String... needPermissions) {
        ActivityCompat.requestPermissions(activity, needPermissions, code);
        Log.i(TAG, "request Permission...");
    }
    public void requestAllPermission(Activity activity) {
        if (Build.VERSION.SDK_INT >= 23) {
            Log.i(TAG, "request All Permission...");
            for (String permission : needPermissions) {
                if (!checkPermission(permission)) {
                    requestPermission(activity, 0, permission);
                }
            }
        }
    }
}

調(diào)用流程

     CheckPermissionsUtil checkPermissionsUtil = new CheckPermissionsUtil(this);
     checkPermissionsUtil.requestAllPermission(this);

2.調(diào)用系統(tǒng)圖片剪切

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.net.Uri;

/**
 * Created by Administrator on 2017/5/5 0005.
 * 圖片裁剪
 */

public class CutUitl {


    public static Uri Ucrop(Uri uri, Activity activity) {
        // 裁剪圖片
        Intent intent = new Intent("com.android.camera.action.CROP");
        intent.setDataAndType(uri, "image/*");
        intent.putExtra("crop", "true");
        intent.putExtra("aspectX", 800);
        intent.putExtra("aspectY", 1000);

        intent.putExtra("scale", true);
        intent.putExtra("return-data", true);
        intent.putExtra(MediaStore.EXTRA_OUTPUT, uri);
        intent.putExtra("outputFormat", Bitmap.CompressFormat.JPEG.toString());
        intent.putExtra("FaceDetection", true); //  face detection
        activity.startActivityForResult(intent, 200);

        return uri;
    }


    public static void UcropNoUri(Uri uri, Activity activity) {
        // 裁剪圖片
        if(null == uri){
            return;
        }

        Intent intent = new Intent();
        intent.setAction("com.android.camera.action.CROP");
        intent.setDataAndType(uri, "image/*");// mUri是已經(jīng)選擇的圖片Uri
        intent.putExtra("crop", "true");
        intent.putExtra("aspectX", 800);
        intent.putExtra("aspectY", 1000);
        intent.putExtra("scale", true);
        intent.putExtra("return-data", true);
        activity.startActivityForResult(intent, 200);


    }

}

3.文件讀取和存儲(chǔ)

import android.content.Context;
import android.graphics.Bitmap;
import android.os.Environment;
import android.text.TextUtils;
import android.util.Log;
import android.widget.Toast;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.RandomAccessFile;

import cn.forward.androids.utils.ImageUtils;

/**
 * 文件讀取和保存
 */

public class FileUtil {

    /*存儲(chǔ)過(guò)的文件名路徑*/
    private static String SAVEPATH = "/sdcard/DCIM/savealva/";
    private static final String SAVEFILENAME = "save.txt";
    /*存儲(chǔ)對(duì)應(yīng)坐標(biāo)和文件*/
    private static String PATH = "/sdcard/DCIM/alva/";

    private static final String TAG = "zhangxin";
    private static String strContent;

    private static File files = null;
    private static File file = null;
    private static String strFilePath;



    public static void writeTxtToFile(String strcontent,String name,String path) {


            //生成文件夾之后饰剥，再生成文件殊霞，不然會(huì)出錯(cuò)
            makeFilePath(path, name);
            strFilePath = path + name;
        // 每次寫(xiě)入時(shí)，都換行寫(xiě)
        strContent = strcontent + "\r\n";
        try {
            File file = new File(strFilePath);
            if (!file.exists()) {
                Log.e(TAG, "輸出信息-->: " + strFilePath);
                file.getParentFile().mkdirs();
                file.createNewFile();
            }
            RandomAccessFile raf = new RandomAccessFile(file, "rwd");
            raf.seek(file.length());
            raf.write(strContent.getBytes());

            raf.close();

        } catch (Exception e) {
            Log.e(TAG, "輸出信息-->: " + e.getMessage());
        }
    }

    /**
     * @param fileName
     * @return
     * @throws IOException
     * @desc 讀取sd卡文件內(nèi)容
     */
    public static String readSDCard(String fileName) throws IOException {
        // File file = new File(Environment.getExternalStorageDirectory(),fileName);
        File file = new File(fileName);
        FileInputStream fis = new FileInputStream(file);
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int len = 0;
        while ((len = fis.read(buffer)) != -1) {
            bos.write(buffer, 0, len);
        }
        byte[] data = bos.toByteArray();
        fis.close();
        bos.close();

        return new String(data);
    }

    // 生成文件
    public static File makeFilePath(String filePath, String fileName) {
        File file = null;
        makeRootDirectory(filePath);
        try {
            file = new File(filePath + fileName);
            if (!file.exists()) {
                file.createNewFile();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return file;
    }

    // 生成文件夾
    public static void makeRootDirectory(String filePath) {
        File file = null;
        try {
            file = new File(filePath);
            if (!file.exists()) {
                file.mkdir();
            }
        } catch (Exception e) {
            Log.i("error:", e + "");
        }
    }

    //吐司
    public static void Toast(Context context, String str) {
        Toast.makeText(context, str, Toast.LENGTH_SHORT).show();
    }


    //保存圖片
    public static void SaveImage(String savePath, boolean isDir, String name, Bitmap bitmap, Context context) {


        File files = null;
        File file = null;

        if (TextUtils.isEmpty(savePath)) {
            File dcimFile = new File(Environment.getExternalStorageDirectory(), "Alva");
            files = new File(dcimFile, "zx");
            //　保存的路徑
            //   file = new File(files, System.currentTimeMillis() + ".jpg");
            file = new File(files, name);
        } else {
            if (isDir) {
                files = new File(savePath);
                //　保存的路徑
                //file = new File(files, System.currentTimeMillis() + ".jpg");
                file = new File(files, name);
            } else {
                file = new File(savePath);
                files = file.getParentFile();
            }
        }
        files.mkdirs();

        FileOutputStream outputStream = null;
        try {
            outputStream = new FileOutputStream(file);
            bitmap.compress(Bitmap.CompressFormat.JPEG, 100, outputStream);
            ImageUtils.addImage(context.getContentResolver(), file.getAbsolutePath());

        } catch (Exception e) {
            e.printStackTrace();

        } finally {
            if (outputStream != null) {
                try {
                    outputStream.close();

                } catch (IOException e) {
                }
            }
        }

    }


}