Android View保存为本地图片

ImageView的保存方式和其它View稍微有些不一样

ImageView

    大概思路：获取到ImageView的bitmap数据，将bitmap数据压缩为图片并输出，关闭输出流

//  设置保存路径，现在的路径就是"/storage/emulated/0"目录下的image1.png
  File file = new File(Environment.getExternalStorageDirectory().getAbsolutePath(),"image1.png");
//  获取到ImageView的drawable，并强转为bitmapDrawable
  BitmapDrawable bitmapDrawable = (BitmapDrawable) imageView.getDrawable();
  Bitmap bitmap = bitmapDrawable.getBitmap();//bitmapDrawable转换为bitmap
//  判断是不是获取到了bitmap
  if (bitmap != null){
//    输出流需要捕获异常
      try {
//        输出流
          FileOutputStream fileOutputStream = new FileOutputStream(file);
          // CompressFormat: 压缩格式，png、jpg、webp等
          // quality: 图片质量，0-100
          // OutputStream: 输出流
          bitmap.compress(Bitmap.CompressFormat.PNG,100,fileOutputStream);
          fileOutputStream.flush(); //清空io
      } catch (IOException e) {
          e.printStackTrace();
      } finally {
          if (file.exists()){
              Toast.makeText(getContext(),"保存成功",Toast.LENGTH_SHORT).show();
          }
          else {
              Toast.makeText(getContext(),"保存失败",Toast.LENGTH_SHORT).show();
          }
      }
  }
  else {
      Toast.makeText(getContext(),"保存失败",Toast.LENGTH_SHORT).show();
  }

其它View

    其它View无法像ImageView那样通过getDrawable获取drawable并强转为bitmapDrawable，然后再转换为bitmap并保存；必须给View创建一个bitmap，然后将画面绘制在bitmap中

//设置保存路径，现在的路径就是"/storage/emulated/0"目录下的image2.png
  File file = new File(Environment.getExternalStorageDirectory().getAbsolutePath(),"image2.png");
//  获取它的宽高，用于定义创建的bitmap的宽高
  int w = pagerView.getWidth();
  int h = pagerView.getHeight();
  // width: bitmap的宽
  // height: bitmap的高
  // Config: bitmap的画质，ARGB_8888代表32位ARGB位图，最高画质
  Bitmap bitmap = Bitmap.createBitmap(w,h, Bitmap.Config.ARGB_8888);
//  向bitmap中绘制View中的控件，否则保存为一片空白
  Canvas canvas = new Canvas(bitmap);
  canvas.drawColor(Color.WHITE);//设置canvas画布颜色，默认为透明
  pagerView.layout(0,0,w,h);//剪裁View，左边开始位置、顶部开始位置、右边结束位置、底部结束位置
  pagerView.draw(canvas);//将view画到canvas中
  
//  然后和正常流程一样了
  try {
      FileOutputStream fileOutputStream = new FileOutputStream(file);
      bitmap.compress(Bitmap.CompressFormat.PNG,100,fileOutputStream);
      fileOutputStream.flush();
  } catch (IOException e) {
      e.printStackTrace();
  } finally {
      if (file.exists()){
          Toast.makeText(getContext(),"保存成功",Toast.LENGTH_SHORT).show();
      }
      else {
          Toast.makeText(getContext(),"保存失败",Toast.LENGTH_SHORT).show();
      }
  }

    不要忘记赋予储存读写权限

附，Android文件复制

    读取后直接写入，读多少，写多少，简单粗暴

//  源文件路径和目标文件路径
  File file1 = new File(Environment.getExternalStorageDirectory().getAbsolutePath(),"image2.png");
  File file2 = new File(Environment.getExternalStorageDirectory().getAbsolutePath(),"image3.png");
  FileInputStream fileInputStream = null;
  FileOutputStream fileOutputStream = null;
  try {
      fileInputStream = new FileInputStream(file1);
      fileOutputStream = new FileOutputStream(file2);
//      字节流
      byte[] bytes = new byte[1024];
      int len;//剩余长度
      while ((len = fileInputStream.read(bytes)) > 0){
          fileOutputStream.write(bytes,0,len);//直接写入
      }
      fileOutputStream.flush();//清空io
  } catch (IOException e) {
      e.printStackTrace();
  } finally {
      if (file2.exists()){
          Toast.makeText(getContext(),"复制成功",Toast.LENGTH_SHORT).show();
      }
      else {
          Toast.makeText(getContext(),"复制失败",Toast.LENGTH_SHORT).show();
      }

      if (fileInputStream != null || fileOutputStream != null){
          try {
              fileInputStream.close();
              fileOutputStream.close();
          } catch (IOException e) {
              e.printStackTrace();
          }
      }
  }