<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

package zhangphil.test;
 
import android.app.Activity;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.os.Environment;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.util.DisplayMetrics;
import android.view.View;
import android.widget.Toast;
 
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
 
public class JavaActivity extends AppCompatActivity {
 
  @Override
  protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.drawable_activity);
 
    AppCompatActivity activity = this;
 
    findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "zhangphil.jpg");
        Bitmap bitmap = screenShot(activity);
        try {
          if (!file.exists())
            file.createNewFile();
 
          boolean ret = save(bitmap, file, Bitmap.CompressFormat.JPEG, true);
          if (ret) {
            Toast.makeText(getApplicationContext(), "截圖已保持至 " + file.getAbsolutePath(), Toast.LENGTH_SHORT).show();
          }
        } catch (Exception e) {
          e.printStackTrace();
        }
      }
    });
  }
 
  /**
   * 保存圖片到文件File。
   *
   * @param src   源圖片
   * @param file  要保存到的文件
   * @param format 格式
   * @param recycle 是否回收
   * @return true 成功 false 失敗
   */
  public static boolean save(Bitmap src, File file, Bitmap.CompressFormat format, boolean recycle) {
    if (isEmptyBitmap(src))
      return false;
 
    OutputStream os;
    boolean ret = false;
    try {
      os = new BufferedOutputStream(new FileOutputStream(file));
      ret = src.compress(format, 100, os);
      if (recycle && !src.isRecycled())
        src.recycle();
    } catch (IOException e) {
      e.printStackTrace();
    }
 
    return ret;
  }
 
 
  /**
   * 獲取當前屏幕截圖，不包含狀態(tài)欄（Status Bar）。
   *
   * @param activity activity
   * @return Bitmap
   */
  public static Bitmap screenShot(Activity activity) {
    View view = activity.getWindow().getDecorView();
    view.setDrawingCacheEnabled(true);
    view.buildDrawingCache();
    Bitmap bmp = view.getDrawingCache();
    int statusBarHeight = getStatusBarHeight(activity);
    int width = (int) getDeviceDisplaySize(activity)[0];
    int height = (int) getDeviceDisplaySize(activity)[1];
 
    Bitmap ret = Bitmap.createBitmap(bmp, 0, statusBarHeight, width, height - statusBarHeight);
    view.destroyDrawingCache();
 
    return ret;
  }
 
  public static float[] getDeviceDisplaySize(Context context) {
    Resources resources = context.getResources();
    DisplayMetrics dm = resources.getDisplayMetrics();
    int width = dm.widthPixels;
    int height = dm.heightPixels;
 
    float[] size = new float[2];
    size[0] = width;
    size[1] = height;
 
    return size;
  }
 
  public static int getStatusBarHeight(Context context) {
    int height = 0;
    int resourceId = context.getResources().getIdentifier("status_bar_height", "dimen", "android");
    if (resourceId > 0) {
      height = context.getResources().getDimensionPixelSize(resourceId);
    }
 
    return height;
  }
 
  /**
   * Bitmap對象是否為空。
   */
  public static boolean isEmptyBitmap(Bitmap src) {
    return src == null || src.getWidth() == 0 || src.getHeight() == 0;
  }
}