首先需要添加权限,同时动态检测读写权限(如果未开启读写权限，则不会触发截屏的监听)：
<!-- 用于监听裁剪之后的图片库的动态 -->
<uses-permission android:name="MediaStore.Images.Media.INTERNAL_CONTENT_URI" />
<uses-permission android:name="MediaStore.Images.Media.EXTERNAL_CONTENT_URI" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
一、核心类：ScreenShotManager
public class ScreenShotManager {
private Context mContext;
public static final String TAG = "ScreenShotManager";
private ContentObserver mInternalObserver; //内部存储器内容观察者
private ContentObserver mExternalObserver; //外部存储器内容观察者
//匹配各个手机截屏路径的关键字
private static final String[] KEYWORDS = {
"screenshot", "screenshots", "screen_shot", "screen-shot", "screen shot",
"screencapture", "screen_capture", "screen-capture", "screen capture",
"screencap", "screen_cap", "screen-cap", "screen cap", "截屏"
};
//读取媒体数据库时需要读取的列
private static final String[] MEDIA_PROJECTIONS = {
MediaStore.Images.ImageColumns.DATA,
MediaStore.Images.ImageColumns.DATE_TAKEN,
};
public ScreenShotManager(final Context context) {
mContext = context;
initManager();
}
/**
* 初始化
*/
private void initManager() {
if (mContext == null) {
return;
}
final Handler handler = new Handler(mContext.getMainLooper());
mInternalObserver = new MediaContentObserver(MediaStore.Images.Media.INTERNAL_CONTENT_URI, handler);
mExternalObserver = new MediaContentObserver(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, handler);
}
/**
* 添加监听
*/
public void startListener() {
if (mContext == null) {
return;
}
mContext.getContentResolver().registerContentObserver(MediaStore.Images.Media.INTERNAL_CONTENT_URI, false, mInternalObserver);
mContext.getContentResolver().registerContentObserver(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, false, mExternalObserver);
}
/**
* 注销监听
*/
public void stopListener() {
if (mContext == null) {
return;
}
mContext.getContentResolver().unregisterContentObserver(mInternalObserver);
mContext.getContentResolver().unregisterContentObserver(mExternalObserver);
}
/**
* 检查是否大于当前时间五秒(兼容小米)，是则舍弃，反之亦然
*
* @param dateTime 图片保存时间
* @return true 符合预期
*/
private boolean checkTime(final long dateTime) {
return System.currentTimeMillis() - dateTime < 5 * 1000;
}
/**
* 判断是否是截屏
*/
private boolean checkScreenShot(String data) {
data = data.toLowerCase();
// 判断图片路径是否含有指定的关键字之一, 如果有, 则认为当前截屏了
for (String keyWork : KEYWORDS) {
if (data.contains(keyWork)) {
return true;
}
}
return false;
}
/**
* 处理监听到的事件(当图片库发生变化是会触发)
*
* @param contentUri contentUri
*/
private void handleMediaContentChange(Uri contentUri) {
Cursor cursor = null;
try {
// 数据改变时查询数据库中最后加入的一条数据
cursor = mContext.getContentResolver().query(
contentUri,
MEDIA_PROJECTIONS,
null,
null,
MediaStore.Images.ImageColumns.DATE_ADDED + " desc limit 1"
);
if (cursor == null) {
return;
}
if (!cursor.moveToFirst()) {
return;
}
// 获取各列的索引
int dataIndex = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
int dataData = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATE_TAKEN);
// 获取行数据
String data = cursor.getString(dataIndex);
long dateTime = cursor.getLong(dataData);
// 处理获取到的第一行数据
if (checkTime(dateTime)) {
handleMediaRowData(data);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (cursor != null && !cursor.isClosed()) {
cursor.close();
}
}
}
/**
* 处理监听到的资源
*/
private void handleMediaRowData(String data) {
if (checkScreenShot(data)) {
if (TextUtils.isEmpty(data)) {
return;
}
Intent intent = new Intent(mContext, ShotShareActivity.class);
intent.putExtra("snapshot_path", data);
mContext.startActivity(intent);
} else {
Log.e(TAG, "Not screenshot event:" + data);
}
}
/**
* 媒体内容观察者(观察媒体数据库的改变)
*/
private class MediaContentObserver extends ContentObserver {
private Uri mContentUri;
MediaContentObserver(Uri contentUri, Handler handler) {
super(handler);
mContentUri = contentUri;
}
@Override
public void onChange(boolean selfChange) {
super.onChange(selfChange);
new Thread(new Runnable() {
@Override
public void run() {
handleMediaContentChange(mContentUri);
}
}).start();
}
}
}
二、截屏展示界面
public class ShotShareActivity extends AppCompatActivity {
private ImageView ivContent;
private int count;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_shot_share);
String originPath = getIntent().getStringExtra("snapshot_path");
initIvContent(originPath);
}
private void initIvContent(String path) {
ivContent = findViewById(R.id.iv_content);
//状态栏的高度
int statusHeight = Utils.getStatusBarHeight(this);
//虚拟导航栏的高度
int navHeight = Utils.getNavigationBarHeight(this);
float width = Utils.getScreenWidth(this) - Utils.dp2px(this, 116);
float ratio = (float) Utils.div(Utils.getScreenWidth(this), Utils.getScreenHeight(this) - statusHeight - navHeight, 2);
float height = width / ratio;
RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
layoutParams.height = (int) height;
ivContent.setLayoutParams(layoutParams);
//魅族手机生成的截图文件带有 "-" 的命名，会导致获取bitmap为null。利用Glide生成的bitmap
loadImage(path, statusHeight, navHeight);
}
/**
* 加载截屏文件，为了防止加载失败，可以重复加载(最多5次)
*
* @param path 截屏文件路径
* @param statusHeight 状态栏高度
* @param navHeight 虚拟导航栏高度
*/
private void loadImage(final String path, final int statusHeight, final int navHeight) {
Glide.with(this).asBitmap().load(path).into(new SimpleTarget<Bitmap>() {
@Override
public void onResourceReady(Bitmap resource, Transition<? super Bitmap> transition) {
//源文件生成的bitmap
//裁剪bitmap,去掉状态栏和底部的菜单栏(x+width must be < bitmap.width())
try {
Bitmap resultBitmap = Bitmap.createBitmap(resource, 0, statusHeight, resource.getWidth(), resource.getHeight() - statusHeight - navHeight);
ivContent.setImageBitmap(resultBitmap);
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
public void onLoadFailed(Drawable errorDrawable) {
super.onLoadFailed(errorDrawable);
//加载失败的情况下重新加载一次,最多加载五次
if (count <= 5) {
count = count + 1;
loadImage(path, statusHeight, navHeight);
}
}
});
}
}
三、Util类
public class Utils {
/**
* Return the width of screen, in pixel.
*
* @return the width of screen, in pixel
*/
public static int getScreenWidth(Context context) {
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
if (wm == null) {
return context.getResources().getDisplayMetrics().widthPixels;
}
Point point = new Point();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
wm.getDefaultDisplay().getRealSize(point);
} else {
wm.getDefaultDisplay().getSize(point);
}
return point.x;
}
/**
* Return the height of screen, in pixel.
*
* @return the height of screen, in pixel
*/
public static int getScreenHeight(Context context) {
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
if (wm == null) {
return context.getResources().getDisplayMetrics().heightPixels;
}
Point point = new Point();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
wm.getDefaultDisplay().getRealSize(point);
} else {
wm.getDefaultDisplay().getSize(point);
}
return point.y;
}
/**
* 获取状态栏高度
*
* @param context context
* @return 状态栏高度
*/
public static int getStatusBarHeight(Context context) {
// 获得状态栏高度
int resourceId = context.getResources().getIdentifier("status_bar_height", "dimen", "android");
return context.getResources().getDimensionPixelSize(resourceId);
}
/**
* 虚拟导航栏是否显示
*
* @param activity activity
* @return boolean
*/
private static boolean isNavigationBarShow(Activity activity) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
Display display = activity.getWindowManager().getDefaultDisplay();
Point size = new Point();
Point realSize = new Point();
display.getSize(size);
display.getRealSize(realSize);
return realSize.y != size.y;
} else {
boolean menu = ViewConfiguration.get(activity).hasPermanentMenuKey();
boolean back = KeyCharacterMap.deviceHasKey(KeyEvent.KEYCODE_BACK);
if (menu || back) {
return false;
} else {
return true;
}
}
}
/**
* 获取虚拟导航栏的高度
*
* @param activity activity
* @return int
*/
public static int getNavigationBarHeight(Activity activity) {
if (!isNavigationBarShow(activity)) {
return 0;
}
Resources resources = activity.getResources();
int resourceId = resources.getIdentifier("navigation_bar_height",
"dimen", "android");
//获取NavigationBar的高度
int height = resources.getDimensionPixelSize(resourceId);
return height;
}
/**
* 精确的除法
*
* @param var1
* @param var2
* @param scale 保留的小数
* @return
*/
public static double div(double var1, double var2, int scale) {
if (scale < 0) {
throw new IllegalArgumentException("The scale must be a positive integer or zero");
}
BigDecimal b1 = new BigDecimal(Double.toString(var1));
BigDecimal b2 = new BigDecimal(Double.toString(var2));
return b1.divide(b2, scale, BigDecimal.ROUND_HALF_UP).doubleValue();
}
/**
* dp to px
*
* @param dpValue
* @return
*/
public static int dp2px(Context context, float dpValue) {
float scale = context.getResources().getDisplayMetrics().density;
return (int) (dpValue * scale + 0.5F);
}
}
四、使用
@Override
protected void onResume() {
super.onResume();
//开启监听截屏
if (screenShotManager != null) {
screenShotManager.startListener();
}
}
@Override
protected void onPause() {
super.onPause();
//关闭截屏监听(防止触发)
if (screenShotManager != null) {
screenShotManager.stopListener();
}
}
Github地址：https://github.com/lucklyperson/ShotScreenShareProject
如果问题，欢迎指教。
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