android14截屏

systemui的做法

frameworks/base/packages/SystemUI/src/com/android/systemui/screenshot/ImageCaptureImpl.kt

package com.android.systemui.screenshot

import android.app.IActivityTaskManager
import android.graphics.Bitmap
import android.graphics.Rect
import android.view.IWindowManager
import android.window.ScreenCapture
import android.window.ScreenCapture.CaptureArgs
import com.android.systemui.dagger.SysUISingleton
import com.android.systemui.dagger.qualifiers.Background
import javax.inject.Inject
import kotlinx.coroutines.CoroutineDispatcher
import kotlinx.coroutines.withContext

private const val TAG = "ImageCaptureImpl"

@SysUISingleton
open class ImageCaptureImpl @Inject constructor(
    private val windowManager: IWindowManager,
    private val atmService: IActivityTaskManager,
    @Background private val bgContext: CoroutineDispatcher
) : ImageCapture {

    override fun captureDisplay(displayId: Int, crop: Rect?): Bitmap? {
        val captureArgs = CaptureArgs.Builder()
            .setSourceCrop(crop)
            .build()
        val syncScreenCapture = ScreenCapture.createSyncCaptureListener()
        windowManager.captureDisplay(displayId, captureArgs, syncScreenCapture)
        val buffer = syncScreenCapture.getBuffer()
        return buffer?.asBitmap()
    }

    override suspend fun captureTask(taskId: Int): Bitmap? {
        val snapshot = withContext(bgContext) {
            atmService.takeTaskSnapshot(taskId, false /* updateCache */)
        } ?: return null
        return Bitmap.wrapHardwareBuffer(snapshot.hardwareBuffer, snapshot.colorSpace)
    }
}

displayId 是 framework 逻辑 ID（0、1、2…）。
不需要 root，但调用者必须是 system/privileged 进程，且持有 CAPTURE_DISPLAY 权限。

命令行写法

screencap -p /data/data/aaa.png

MediaProjection写法

网上demo多，不赘述