如何从非父文件 [Android] 访问文本视图

Question

我想从非父文件访问和更改文本视图的文本。

这是我想从中进行编辑的类

class BarcodeProcessor(graphicOverlay: GraphicOverlay, private val workflowModel: WorkflowModel) :
    FrameProcessorBase<List<FirebaseVisionBarcode>>() {

在这个类中，没有onCreat((

我是否需要具有 AppCompatActivity(( 才能访问 xml 布局文件？

在此文件中是处理条形码的位置，我可以向控制台显示结果以及SQL查询，但我想更新界面以反映这些值。我可以通过伴随对象将它们传递给父类吗？

有什么方法可以从条形码处理器文件进行布局更新吗？

我试过包括导入

import kotlinx.android.synthetic.main.barcode_field.*

    @MainThread
    override fun onSuccess(
        image: FirebaseVisionImage,
        results: List<FirebaseVisionBarcode>,
        graphicOverlay: GraphicOverlay
    ) {
        var z = ""
        var isSuccess: Boolean? = false
        //Variables used in the SQL query
        var strData = ""
        var strData2 = ""
        try {
            con = dbConn()      // Connect to database
            if (con == null) {
                z = "Check Your Internet Access!"
            } else {
                val query = "select [ValueOne], [ValueTwo] from [TableName] where [ValueOne] = '$barcodeValue'"
                val stmt = con!!.createStatement()
                val cursor = stmt.executeQuery(query)
                barcodeValue = results[0].getRawValue()!!
                println(barcodeValue)
                if (cursor.next()) {
                    //Selects the values from the columns in the table where the query is taking place
                    strData = cursor.getString("[ValueOne]")
                    strData2 = cursor.getString("[ValueTwo]")
                    var finalDispositionID = strData
                    var moduleSizeID = strData2
                    println(finalDispositionID)
                    println(moduleSizeID)
                    //barcode_field_value3 is the name of the textview
                    //barcode_field_value2 is the name of the other textview
                    //barcode_field_value3.text = strData
                    z = "Login successful"
                    isSuccess = true
                    con!!.close()
                } else {
                    z = "Invalid Credentials!"
                    isSuccess = false
                }
            }
        } catch (ex: java.lang.Exception) {
            isSuccess = false
            z = ex.message!!
        }

查询发生在函数 onSuccess(( 中。不过，我包含了整个文件以供参考。

实时条形码扫描活动

    private fun setUpWorkflowModel() {
        workflowModel = ViewModelProviders.of(this).get(WorkflowModel::class.java)
        // Observes the workflow state changes, if happens, update the overlay view indicators and
        // camera preview state.
        workflowModel!!.workflowState.observe(this, Observer { workflowState ->
            if (workflowState == null || Objects.equal(currentWorkflowState, workflowState)) {
                return@Observer
            }
            currentWorkflowState = workflowState
            Log.d(TAG, "Current workflow state: ${currentWorkflowState!!.name}")
            val wasPromptChipGone = promptChip?.visibility == View.GONE
            when (workflowState) {
                WorkflowState.DETECTING -> {
                    promptChip?.visibility = View.VISIBLE
                    promptChip?.setText(R.string.prompt_point_at_a_barcode)
                    startCameraPreview()
                }
                WorkflowState.CONFIRMING -> {
                    promptChip?.visibility = View.VISIBLE
                    promptChip?.setText(R.string.prompt_move_camera_closer)
                    startCameraPreview()
                }
                WorkflowState.SEARCHING -> {
                    promptChip?.visibility = View.VISIBLE
                    promptChip?.setText(R.string.prompt_searching)
                    stopCameraPreview()
                }
                WorkflowState.DETECTED, WorkflowState.SEARCHED -> {
                    promptChip?.visibility = View.GONE
                    stopCameraPreview()
                }
                else -> promptChip?.visibility = View.GONE
            }
            val shouldPlayPromptChipEnteringAnimation = wasPromptChipGone && promptChip?.visibility == View.VISIBLE
            promptChipAnimator?.let {
                if (shouldPlayPromptChipEnteringAnimation && !it.isRunning) it.start()
            }
        })

        workflowModel?.detectedBarcode?.observe(this, Observer { barcode ->
            if (barcode != null) {
                val barcodeFieldList = ArrayList<BarcodeField>()
                barcodeFieldList.add(BarcodeField("Module Serial Number", barcode.rawValue ?: ""))
                BarcodeResultFragment.show(supportFragmentManager, barcodeFieldList)
            }
        })
    }```

Answer 1

您正在BarcodeProcessor中设置workflowModel.detectedBarcode实时数据。因此，您可以找到将此workflowModel传递给构造函数的位置BarcodeProcessor并添加这样的代码以在活动中观察此实时数据：

workflowModel.detectedBarcode.observe(this, Observer { 
    myTextView.text = it
})

Answer 2

此答案直接涉及在 Google ML-Kit Showcase 示例项目中显示结果。因此，如果您使用条形码扫描进行研究，这是相关的。

为了在成功扫描时显示结果，您需要将字段添加到

条形码字段适配器文件

    internal class BarcodeFieldViewHolder private constructor(view: View) : RecyclerView.ViewHolder(view) {
        private val labelView: TextView = view.findViewById(R.id.barcode_field_label)
        private val valueView: TextView = view.findViewById(R.id.barcode_field_value)
        private val moduleSize: TextView = view.findViewById(R.id.textViewModuleSize)
        private val finalDisposition: TextView = view.findViewById(R.id.textViewFinalDisp)
        private val NCRNotes: TextView = view.findViewById(R.id.textViewNCR)
        private val OverlapLengthText: TextView = view.findViewById((R.id.textViewOverlapLength))
        fun bindBarcodeField(barcodeField: BarcodeField) {
            //These are the original values that display in the Barcode_field.xml
            labelView.text = barcodeField.label
            valueView.text = barcodeField.value
            //These are the new values I passed in
            moduleSize.text = BarcodeProcessor.data.moduleSize
            finalDisposition.text = BarcodeProcessor.data.finalDisposition
            NCRNotes.text = BarcodeProcessor.data.NCRNotes
            OverlapLengthText.text = BarcodeProcessor.data.OverlapLength
        }

里面

条码处理器

声明数据对象

    object data {
        var finalDisposition = "init"
        var moduleSize = "init"
        var barcodeValue: String = ""
        var NCRNotes = ""
        var OverlapLength = ""
    }

这些变量将被传递到上面的 BarcodeFieldAdapter 文件中，然后在成功时显示在barcode_field.xml中。

在查询函数内 - 即在条形码处理器文件中

//Selects the values from the columns in the table where the query is taking place
                    strData = cursor.getString("Column Name 1")
                    strData2 = cursor.getString("Column Name 2")
                    strData4 = cursor.getString("Column Name 3")
                    //Assigns the values to the variables inside the object data
                    data.finalDisposition = strData
                    data.moduleSize = strData2
                    data.OverlapLength = strData4
                    data.NCRNotes = ""

最后，在barcode_field.xml文件中，使用 (R.id.TextViewNAMES( 创建 TextViews，如上面的 BarcodeFieldAdapter 文件所示。现在，成功扫描后，将显示查询中的新值。