FrameLayout 中动态创建的 TextView 没有宽度

Dynamically created TextView in FrameLayout has no width

我正在尝试将代码中的 TextView 添加到框架布局。它位于框架布局的 z 顺序中的图像视图上方。最终目标是允许从显示图像和已覆盖在其上的文本的框架布局创建屏幕截图。当我使用在 xml 中创建的文本视图但在动态代码版本中没有时,我有这个工作。创建位图方法 returns 抱怨文本框的宽度为 0 的错误。在下面的代码中,我试图仅将文本视图捕获为图像以确定问题所在,因为从框架布局捕获的图像没有按预期包含文本视图的内容。在这样做的过程中,我能够找到宽度错误,我相信这就是问题的根源。我尝试使用 setWidth 和 LayoutParams 设置文本视图的宽度。尽管在手机上可以清楚地看到,但最终结果始终是 textview 没有宽度。我想我在动态创建和现有的 xml 之间遗漏了一些东西,这导致了 0 宽度。谁能给我指出正确的方向?

代码如下

   public void applyTextToImage(View view) {
    // Do something in response to button

    //Hide the virtual keyboard


    InputMethodManager inputManager = (InputMethodManager) getSystemService(this.INPUT_METHOD_SERVICE);
    inputManager.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);

    //Get the text to overlay on the image
    EditText editText = (EditText) findViewById(R.id.edit_message);
    String message = editText.getText().toString();

    //Bring the overlay layout to the front
   //LinearLayout overlay_layout = (LinearLayout) findViewById(R.id.image_Overlay_Layout);
   //overlay_layout.bringToFront();

    //Apply the new text to the text box

    /* Old code to get the view that is shown in the layout
    TextView text_overlay = (TextView) findViewById(R.id.image_Overlay);
    text_overlay.bringToFront();
    text_overlay.setText(message);
    */

    //New code to create a view dynamically instead

    TextView text_Overlay = new TextView(this);
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1) {
        text_Overlay.setId(Utils.generateViewId());
    }
    else
    {
        text_Overlay.setId(TextView.generateViewId()); //static class
    }
    FrameLayout image_Layout =  (FrameLayout) findViewById(R.id.image_Layout);
    //View image_Layout =  (View) findViewById(R.id.image_Layout);
    //FrameLayout.LayoutParams fParams = new FrameLayout.LayoutParams(FrameLayout.LayoutParams.MATCH_PARENT,FrameLayout.LayoutParams.WRAP_CONTENT);
    FrameLayout.LayoutParams fParams = new FrameLayout.LayoutParams(FrameLayout.LayoutParams.MATCH_PARENT,FrameLayout.LayoutParams.WRAP_CONTENT);
    fParams.gravity = Gravity.CENTER;

   // text_Overlay.setMaxWidth(image_Layout.getWidth());
   // text_Overlay.setWidth(image_Layout.getWidth());
    //image_Layout.addView(text_Overlay, fParams);
    image_Layout.addView(text_Overlay, fParams);
    Toast.makeText(this,"TextView Width: " + text_Overlay.getWidth(),Toast.LENGTH_LONG).show();

    //TODO: Something has forced the dynamic layout to not be saved in  the bitmap try removing the params and set the values on the textview itself
    //TODO: for some reason the width keeps coming back as 0 could be that the image_Layout is 0 too

    text_Overlay.setGravity(Gravity.CENTER);
    text_Overlay.setTextAlignment(View.TEXT_ALIGNMENT_CENTER);
    float pixels = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 10, getResources().getDisplayMetrics());
    //text_Overlay.setWidth(250dp);

    text_Overlay.setTextSize(pixels);
    text_Overlay.setTextColor(Color.RED);
    text_Overlay.bringToFront();
    text_Overlay.setText(message);
    text_Overlay.setVisibility(View.VISIBLE);
    //End of new dynamic code

    if (folderCheck()){
        try {
            String filePath = getFilePath();
            int myId = text_Overlay.getId();

            Bitmap bitmap;
            View v1 = findViewById(myId);

            v1.setDrawingCacheEnabled(true);

            v1.buildDrawingCache();

            bitmap = Bitmap.createBitmap(v1.getDrawingCache());
            v1.setDrawingCacheEnabled(false);
            // End imported code

            streamBitmapToFile(bitmap, filePath);
        }
        catch (Exception e)
        {
            Toast.makeText(this,e.getMessage(),Toast.LENGTH_LONG);
            Log.e("Bitmap Creation","Couldn't create bitmap error as: "  + e.toString());
        }
    }
}

XML 内容

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin">

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="false">
    <!--app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:showIn="@layout/activity_my"-->

    <EditText android:id="@+id/edit_message"
        android:layout_weight="1"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:hint="@string/edit_message"
        android:enabled="false"/>

    <Button android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/button_send"
        android:onClick="applyTextToImage"
        android:enabled="false"
        android:id="@+id/overlayButton"/>

</LinearLayout>

<FrameLayout
    android:id="@+id/image_Layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true">

    <ImageView
        android:id="@+id/image_View"
        android:layout_width="match_parent"
        android:layout_height="250dp" />

   <!--<TextView
        android:id="@+id/image_Overlay"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:textAlignment="center"
        android:textSize="25dp"
        android:textColor="#ff0000"/>-->

</FrameLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="false"
android:gravity="bottom"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true">

<Button android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/open_gallery"
    android:onClick="openGallery">
</Button>

<Button android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/new_image"
    android:onClick="newImage">
</Button>

</LinearLayout>
</RelativeLayout>

视图尚未测量。在系统执行另一次布局传递之前,视图将其宽度报告为零。

在我看来,您最好将 TextView 保留在 XML 布局中并简单地使其不可见 (android:visibility="invisible") 直到您需要它,然后使用 [=11 使其可见=]. (注意,如果设置为gone,同样不会被测量。)

作为参考,Karakuri 指出了弱点和解决这些问题的途径。

为侦听器实现的额外代码如下。

IMAGE_CAPTURE_REQUESTED = true;

    // New Listener
    ViewTreeObserver vto = image_Layout.getViewTreeObserver();
    vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {


            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
                image_Layout.getViewTreeObserver().removeGlobalOnLayoutListener(this);
            }
            else
            {
                image_Layout.getViewTreeObserver().removeOnGlobalLayoutListener(this);
            }

            if (IMAGE_CAPTURE_REQUESTED) {
                //int myId = text_Overlay.getId();
                //Toast.makeText(MyActivity.this, "Text Overlay Width " + text_Overlay.getWidth() ,Toast.LENGTH_LONG).show();
                overlayTextAndExportImage();
            }
        }
    }); //End New Listener

新的 overlayTextAndImportImage 在重绘布局后调用所有图像创建例程。