獲取 HorizontalScrollView 子項的寬度

Question

我正在嘗試獲取 HorizontalScrollView 子項的寬度，但是我的寬度始終與我的 HorizontalScrollView 相同

我嘗試覆蓋 onMeasure 和 onLayout 並調用 measure() 但我得到 0、100 或與我的 HorizontalScrollView 相同的寬度

我目前的代碼是

void adjustClip(int r, int b) {
    // ommited
}

void getWindowSize() {
    if (mOrientation == VERTICAL) {
        windowHeight = document.getHeight();
    } else {
        windowWidth = document.getWidth();
    }
}

boolean getDocumentSizeTypeRecyclerView() {
    // ommited
}

void printWidths(View view) {
    Log.d(TAG, "view.getRight() = [" + (view.getRight()) + "]");
    Log.d(TAG, "view.getWidth() = [" + (view.getWidth()) + "]");
    Log.d(TAG, "view.getMeasuredWidth() = [" + (view.getMeasuredWidth()) + "]");
    Log.d(TAG, "view.getMeasuredWidthAndState() = [" + (view.getMeasuredWidthAndState()) + "]");
    Log.d(TAG, "view.getMinimumWidth() = [" + (view.getMinimumWidth()) + "]");
    Log.d(TAG, "view.getVerticalScrollbarWidth() = [" + (view.getVerticalScrollbarWidth()) + "]");
}

boolean getDocumentSizeTypeHorizontalScrollView() {
    if (document instanceof HorizontalScrollView) {
        HorizontalScrollView horizontalScrollView = (HorizontalScrollView) document;
        printWidths(horizontalScrollView);
        printWidths(horizontalScrollView.getChildAt(0));
        View child = ((ViewGroup) document).getChildAt(0);
        documentWidth = child.getWidth();
        return true;
    } else return false;
}

boolean getDocumentSize() {
    if (getDocumentSizeTypeRecyclerView()) return true;
    if (getDocumentSizeTypeHorizontalScrollView()) return true;
    return false;
}

void setThumbSize(int b, int r) {
    if (mOrientation == VERTICAL) {
        documentHeightDivWindowHeight = documentHeight / windowHeight;
        float thumbHeight = b / documentHeightDivWindowHeight;
        clip.setHeight((int) thumbHeight);
    } else {
        documentWidthDivWindowWidth = documentWidth / windowWidth;
        float thumbWidth = r / documentWidthDivWindowWidth;
        clip.setWidth((int) thumbWidth);
    }
}

void doScroll(int r, int b) {
    if (document != null) {
        getWindowSize();
        if (getDocumentSize()) {
            setThumbSize(b, r);
            if (!scrolling) scrollDocument();
        }
    }
}

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
    super.onLayout(changed, l, t, r, b);
    if (DEBUG) Log.d(TAG, "onLayout() called with: changed = [" + changed + "], l = [" + l + "], t = [" + t + "], r = [" + r + "], b = [" + b + "]");
    if (layout) {
        layout = false;
    } else {
        layout = true;
        adjustClip(r, b);
        doScroll(r, b);
    }
}

這就是它打印的內容

D/ScrollBarView: onLayout() called with: changed = [false], l = [80], t = [0], r = [760], b = [80]
// HorizontalScrollView
    view.getRight() = [1140]
    view.getWidth() = [840]
    view.getMeasuredWidth() = [840]
    view.getMeasuredWidthAndState() = [840]
    view.getMinimumWidth() = [0]
    view.getVerticalScrollbarWidth() = [14]
// child
    view.getRight() = [840]
    view.getWidth() = [840]
    view.getMeasuredWidth() = [840]
    view.getMeasuredWidthAndState() = [840]
    view.getMinimumWidth() = [0]
    view.getVerticalScrollbarWidth() = [0]

因為我正在嘗試為 android 制作外部滾動條視圖，因為我無法修改 ScrollView 和相關的內部滾動條

這就是我的視圖，突出顯示滾動視圖子視圖

Answer 1

如果我理解正確，您在計算並放置在屏幕上之前測量的視圖大小。

我認為您可以添加一個偵聽器，該偵聽器將在計算完布局后運行

view.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
@Override
   public void onGlobalLayout() {
      view.getViewTreeObserver().removeOnGlobalLayoutListener(this);
      printWidths(view);
   }
});

波紋管如何在代碼中使用它：

主要活動：

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final ExternalScrollBar esb = (ExternalScrollBar) findViewById(R.id.esb);

        esb.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                esb.getViewTreeObserver().removeOnGlobalLayoutListener(this);
                LinearLayout ll = (LinearLayout) esb.getChildAt(0);
                TextView tv = (TextView) ll.getChildAt(0);
                TextView tv2 = (TextView) ll.getChildAt(1);
                printWidths(esb);
                printWidths(tv);
                printWidths(tv2);
            }
        });
    }

    void printWidths(View view) {
        System.out.println("view.getRight() = [" + (view.getRight()) + "]");
        System.out.println("view.getWidth() = [" + (view.getWidth()) + "]");
        System.out.println("view.getMeasuredWidth() = [" + (view.getMeasuredWidth()) + "]");
        System.out.println("view.getMeasuredWidthAndState() = [" + (view.getMeasuredWidthAndState()) + "]");
        System.out.println("view.getMinimumWidth() = [" + (view.getMinimumWidth()) + "]");
        System.out.println("view.getVerticalScrollbarWidth() = [" + (view.getVerticalScrollbarWidth()) + "]");
    }
}

外部滾動條

public class ExternalScrollBar extends HorizontalScrollView {
    public ExternalScrollBar(Context context) {
        super(context);
    }
    public ExternalScrollBar(Context context, AttributeSet attributeSet) {
        super(context, attributeSet);
    }


    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        super.onLayout(changed, l, t, r, b);
        System.out.println(this.getWidth());
        System.out.println(((LinearLayout)this.getChildAt(0)).getChildAt(0).getWidth());
        System.out.println(((LinearLayout)this.getChildAt(0)).getChildAt(1).getWidth());
    }
}

活動布局

<?xml version="1.0" encoding="utf-8"?>
<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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <com.example.stackhorizontalchild.ExternalScrollBar
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/esb"
        >

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Hello World 5212! "
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Hello Wor!"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
        </LinearLayout>
    </com.example.stackhorizontalchild.ExternalScrollBar>

</LinearLayout>

運行結果：

I/System.out: 472 //onLayout
I/System.out: 302
I/System.out: 170
view.getRight() = [472] //ExternalScrollBar
view.getWidth() = [472]
view.getMeasuredWidth() = [472]
view.getMeasuredWidthAndState() = [472]
view.getMinimumWidth() = [0]
view.getVerticalScrollbarWidth() = [11]
view.getRight() = [302] //Child TextView1
view.getWidth() = [302]
view.getMeasuredWidth() = [302]
view.getMeasuredWidthAndState() = [302]
view.getMinimumWidth() = [0]
view.getVerticalScrollbarWidth() = [0]
view.getRight() = [472] //Child TextView2
view.getWidth() = [170]
view.getMeasuredWidth() = [170]
view.getMeasuredWidthAndState() = [170]
view.getMinimumWidth() = [0]
view.getVerticalScrollbarWidth() = [0]

Answer 2

這好像是

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);

        View child = horizontalScrollView.getChildAt(0);
        if (child == null) {
            width = child.getWidth();
        }
    }
}

是獲取水平滾動視圖寬度的正確方法