Android 如何将自定义视图添加到布局中，以便与父视图匹配？

我有以下自定义视图（基本上是一个包含图像的视图，您可以在该图像上绘制矩形）

我试过：

<LinearLayout 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:orientation="horizontal" >

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"
    android:weightSum="1" >

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="0.8"
        android:orientation="vertical"
        android:weightSum="1" >

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="0.9" >

            <HorizontalScrollView
                android:id="@+id/horizontal"
                android:layout_width="match_parent"
                android:layout_height="match_parent" >

                <ScrollView
                    android:id="@+id/vertical"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent" >

                    <com.example.test.MyView
                        android:id="@+id/image"
                        android:layout_width="match_parent"
                        android:layout_height="match_parent" />
                      </ScrollView>
            </HorizontalScrollView>
        </LinearLayout>

但是没有成功

可绘制的图像不显示

---

它显示一个空白字段…

您应该在自定义视图中覆盖

onMeasure（）

@Override
public void onMeasure(int widthSpecs, int heightSpecs) {
    super.onMeasure(widthSpecs, heightSpecs);
    setMeasuredDimension(mDisplayUtils.getScreenWidth(), mDisplayUtils.getScreenHeight());
}

或者任何你想要的价值观

我能想到的另一件事是，在主构造函数上初始化变量。这样做：

public MyView(Context c) {
    super(c);
    init();
}

public MyView(Context context, AttributeSet attrs) {
    super(context, attrs);
    init();
}

public MyView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    init();
}

private void init(){
    Log.e("","call first constructor");
    mPath = new Rect();
    mBitmapPaint = new Paint(Paint.DITHER_FLAG);
    mPaint = new Paint();
    mPaint.setAntiAlias(true);
    mPaint.setDither(true);
    mPaint.setColor(0xFFFF0000);
    mPaint.setStyle(Paint.Style.STROKE);
    mPaint.setStrokeJoin(Paint.Join.ROUND);
    mPaint.setStrokeCap(Paint.Cap.ROUND);
    mPaint.setStrokeWidth(3);
}

---

感谢Android开发者也许我明白了你的观点，但是我应该在测量中加入什么来允许匹配父项呢？…尝试了

@覆盖测量上的公共空白（int-widthSpecs，int-heightSpecs）{setMeasuredDimension（MeasureSpec.getSize（widthSpecs），MeasureSpec.getSize（heightSpecs））；}

但是没有成功

@Override
public void onMeasure(int widthSpecs, int heightSpecs) {
    super.onMeasure(widthSpecs, heightSpecs);
    setMeasuredDimension(mDisplayUtils.getScreenWidth(), mDisplayUtils.getScreenHeight());
}

public MyView(Context c) {
    super(c);
    init();
}

public MyView(Context context, AttributeSet attrs) {
    super(context, attrs);
    init();
}

public MyView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    init();
}

private void init(){
    Log.e("","call first constructor");
    mPath = new Rect();
    mBitmapPaint = new Paint(Paint.DITHER_FLAG);
    mPaint = new Paint();
    mPaint.setAntiAlias(true);
    mPaint.setDither(true);
    mPaint.setColor(0xFFFF0000);
    mPaint.setStyle(Paint.Style.STROKE);
    mPaint.setStrokeJoin(Paint.Join.ROUND);
    mPaint.setStrokeCap(Paint.Cap.ROUND);
    mPaint.setStrokeWidth(3);
}