Question

我在Android应用程序上工作，我在屏幕上绘制一个红色圆圈。现在我想捕获布局参数＆＃34; wrap_content＆＃34;和＆＃34; fill_parent＆＃34;因为我想通过onMeasureCallback()函数更改每个参数布局类型的圆的大小。

如果我现在尝试，使用＆＃34; wrap_content＆＃34;高度和宽度始终相同和＆＃34; fill_parent＆＃34;。

activity_main

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
android:background="#FFFFFF"> 

    <com.example.myapplication.DrawingView
        android:id="@+id/drawing_circle_view"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
    <!--android:layout_width="wrap_content"  // this must be a different width than by using fill_parent-->
    <!--android:layout_height="wrap_content" // this must be a different height than by using fill_parent-->
    />

</LinearLayout>

DrawingView

public class DrawingView extends View {

    // setup initial color
    private final int paintColor = Color.RED;
    // defines paint and canvas
    private Paint drawPaint;
    private float size;

    public DrawingView(Context context, AttributeSet attrs) {
        super(context, attrs);

        // set standards
        setFocusable(true);
        setFocusableInTouchMode(true);

        // setting up paint
        setupPaint();

        // set on measure call back
        setOnMeasureCallback();
    }

    // Setup paint with color and stroke styles
    private void setupPaint() {
        drawPaint = new Paint();
        drawPaint.setColor(paintColor);
        drawPaint.setAntiAlias(true);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        canvas.drawCircle(size, size, size, drawPaint);
    }

    private void setOnMeasureCallback() {
        ViewTreeObserver viewTreeObserver = getViewTreeObserver();
        viewTreeObserver.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                removeOnGlobalLayoutListener(this);

                // how can I detect here which layout parameter I've used in the main_activity view?
            }
        });
    }

    @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
    private void removeOnGlobalLayoutListener(ViewTreeObserver.OnGlobalLayoutListener listener) {
        if (Build.VERSION.SDK_INT < 16) {
            getViewTreeObserver().removeGlobalOnLayoutListener(listener);
        } else {
            getViewTreeObserver().removeOnGlobalLayoutListener(listener);
        }
    }
}

Answer 1

尝试getLayoutParams().height，getLayoutParams().width。 MATCH_PARENT和WRAP_CONTENT

应该有固定的值

Answer 2

您可以通过对onMeasure中的数据进行逆向工程来实现此目的。但是View并没有直接传递这些信息。相反，他们通过了一个MeasureSpec，它将给出EXACT，AT_MOST或者不确定的大小和常量，并让视图设置自己的大小。看看你们每个人得到的价值。

Android：检测布局参数＆＃34; fill_parent＆＃34;和＆＃34; wrap_content＆＃34;

2 个答案: