Android 为什么此ImageView不能与其父视图正确对齐？

我正在构建一个具有以下布局的应用程序：

RelativeLayout容器的背景是ImageView子级，页面的实际内容是另外两个RelativeLayout

这些视图的规则设置如下：

// Define rules and params for views in the container
ImageView backgroundImg = new ImageView(this);
RelativeLayout.LayoutParams lpImg = new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
lpImg.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
backgroundImg.setImageResource(R.drawable.baggrund_smartphones_retina);
backgroundImg.setLayoutParams(lpImg);

RelativeLayout mainLayout = (RelativeLayout)findViewById(R.id.fragment_main_layout);
RelativeLayout storeLayout = (RelativeLayout)findViewById(R.id.fragment_store_layout);
RelativeLayout.LayoutParams lp1 = new RelativeLayout.LayoutParams(screenWidth, LayoutParams.MATCH_PARENT);
RelativeLayout.LayoutParams lp2 = new RelativeLayout.LayoutParams(screenWidth, LayoutParams.MATCH_PARENT);
lp1.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
lp2.addRule(RelativeLayout.RIGHT_OF, R.id.fragment_main_layout);
mainLayout.setLayoutParams(lp1);
storeLayout.setLayoutParams(lp2);

root.removeAllViews();

//Add background first to ensure its in the back
snapView.addInfoPage(backgroundImg);
snapView.addInfoPage(mainLayout);

现在我的问题来了。但是我的RelativeLayouts与它们的父对象正确对齐，但是ImageView没有。相反，imageview是这样的位置：

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我做错了什么？

可能是您的图像尺寸小于父布局的屏幕尺寸

因此，如果您希望图像适合所有屏幕，请通过xml在imageView标记中使用attribute

android:scaleType

：

<ImageView android:id="@+id/img"
blabla 
blabla 
android:scaleType="fitXY" />

像这样改变

RelativeLayout.LayoutParams lpImg = new RelativeLayout.LayoutParams(screenWidth, LayoutParams.MATCH_PARENT);

代替

RelativeLayout.LayoutParams lpImg = new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);

然后像这样修复imageview

backgroundImg.setLayoutParams(ScaleType.FIT_XY);

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你在版面里放了些填充物吗？没有。从未添加任何填充。是否确定图像没有透明边缘：）？

backgroundImg.setLayoutParams(ScaleType.FIT_XY);