使用FrameLayout作为根布局，在另一个视图的顶部添加具有X，Y偏移的视图 [英] With FrameLayout as root layout, add view on top of another one, with offset of X,Y

问题描述

我想将视图放置在现有视图之上.我定位的视图位于LinearLayout内部，该外观位于FrameLayout中.

I'd like to place a view on top of an existing view. The view I'm targeting is inside a LinearLayout, which resides in a FrameLayout.

我正在考虑使用RelativeLayout做到这一点，因为我已经使其部分工作了.我想将新视图对齐到左下角或左上角(作为原点)，然后将X和Y偏移到我指定的某个精确值.

I'm thinking there's a way to do this with RelativeLayout because I already have it partially working. I'd like to align the new view to the bottom-left or top-left (as the origin) and then offset X and Y to some precise value that I specify.

如何实现?

这里是个主意:

public static void placeTextRelativeToBottomLeftOfViewAtXY(final FrameLayout layout, View component, int x, int y, String text) {

    final TextView textView = new TextView(getContext());
    textView.setId((int)System.currentTimeMillis());
    final RelativeLayout relativeLayout = new RelativeLayout(getContext());
    RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT);
    params.setMargins(x, y, 0,0);
    params.addRule(RelativeLayout.LEFT_OF, component.getId());
    relativeLayout.setLayoutParams(params);
    relativeLayout.setBackgroundColor(Color.TRANSPARENT);
    textView.setText("+500 points!");
    textView.bringToFront();
    relativeLayout.addView(textView, params);
    layout.addView(relativeLayout);
}

推荐答案

基于注释中的其他信息，即使可以在FrameLayout中重叠不同的布局，这些布局也只能将其位置自己的孩子. RelativeLayout将无法将其子视图之一相对于其他同级或父布局中的视图放置.

Based on the additional information in comments, even if it is possible to overlap a different layouts inside a FrameLayout, those layouts will only be able to position their own children. A RelativeLayout won't be able to position one of its child views relative to a view in a different sibling or parent Layout.

可行的方法是平整布局的层次结构，将根布局设置为RelativeLayout或ConstraintLayout.

The way to go would be to flattern the heierarchy of Layouts, setting the root layout to a RelativeLayout or a ConstraintLayout.

ConstraintLayout在定位视图方面更灵活，但也更难以学习.

ConstraintLayout is more flexible in terms of positioning views, but it is also more difficult to learn.

在这里，我要留下一种替代方法，以供RelativeLayout用作根视图.要查看的重要项目是LayoutParams的设置，有时可能会引起混淆.
LayoutParams是在子视图上设置的，但是所使用的类取决于父视图.

Here I am leaving an alternative to be used with RelativeLayout as the root view. The important items to look at are the setting of the LayoutParams which is sometimes a bit confussing.
The LayoutParams are set on the child view, but the class used depends on the parent view.

还请记住，要保持页边空白独立显示，您需要将dp转换为像素(为简单起见，我没有这样做，但是在SO中有一些有关如何执行此操作的示例).

Also take in mind that to keep margins display independent you need to convert dp into pixels (for the sake of simplicity I haven't done that, but there are examples of how to do this here in SO).

它还使用View.generteViewId()来获取动态创建的视图的ID.

It also uses View.generteViewId() go get an id for a view created dynamically.

为简单起见，我在xml中包含了引用View，但是我也可以动态创建.

To make it simple I included the reference View in the xml, but i could have also been created dynamically.

布局

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/rlContainer"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/tvCenterText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Texto estatico"
        android:layout_centerInParent="true"/>

</RelativeLayout>

主要活动

public class DynamicViewsActivity extends AppCompatActivity {

    RelativeLayout rlContainer;
    TextView centerText;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_dynamicviews);

        rlContainer = findViewById(R.id.rlContainer);

        centerText = findViewById(R.id.tvCenterText);


        placeTextRelativeToBottomLeftOfViewAtXY(rlContainer, centerText, 100,10, "Hola");

    }

    public void placeTextRelativeToBottomLeftOfViewAtXY(final RelativeLayout layout, View component, int x, int y, String text) {

        final TextView textView = new TextView(this);
        textView.setId(View.generateViewId());
        RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
        params.setMargins(x, y, x,y);
        params.addRule(RelativeLayout.LEFT_OF, component.getId());
        params.addRule(RelativeLayout.ALIGN_BASELINE, component.getId());
        textView.setLayoutParams(params);
        textView.setText(text);
        layout.addView(textView);
    }
}

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