Java 布局参数是否需要API 19？

我正在使用Andengine并希望添加Admob横幅。我找到了这个代码，它工作得很好。但是对于这段代码，LayoutParams至少需要API 19。我想要低一点，比如说8点之类的。我可以用什么来代替

@Override protected void onSetContentView() {
    // CREATING the parent FrameLayout //
    final FrameLayout frameLayout = new FrameLayout(this);

    // CREATING the layout parameters, fill the screen //
    final FrameLayout.LayoutParams frameLayoutLayoutParams =
            new FrameLayout.LayoutParams(FrameLayout.LayoutParams.MATCH_PARENT,
                                         FrameLayout.LayoutParams.MATCH_PARENT);

    // CREATING a Smart Banner View //
    adView = new AdView(this);
    adView.setAdSize(AdSize.SMART_BANNER);
    adView.setAdUnitId("ca-app-pub-2181015300018417/9550656088");

    // Doing something I'm not 100% sure on, but guessing by the name //
    adView.refreshDrawableState();
    adView.setVisibility(AdView.VISIBLE);

    // ADVIEW layout, show at the bottom of the screen //
    final FrameLayout.LayoutParams adViewLayoutParams =
            new FrameLayout.LayoutParams(FrameLayout.LayoutParams.WRAP_CONTENT,
                                         FrameLayout.LayoutParams.WRAP_CONTENT,
                                         Gravity.CENTER_HORIZONTAL|Gravity.BOTTOM);

    // REQUEST an ad (Test ad) //
    AdRequest adRequest = new AdRequest.Builder()
    .addTestDevice(AdRequest.DEVICE_ID_EMULATOR)
    .addTestDevice("AB38B36BA72798C94A9C9329007FD4B0")
    .build();
    adView.loadAd(adRequest);

    // RENDER the add on top of the scene //
    this.mRenderSurfaceView = new RenderSurfaceView(this);
    mRenderSurfaceView.setRenderer(mEngine, this);

    // SURFACE layout ? //
    final android.widget.FrameLayout.LayoutParams surfaceViewLayoutParams =
            new FrameLayout.LayoutParams(super.createSurfaceViewLayoutParams());

    // ADD the surface view and adView to the frame //
    frameLayout.addView(this.mRenderSurfaceView, surfaceViewLayoutParams);
    frameLayout.addView(adView, adViewLayoutParams);

    // SHOW AD //
    this.setContentView(frameLayout, frameLayoutLayoutParams);

---

}//onSetContentView（）的结尾//

问题在于FrameLayout.LayoutParams构造函数 不支持 另一个FrameLayout作为参数，直到api 19

但是，还有两个签名：

public FrameLayout.LayoutParams（ViewGroup.LayoutParams源）-api 1

public FrameLayout.LayoutParams（ViewGroup.MarginLayoutParams源）-api 1

FrameLayout.LayoutParams是ViewGroup.MarginLayoutParams子类

因此，在检查参数layout是否为FrameLayout.LayoutParams之后

您可以按以下方式解决此问题：

        if(super.createSurfaceViewLayoutParams() instanceOf FrameLayout.LayoutParams){

         final android.widget.FrameLayout.LayoutParams surfaceViewLayoutParams =
                    new FrameLayout.LayoutParams((ViewGroup.MarginLayoutParams)super.createSurfaceViewLayoutParams());
    }

第一个签名之间的差异（API 19） 及其他 新的LayoutParams对象将不会设置重力

 if(super.createSurfaceViewLayoutParams() instanceOf FrameLayout.LayoutParams){


    ViewGroup.MarginLayoutParams paramLP=(ViewGroup.MarginLayoutParams)super.createSurfaceViewLayoutParams();

    int gravityHolder=((FrameLayout.LayoutParams)super.createSurfaceViewLayoutParams()).gravity;


             final android.widget.FrameLayout.LayoutParams surfaceViewLayoutParams =
                        new FrameLayout.LayoutParams(paramLP);

    surfaceViewLayoutParams.gravity=gravityHolder;
        }

我的工作方法如下：

final android.widget.FrameLayout.LayoutParams surfaceViewLayoutParams =
android.widget.FrameLayout.LayoutParams(android.view.ViewGroup.LayoutParams.MATCH_PARENT,android.view.ViewGroup.LayoutParams.MATCH_PARENT);
surfaceViewLayoutParams.gravity = Gravity.CENTER;

---

似乎适用于Android Studio+Andengine，不需要API19。

阅读文档。只有一个构造函数是api19，其余的都是API1。您可能并不真正需要该构造函数。根据文档，它不需要api 19。只有一个构造函数需要api 19，只需使用另一个。我使用了另一个，现在它工作得很好。谢谢大家！

final android.widget.FrameLayout.LayoutParams surfaceViewLayoutParams =
android.widget.FrameLayout.LayoutParams(android.view.ViewGroup.LayoutParams.MATCH_PARENT,android.view.ViewGroup.LayoutParams.MATCH_PARENT);
surfaceViewLayoutParams.gravity = Gravity.CENTER;