Android：如何根据尺寸创建自定义布局

Question

I need an advice...I want to create custom view group that will have different layout depending on size of this view.

An example:

Two views:

• View A: child view that is at least 50dp height
• View B: my custom view that extends vertically oriented LinearLayout and is 200 dp height

What I want:

1. When I insert 2 Views A into View B:
   • I want to stretch these two Views A to 100 dp. So B will be common linear layout with 2 children.
2. When I insert 5 Views A into View B:
   • I want to add scroll view into B. All 5 Views A will be inside this scroll view and they will be 50 dp height.

Usually, I add views to my custom view in constructor. But I can't do it here because I don't know height of B in constructor. I know only height of A. So please advice me which callback method should I use...when height of B will be known so I can add all child views according this height.

Or if you know any other approach...please let me know...

Thank you very much!

Answer 1

you should consider to put all views into a vertical linear layout which is in a scrollview , or better yet: use a single listView instead of layouts and scrollViews .

The reason is that it will handle the scrolling automatically if needed, depending on the available space on the screen and the size of your views.

Answer 2

You can use this code the get the actual height of main layout. Then you can use that height in a if-else or switch-case block to check the needed conditions.

public int getLayoutSize() {
// Get the layout id
    final LinearLayout root = (LinearLayout) findViewById(R.id.mainroot);
    final AtomicInteger layoutHeight = new AtomicInteger();

    root.post(new Runnable() { 
    public void run() { 
        Rect rect = new Rect(); 
        Window win = getWindow();  // Get the Window
                win.getDecorView().getWindowVisibleDisplayFrame(rect);

                // Get the height of Status Bar
                int statusBarHeight = rect.top;

                // Get the height occupied by the decoration contents 
                int contentViewTop = win.findViewById(Window.ID_ANDROID_CONTENT).getTop();

                // Calculate titleBarHeight by deducting statusBarHeight from contentViewTop  
                int titleBarHeight = contentViewTop - statusBarHeight; 
                Log.i("MY", "titleHeight = " + titleBarHeight + " statusHeight = " + statusBarHeight + " contentViewTop = " + contentViewTop); 

                // By now we got the height of titleBar & statusBar
                // Now lets get the screen size
                DisplayMetrics metrics = new DisplayMetrics();
                getWindowManager().getDefaultDisplay().getMetrics(metrics);   
                int screenHeight = metrics.heightPixels;
                int screenWidth = metrics.widthPixels;
                Log.i("MY", "Actual Screen Height = " + screenHeight + " Width = " + screenWidth);   

                // Now calculate the height that our layout can be set
                // If you know that your application doesn't have statusBar added, then don't add here also. Same applies to application bar also 
                layoutHeight.set(screenHeight - (titleBarHeight + statusBarHeight));
                Log.i("MY", "Layout Height = " + layoutHeight);   

            // Lastly, set the height of the layout       
            FrameLayout.LayoutParams rootParams = (FrameLayout.LayoutParams)root.getLayoutParams();
            rootParams.height = layoutHeight.get();
            root.setLayoutParams(rootParams);
        }
    });

return layoutHeight.get();
}