Android：如何以编程方式设置布局的大小

Question

作为 Android 应用程序的一部分，我正在构建一个按钮集。这些按钮是一组嵌套的 LinearLayouts 的一部分。使用权重，我可以根据包含的父 LinearLayout 的大小自动调整自己的大小。这个想法是，根据屏幕的像素数和密度，将包含布局的大小设置为多个像素；并让按钮集根据该更改自行调整大小。

接下来的问题是：如何调整布局大小。

我已经尝试了几种建议的技术，但没有一个可以接近工作。下面是构建按钮集的 XML 子集：

    <LinearLayout android:layout_height="104pt" android:id="@+id/numberPadLayout" android:orientation="horizontal" android:layout_width="104pt"
    android:background="#a0a0a0"
    android:layout_alignParentBottom="true" 
    android:layout_centerHorizontal="true"
>

    <LinearLayout android:layout_weight="2" android:layout_height="fill_parent" android:id="@+id/linearLayout1" android:orientation="vertical" android:layout_width="wrap_content">
        <Button android:text="1" android:id="@+id/button1" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="4" android:id="@+id/button4" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="7" android:id="@+id/button7" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="-" android:id="@+id/buttonDash" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
    </LinearLayout>
    <LinearLayout android:layout_weight="2" android:layout_height="fill_parent" android:id="@+id/linearLayout2" android:orientation="vertical" android:layout_width="wrap_content">
        <Button android:text="2" android:id="@+id/button2" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="5" android:id="@+id/button5" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="8" android:id="@+id/button8" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="0" android:id="@+id/button0" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
    </LinearLayout>

    <LinearLayout android:layout_weight="2" android:layout_height="fill_parent" android:id="@+id/linearLayout3" android:orientation="vertical" android:layout_width="wrap_content">
        <Button android:text="3" android:id="@+id/button3" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="6" android:id="@+id/button6" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="9" android:id="@+id/button9" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="." android:id="@+id/buttonDot" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
    </LinearLayout>
    <LinearLayout android:layout_weight="2" android:layout_height="fill_parent" android:id="@+id/linearLayout4" android:orientation="vertical" android:layout_width="wrap_content">
        <Button android:text="/" android:id="@+id/buttonBack" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
        <Button android:text="\" android:id="@+id/buttonEnter" android:layout_weight="2" android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>
    </LinearLayout>

</LinearLayout>    

这两个问题是：1）如何从 Java 访问 numberPadLayout。一旦我可以访问视图，2) 如何更改布局的高度和宽度。

任何建议将不胜感激。

Answer 1

Java

这应该可行：

// Gets linearlayout
LinearLayout layout = findViewById(R.id.numberPadLayout);
// Gets the layout params that will allow you to resize the layout
LayoutParams params = layout.getLayoutParams();
// Changes the height and width to the specified *pixels*
params.height = 100;
params.width = 100;
layout.setLayoutParams(params);

如果要将倾角转换为像素，请使用：

int height = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, <HEIGHT>, getResources().getDisplayMetrics());

Kotlin

Answer 2

LinearLayout YOUR_LinearLayout =(LinearLayout)findViewById(R.id.YOUR_LinearLayout)
    LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(
                       /*width*/ ViewGroup.LayoutParams.MATCH_PARENT,
               /*height*/ 100,
               /*weight*/ 1.0f
                );
                YOUR_LinearLayout.setLayoutParams(param);

Answer 3

我的示例代码

wv = (WebView) findViewById(R.id.mywebview);
wv.getLayoutParams().height = LayoutParams.MATCH_PARENT; // LayoutParams: android.view.ViewGroup.LayoutParams
// wv.getLayoutParams().height = LayoutParams.WRAP_CONTENT;
wv.requestLayout();//It is necesary to refresh the screen

Answer 4

您可以使用以下代码获取被调用布局的实际高度：

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();
}