android：將視圖添加到虛擬視圖

Question

我想從我的res/layout目錄中膨脹佈局，並在我的活動類中添加一些視圖。

我的佈局xml文件：

<?xml version="1.0" encoding="utf-8"?> 

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_marginTop="30dip" 
    android:layout_height="fill_parent" > 

    <Button 
     android:id="@+id/reg_button" 
     style="@style/simple_button" 
     android:onClick="clickButton" 
     android:text="@string/reg_button" /> 


    <!-- I WANT TO PUT CONTENT HERE ! --> 

</LinearLayout> 

在我的Java代碼中，我試圖誇大上述佈局和添加的LinearLayout一個按鈕。

@Override 
public void onCreate(Bundle savedInstanceState) { 

    super.onCreate(savedInstanceState); 
    mContext = getApplicationContext(); 

    //inflate xml 
    LinearLayout mainLayout = (LinearLayout)  LayoutInflater.from(getBaseContext()).inflate(R.layout.regions_search, null); 


    //Create a new LinearLayout 
    LinearLayout newLinear = new LinearLayout(mContext);   
    newLinear.setLayoutParams(new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT)); 

    //create a new Button 
    Button test = new Button(mContext); 
    test.setText("My button"); 

    //first , I add button to the LinearLayout 
    newLinear.addView(test); 

    //Then, I add layout to the inflated layout 
    mainLayout.addView(newLinear); 


    //display 
    setContentView(mainLayout); 

但是newLinear視圖（及其子項）沒有顯示出來。

Answer 1

使用此在您的活動，

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 

    // display 
    setContentView(R.layout.activity_main); 

    Context mContext = getApplicationContext(); 
    LinearLayout mainLayout = (LinearLayout) findViewById(R.id.regions_search); 
    // Create a new LinearLayout 
    LinearLayout newLinear = new LinearLayout(mContext); 
    newLinear.setLayoutParams(new LinearLayout.LayoutParams(
      LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT)); 

    // create a new Button 
    Button test = new Button(mContext); 
    test.setText("My button"); 

    // first , I add button to the LinearLayout 
    newLinear.addView(test); 

    // Then, I add layout to the inflated layout 
    mainLayout.addView(newLinear); 
} 

，並在寫你的XML文件（activity_main.xml中），如下圖所示，

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:id="@+id/regions_search" 
android:layout_width="fill_parent" 
android:layout_height="fill_parent" 
android:layout_marginTop="30dip" 
android:orientation="vertical"> 

<Button 
    android:id="@+id/reg_button" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:onClick="clickButton" 
    android:text="RegButton" /> 

<!-- I WANT TO PUT CONTENT HERE ! --> 

</LinearLayout> 

試試這個它會工作100％。

Answer 2

您可以嘗試爲新添加的LinearLayout和Button添加寬度和高度參數嗎？創建視圖時需要這些參數。

這樣子。

newLinear.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));

Answer 3

test.setLayoutParams（新LinearLayout.LayoutParams（LayoutParams.LayoutParams.WRAP_CONTENT，LayoutParams.WRAP_CONTENT，1F））;

註釋行

setContentView（mainLayout）;