居中GridView水平

Question

我有一個GridView，其中4個項目是動態添加的。我可以將它們居中放置，但不能水平放置。嘗試了一切......

main.xml中

... 
    <LinearLayout 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:gravity="center" 
     android:layout_gravity="center" > 

     <GridView 
     android:id="@+id/grid" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:columnWidth="90dp" 
     android:numColumns="auto_fit" 
     android:padding="10dp" 
     android:verticalSpacing="10dp" 
     android:horizontalSpacing="10dp" 
     android:stretchMode="spacingWidthUniform" 
     android:gravity="center" 
     android:listSelector="@drawable/card_button" > 

     </GridView> 

    </LinearLayout> 
... 

Items.xml

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

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id="@+id/btn" 
    android:layout_width="match_parent" 
    android:layout_height="90dp" 
    android:orientation="vertical" 
    android:gravity="center" > 

      <ImageButton 
       android:id="@+id/menuItem_img" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:src="@drawable/light" 
       android:contentDescription="@string/item" 
       android:background="#00000000" 
       android:tint="#222222" 
       android:paddingTop="8dp" 
       android:paddingBottom="4dp" /> 

      <TextView 
       android:id="@+id/menuItem_txt" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:textColor="#222222" 
       android:paddingBottom="8dp" 
       android:text="@string/item" 
       android:textSize="18sp" 
       android:singleLine="true" /> 

</LinearLayout> 

我不希望有這樣的Android列的固定數量：爲numColumns =」 auto_fit「必須留下。

Answer 1

我發現，它不可能與.XML
水平居中的GridView所以我不得不以編程方式做到這一點...這個答案對我幫助很大：https://stackoverflow.com/questions/6141910/android-center-gridview-horizontally

我不得不作出一些改變，使它的工作：

的GridView Adapter.java：

public Adapter(Context context, int width, int height, float density, GridView grid) { 
     this.context = context; 
     width_ = width; //get metrics.widthPixels from MainActivtiy.java 
     height_ = height; //get metrics.heightPixels from MainActivtiy.java 
     density_ = density; //get metrics.scaledDensity from MainActivtiy.java 
     grid_ = grid; //get GridView 

     Rect p = new Rect(); 
     grid_.getSelector().getPadding(p); 
     int selectorPadding = p.left + p.right; 
     int mSizePx = (int) Math.floor(90 * density_); //90 is my column width 
     int mSpacingPx = (int) Math.floor(10 * density_); //10 is space between columns 
     int numColumns = (int) Math.floor(1f * (width_ - selectorPadding + mSpacingPx)/(mSizePx + mSpacingPx)); 

     // CHANGES 
     int numbOfCol = menuValues.length; //menuValues (Array[]) are items you are adding to GridView 
     int contentWidth = 0; 
     //the most important part 
     if (numColumns > numbOfCol) { 
      contentWidth = numbOfCol * mSizePx; 
      contentWidth += (numbOfCol - 1) * mSpacingPx; 
      contentWidth += selectorPadding; 
     } else { 
      contentWidth = numColumns * mSizePx; 
      contentWidth += (numColumns - 1) * mSpacingPx; 
      contentWidth += selectorPadding; 
     }   
     int slack = width_ - contentWidth; 
     // 
     grid_.setNumColumns(numColumns); //set calculated number of collumns 
     grid_.setColumnWidth(mSizePx); //90 
     grid_.setVerticalSpacing(mSpacingPx); //10 
     grid_.setHorizontalSpacing(mSpacingPx); //10 

     //changed 
     grid_.setPadding(slack/2, mSpacingPx, slack/2, mSpacingPx); //I set top and bottom padding to 10dp (mSpacingPx) 

    } 

的main.xml（改變）：

... 
    <LinearLayout 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:gravity="center" 
     android:layout_gravity="center" > 

     <GridView 
     android:id="@+id/grid" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:stretchMode="none" 
     android:gravity="center" 
     android:listSelector="@drawable/card_button" 
     android:drawSelectorOnTop="true" > 

     </GridView> 

    </LinearLayout> 
...