Android：如何将imageView设置为水平居中

Question

我想在Layout水平居中放置一个View 。 我下面的代码失败。 我怎样才能解决这个问题？

看我的代码：

LinearLayout LLT = new LinearLayout(context);
LLT.setOrientation(LinearLayout.VERTICAL);
LLT.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));

//get booktheme by bookID 
theme = db.getthemeByID(id);
String themePath = theme.getFilepath();
int resid = getResources().getIdentifier(themePath, "drawable", getPackageName());
//imageView
ImageView imageTheme = new ImageView(context);
imageTheme.setLayoutParams(new LayoutParams(500, 700));
imageTheme.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
imageTheme.setPadding(0, 20, 0, 10);
imageTheme.setAdjustViewBounds(true);
imageTheme.setImageResource(resid);

LLT.addView(imageTheme);
// add view 
VF.addView(LLT);

Answer 1

您是否尝试过使用相对布局而不是线性布局？

编辑：如果您想使用相对布局，

RelativeLayout.LayoutParams layoutParams = 
    (RelativeLayout.LayoutParams)imageview.getLayoutParams();
layoutParams.addRule(RelativeLayout.CENTER_HORIZONTAL, RelativeLayout.TRUE);
imageview.setLayoutParams(layoutParams);

（没有测试代码顺便说一句，但我在我的一个应用程序中使用了它，所以这可以做到）

Answer 2

在LayoutParams使用Gravity功能，如下所示：

LinearLayout.LayoutParams layoutParams=new LinearLayout.LayoutParams(500, 700);
layoutParams.gravity=Gravity.CENTER_HORIZONTAL;
imageTheme.setLayoutParams(layoutParams);

用此代码替换您的代码，然后尝试：

LinearLayout LLT = new LinearLayout(context);
    LLT.setOrientation(LinearLayout.VERTICAL);
    LLT.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));



    //get booktheme by bookID 
    theme = db.getthemeByID(id);
    String themePath = theme.getFilepath();
    int resid = getResources().getIdentifier(themePath, "drawable", getPackageName());
    //imageView
    ImageView imageTheme = new ImageView(context);
    LinearLayout.LayoutParams layoutParams=new LinearLayout.LayoutParams(500, 700);
    layoutParams.gravity=Gravity.CENTER_HORIZONTAL;
    imageTheme.setLayoutParams(layoutParams);
    imageTheme.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
    imageTheme.setPadding(0, 20, 0, 10);
    imageTheme.setAdjustViewBounds(true);
    imageTheme.setImageResource(resid);

    LLT.addView(imageTheme);
    // add view 
    VF.addView(LLT);