Android 以编程方式更改视图的重力和大小

我想以编程方式更改视图（CanvasView扩展视图）的大小，以保持重力。我的观点是相对的。我尝试了很多不同的方法，但我被卡住了

重点是，我想根据屏幕大小设置大小：

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        ToolsAndConstants.metrics = new DisplayMetrics();

        windowManager =  (WindowManager) getSystemService(Context.WINDOW_SERVICE);
        windowManager.getDefaultDisplay().getMetrics(ToolsAndConstants.metrics);

        setContentView(R.layout.activity_dictionary);

        CanvasView canvasView = (CanvasView) findViewById(R.id.activity_dictionary_CanvasView);
        canvasView.canvasWidth  = (ToolsAndConstants.metrics.widthPixels / 10 * 7) - 10;
        canvasView.canvasHeight = (ToolsAndConstants.metrics.heightPixels / 10 * 4) - 10; 
        canvasView.setLayoutParams(new RelativeLayout.LayoutParams(canvasView.canvasWidth, canvasView.canvasHeight));

    (...)
    }

XML文件：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_dictionary_relativeLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/gray_patterns_vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".LogReader" >

    <LinearLayout
        android:id="@+id/activity_dictionary_linearLayout1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_centerHorizontal="true"
        android:gravity="center_vertical|center_horizontal"
        android:orientation="vertical" >

        <ProgressBar
            android:id="@+id/activity_dictionary_progressBar1"
            style="?android:attr/progressBarStyleLarge"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal" />

        <TextView
            android:id="@+id/activity_dictionary_textView1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:text="Loading dictionary..."
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:textColor="@android:color/white" />
    </LinearLayout>

    <FrameLayout
        android:id="@+id/activity_dictionary_frameLayout1"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true" >

        <view
            android:id="@+id/activity_dictionary_CanvasView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="0dp"
            android:layout_alignParentBottom="true"
            android:layout_centerHorizontal="true"
            class="com.example.dictionary.CanvasView"
            android:orientation="vertical" />
    </FrameLayout>

</RelativeLayout>

---

如何调整大小？

我找到了解决方案：

canvasView = (CanvasView) findViewById(R.id.activity_dictionary_CanvasView);
canvasView.canvasWidth  = 100;
canvasView.canvasHeight = 100;
RelativeLayout.LayoutParams layoutParams = 
         new RelativeLayout.LayoutParams(canvasView.canvasWidth, canvasView.canvasHeight);
//I want my Canvas be above LinearLayout and Horizontaly centered
layoutParams.addRule(RelativeLayout.CENTER_HORIZONTAL);
layoutParams.addRule(RelativeLayout.ABOVE, R.id.activity_dictionary_linearLayout2);
canvasView.setLayoutParams(layoutParams);

---

问题是什么？您可能不需要向fl添加参数。如果您试图在rl中设置视图的位置，则使用view.setX（number）；和视图。setY（数字）；。这将设置它们，然后使用view.setLayoutParams（新的LayoutParams（宽度、高度））；设置视图的大小。在测量和布局通过后，何时在视图上调用requestLayout？问题是，当我不改变程序内部的大小时，我的视图在屏幕底部可见，水平居中。我想要的是让它在底部水平居中，但更大。但是当我改变它的大小时，它会出现在相对布局的左上角……是否有类似于android:Layout\u alignParentBottom=“true”的东西我可以在代码中编写_