Question

我想让视图在另一个视图前移动。我使用相对布局，以便z顺序如下工作。

activity_main.xml中：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    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=".MainActivity" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="match_parent"
        android:layout_height="300dp" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="200dp"
        android:layout_height="300dp"
        android:text="."
        android:textSize="200dp" />

</RelativeLayout>

MainActivity.java：当用户触摸textView1时，textView2根据触摸事件的X移动。

public class MainActivity extends Activity implements View.OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        TextView textView1 = (TextView) findViewById(R.id.textView1);
        final TextView textView2 = (TextView) findViewById(R.id.textView2);

        textView1.setBackgroundColor(Color.GREEN);

        textView1.setOnTouchListener(new OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                textView2.setLeft((int) event.getX());
                return true;
            }
        });
    }

    @Override
    public void onClick(View arg0) {

    }
}

但是textView2奇怪地消失在某个X坐标之外（好像它落在一个看不见的第三个视图后面），如下所示：

The beginning:
+-------------------------------+
|                               |
|   +----+                      |
|   |    |                      |
|   |    |                      |
|   +----+                      |
|                               |
+-------------------------------+

Moving to the right..
+-------------------------------+
|                               |
|       +----+                  |
|       |    |                  |
|       |    |                  |
|       +----+                  |
|                               |
+-------------------------------+

.. and starts to disappear at a certain X.
+-------------------------------+
|                               |
|              +--              |
|              |                |
|              |                |
|              +--              |
|                               |
+-------------------------------+

有什么问题？

Answer 1

你的填充权是不是太重要了：

android:paddingRight="@dimen/activity_horizontal_margin"

您确定使用setLeft()是个好主意吗？也许，最好通过LayoutParam？

LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
params.setMargins(event.getX(), 0, 0, 0);
textView2.setLayoutParams(params);

当超出某个X坐标时，视图会消失

1 个答案: