Android的Elevation与TranslationZ探索

Elevation

表示视图控件所在的高度，值越大对应的阴影越大，看起来高度越高
###TranslationZ
同样表示视图控件所在的高度，但是其表示的是相对高度

例子

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.zxl.test_elevation.MainActivity">

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">
            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="0dp"
                android:layout_weight="1"
                android:orientation="horizontal"
                android:background="#3f51b5"
                android:elevation="2dp">

            LinearLayout>
            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="0dp"
                android:layout_weight="1"
                android:orientation="horizontal">

            LinearLayout>

        LinearLayout>

        <TextView
            android:id="@+id/tv"
            android:layout_width="80dp"
            android:layout_height="48dp"
            android:gravity="center"
            android:layout_gravity="center"
            android:text="test"
            android:background="#448aff"
            android:elevation="6dp"/>

    FrameLayout>LinearLayout>

public class MainActivity extends AppCompatActivity {

    private TextView tv;

    private boolean isSelected = false;

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

        tv = findViewById(R.id.tv);

        tv.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if(!isSelected){
                    isSelected = true;
                    tv.setTranslationZ(6);
                    System.out.println("zxl--->0--->"+tv.getElevation()+"--->"+tv.getTranslationZ());
                }else{
                    isSelected = false;
                    tv.setTranslationZ(-6);
                    System.out.println("zxl--->1--->"+tv.getElevation()+"--->"+tv.getTranslationZ());
                }
            }
        });
    }}

说明

        01-23 14:53:23.620 7029-7029/com.zxl.test_elevation I/System.out: zxl--->0--->6.0--->6.0
        01-23 14:53:30.678 7029-7029/com.zxl.test_elevation I/System.out: zxl--->1--->6.0--->-6.0

从程序运行后log可以看出
视图控件的整个高度值是Elevation+TranslationZ，当其值为0时则没有阴影了，当其值小于0在在上一个控件下方，当其值大于0则有阴影，从而出现高度。

标签：控件,Elevation,TranslationZ,tv,zxl,System,---,6.0,Android
来源： https://blog.51cto.com/u_15091798/2782931