按钮：

按钮背景图片选择器

 res: drawable---new ----drawanle resource file --- btn_select

插入背景图片

res:   new   ----image asset

btn_select.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:drawable="@drawable/ic_launcher_foreground_1" android:state_pressed="true"/>

    <item android:drawable="@drawable/ic_launcher_foreground_2"/>


selector>

按钮颜色选择器：res:new    ---- directory---color   ----new -----drawanle resource file --- btn_color_select

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

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:color="#ffff0000" android:state_pressed="true"/>
    <item android:color="#ff00ff00"/>

selector>

button事件处理：

 EditText:

 <EditText
        android:id="@+id/et"

        android:hint="请输入用户名"
        android:textColor="#95a1aa"
        android:inputType="phone"
        android:drawableLeft="@drawable/ic_launcher_foreground"
        android:drawablePadding="20dp"
        android:background="@color/white"
        android:paddingLeft="20dp"
        android:layout_width="400dp"
        android:layout_height="100dp"/>
    <Button
        android:id="@+id/btn"
        android:text="获取用户名"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

private EditText et;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button btn = findViewById(R.id.btn);
        et = findViewById(R.id.et);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String text = et.getText().toString();
                Log.e("leo", "输入的内容: " +text);
            }
        });

ImageView:

缩放类型：

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