Android - 自定义控件_android 自定义控件

1. 添加自定义Layout

custom_item.xml 代码：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/item_image"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:adjustViewBounds="true"
        android:layout_marginLeft="5dp"
        android:layout_marginRight="5dp"
        android:scaleType="centerInside" />

    <TextView
        android:id="@+id/item_text"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:gravity="center_vertical" />

</LinearLayout>
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2. 添加自定义控件的类

CustomItem.java 代码：

public class CustomItem extends FrameLayout {

    private Context mContext;
    private View mView;
    private ImageView mItemImage;
    private TextView mItemText;

    public CustomItem(@NonNull Context context) {
        super(context);
        init(context, null);
    }

    public CustomItem(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        init(context, attrs);
    }

    public CustomItem(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs);
    }

    public CustomItem(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        init(context, attrs);
    }

    private void init(Context context, AttributeSet attrs){
        mContext = context;

        LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        mView = inflater.inflate(R.layout.custom_item, this, true);

        mItemImage = findViewById(R.id.item_image);
        mItemText = findViewById(R.id.item_text);

    }

}
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3. 自定义控件的属性

3.1 添加 attrs_custom_item.xml

<resources>
    <declare-styleable name="CustomItem">
        <attr name="custom_item_text" format="string" />
        <attr name="custom_item_image" format="color|reference" />
    </declare-styleable>
</resources>
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3.2 CustomItem.java类中添加属性的处理

CustomItem.java类最终代码为：

public class CustomItem extends FrameLayout {

    private Context mContext;
    private View mView;
    private ImageView mItemImage;
    private TextView mItemText;

    public CustomItem(@NonNull Context context) {
        super(context);
        init(context, null);
    }

    public CustomItem(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        init(context, attrs);
    }

    public CustomItem(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs);
    }

    public CustomItem(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        init(context, attrs);
    }

    private void init(Context context, AttributeSet attrs){
        mContext = context;

        LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        mView = inflater.inflate(R.layout.custom_item, this, true);

        mItemImage = findViewById(R.id.item_image);
        mItemText = findViewById(R.id.item_text);

        TypedArray a = mContext.obtainStyledAttributes(attrs, R.styleable.CustomItem);
        mItemText.setText(a.getString(R.styleable.CustomItem_custom_item_text));
        mItemImage.setImageResource(a.getResourceId(R.styleable.CustomItem_custom_item_image, R.drawable.image3));
    }

}
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4. 在activity_main.xml中添加自定义控件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <com.example.customview.CustomItem
        android:layout_width="match_parent"
        android:layout_height="40dp"
        app:custom_item_text="第一行"
        app:custom_item_image="@drawable/image1"/>

    <com.example.customview.CustomItem
        android:layout_width="match_parent"
        android:layout_height="40dp"
        app:custom_item_text="第二行"
        app:custom_item_image="@drawable/image2"/>

</LinearLayout>
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5. 效果

6. 代码

https://gitee.com/jie-xio/android_samples/tree/master/CustomControl

7. 更优步骤

以上添加自定义 custom_item.xml、CustomItem.java、attrs_custom_item.xml 的步骤，在Android studio中有简洁的步骤，自动创建这些文件：


自动会添加上这些文件，自己只需要按照本文上面的相应内容做修改即可