自定义控件二
上一篇博客讲到完全自定义的控件,这篇主要介绍将现有的控件组合起来,形成一个新的控件。
大致的流程差不多。以TagView为例,效果图如下图所示,一个ImageView和RadioButton组合在一起。
创建的步骤主要有以下几步:
1)创建TagView继承自ViewGroup;
public class TagView extends LinearLayout { public TagView(Context context, AttributeSet attrs) { super(context, attrs); //初始化 } public TagView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); //初始化 } }
2)自定义属性,并引入到xml文件当中;
自定义属性src
<?xml version="1.0" encoding="utf-8"?> <resources> <declare-styleable name="TagView"> <attr name="src" format="reference"/> </declare-styleable> </resources>
将src属性添加到布局文件当中,注意要添加自定义属性的命名空间
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main" 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="date.hb.com.tagview.MainActivity" xmlns:custom="http://schemas.android.com/apk/res-auto"> <date.hb.com.tagview.TagView android:layout_width="wrap_content" android:layout_height="wrap_content" custom:src="@mipmap/ic_launcher" /> </RelativeLayout>
3)读取属性;
private void initAttrs(AttributeSet attrs) { //读取属性 TypedArray typedArray = getContext().obtainStyledAttributes(attrs, R.styleable.TagView); imageSrc = typedArray.getDrawable(R.styleable.TagView_src); typedArray.recycle(); }
4)将各个控件排列,添加到ViewGroup当中;
private void initView(Context context) { this.setOrientation(LinearLayout.VERTICAL); imageView = new ImageView(context); imageView.setBackground(imageSrc); imageLayoutParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);//宽 高 imageLayoutParams.gravity = Gravity.CENTER_HORIZONTAL; addView(imageView, imageLayoutParams); radioButton = new RadioButton(context); radioLayoutParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); radioLayoutParams.gravity = Gravity.CENTER_HORIZONTAL; addView(radioButton, radioLayoutParams); }
完整的源码如下:
public class TagView extends LinearLayout { private Drawable imageSrc; private ImageView imageView; private RadioButton radioButton; private LayoutParams imageLayoutParams; private LayoutParams radioLayoutParams; public TagView(Context context, AttributeSet attrs) { super(context, attrs); initAttrs(attrs); initView(context); } public TagView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); initAttrs(attrs); initView(context); } private void initAttrs(AttributeSet attrs) { //读取属性 TypedArray typedArray = getContext().obtainStyledAttributes(attrs, R.styleable.TagView); imageSrc = typedArray.getDrawable(R.styleable.TagView_src); typedArray.recycle(); } @TargetApi(Build.VERSION_CODES.JELLY_BEAN) private void initView(Context context) { this.setOrientation(LinearLayout.VERTICAL); imageView = new ImageView(context); imageView.setBackground(imageSrc); imageLayoutParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);//宽 高 imageLayoutParams.gravity = Gravity.CENTER_HORIZONTAL; addView(imageView, imageLayoutParams); radioButton = new RadioButton(context); radioLayoutParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); radioLayoutParams.gravity = Gravity.CENTER_HORIZONTAL; addView(radioButton, radioLayoutParams); } }