自定义控件属性

来源：互联网发布：王心凌怎么消失了知乎编辑：程序博客网时间：2024/06/05 16:46

demo：defineView

1.如何自定义控件属性?

2.如何动态创建组件？

3.接口回调思想

设计需要的属性

values新建attrs.xml。通过<declare-styleable>来告诉系统这是自定义的属性

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name ="Topbar">
        <attr name = "title" format="string"/>
        <attr name = "titleSize" format = "dimension"/>
        <attr name = "titleTextColor" format = "color"/>
        <attr name = "leftTextColor" format="color"/>
        <attr name = "leftBackground" format = "reference|color"/>
        <attr name = "leftText" format = "string"/>
        <attr name = "rightTextColor" format="color"/>
        <attr name = "rightBackground" format = "reference|color"/>
        <attr name = "rightText" format = "string"/>       
    </declare-styleable>
</resources>

实现一个自定义的“View”
重写构造方法，在构造方法中取出自定义值存到TapeArray中，从TypeArray中取出相应的值给了相应的变量，然后组合控件并添加到

ViewGroup中，所有布局属性都在里面设置。

public class Topbar extends RelativeLayout {
private Button leftButton,rightButton;
private TextView tvText;
/**
 * 左边字体的颜色
 */
private int leftTextColor;
/**
 * 左边背景的颜色
 */
private Drawable leftBackground;
/**
 * 左边butto文字
 */
private String leftText;
/**
 * 右边字体的颜色
 */
private int rightTextColor;
/**
 * 右边背景的颜色
 */
private Drawable rightBackground;
/**
 * 右边butto文字
 */
private String rightText;
/**
 * title要显示文字的大小
 */
private float titleTextSize;
/**
 * title字体的颜色
 */
private int titleTextColor;
/**
 * title的文字
 */
private String title;
private LayoutParams leftParams,rightParams,titleParams;
private topbarClickListener listener;
/**
 * 实现自己的接口
 * @author Kevin
 *
 */
public interface topbarClickListener{
public void leftClick();
public void rightClick();
}
/**
 * 将传进来的映射
 * @param listener
 */
public void setOnTopClickListener(topbarClickListener listener){
this.listener = listener;
}
    //需要自定义属性，所以需要attrs参数
public Topbar(Context context, AttributeSet attrs) {
super(context, attrs);
//存取自定义属性中的值返回到TypedArray
TypedArray ta = context.obtainStyledAttributes(attrs,R.styleable.Topbar);
//完成属性赋值
leftTextColor = ta.getColor(R.styleable.Topbar_leftTextColor, 0);
leftBackground = ta.getDrawable(R.styleable.Topbar_leftBackground);
rightText = ta.getString(R.styleable.Topbar_rightText);
rightTextColor = ta.getColor(R.styleable.Topbar_rightTextColor, 0);
rightBackground = ta.getDrawable(R.styleable.Topbar_rightBackground);
leftText = ta.getString(R.styleable.Topbar_leftText);
titleTextSize = ta.getDimension(R.styleable.Topbar_titleSize,0);
titleTextColor = ta.getColor(R.styleable.Topbar_titleTextColor,0);
title = ta.getString(R.styleable.Topbar_title);
//TypedArray一定要回收，避免浪费资源和由于缓存造成的错误
ta.recycle();
leftButton = new Button(context);
rightButton = new Button(context);
tvText = new TextView(context);
//自定义属性赋值给自定义的控件
leftButton.setTextColor(leftTextColor);
leftButton.setBackgroundDrawable(leftBackground);
leftButton.setText(leftText);
rightButton.setTextColor(rightTextColor);
rightButton.setBackgroundDrawable(rightBackground);
rightButton.setText(rightText);
tvText.setTextColor(titleTextColor);
tvText.setTextSize(titleTextSize);
tvText.setText(title);
tvText.setGravity(Gravity.CENTER);
setBackgroundColor(0xFFF59563);
//设置布局参数
leftParams = new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
//居左对齐
leftParams.addRule(RelativeLayout.ALIGN_PARENT_LEFT,TRUE);
//以leftParams的方式添加进去
addView(leftButton,leftParams);
//设置布局参数
rightParams = new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
//居右对齐
rightParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT,TRUE);
addView(rightButton,rightParams);
titleParams = new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.MATCH_PARENT);
titleParams.addRule(RelativeLayout.CENTER_IN_PARENT,TRUE);
addView(tvText,titleParams);
leftButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
listener.leftClick();
}
});
rightButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
listener.rightClick();
}
});
}
}

接口回调抽象了使用的方法，点击事件抽象了出来，让调用者决定到底做什么，topbar就被封装起来了。

引用“View”

xmlns是命名空间，需要添加命名空间来引用自己的属性，AS中auto就行，Eclipse需要完整的包名。

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:custom="http://schemas.android.com/apk/res/com.llc.defineview"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.llc.defineview.MainActivity" >
    <com.llc.defineview.Topbar 
        android:id="@+id/topbar"
        android:layout_width="match_parent"
        android:layout_height="40dp"
        custom:leftBackground="@drawable/back_bg"
        custom:leftText="back"
        custom:leftTextColor="#ffffff"
        custom:rightBackground="@drawable/edit_bg"
        custom:rightText="more"
        custom:rightTextColor="#ffffff"
        custom:title="自定义标题"
        custom:titleTextColor="#123421"
        custom:titleSize="10sp">      
    </com.llc.defineview.Topbar>
</RelativeLayout>

MainActivity.java

public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Topbar topbar = (Topbar) findViewById(R.id.topbar);
        topbar.setOnTopClickListener(new Topbar.topbarClickListener() {
@Override
public void rightClick() {
Toast.makeText(MainActivity.this, "left", Toast.LENGTH_LONG).show();
}
@Override
public void leftClick() {
Toast.makeText(MainActivity.this, "right", Toast.LENGTH_LONG).show();
}
});
    }
}

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