Android自定义可复用View——topbar

最新推荐文章于 2019-01-05 18:39:58 发布

Pugham

最新推荐文章于 2019-01-05 18:39:58 发布

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本文介绍如何在Android应用中创建自定义Topbar组件，包括定义XML属性、实现Java类及在布局文件中的使用方法。

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1.自定义属性，创建attrs.xml

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

2.自定义Layout，Topbar.java

package com.example.mytopbar;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ListAdapter;
import android.widget.RelativeLayout;
import android.widget.TextView;

/**
 * Created by Zac on 2016/10/7.
 */

public class Topbar extends RelativeLayout {

    private TextView titleTv;
    private Button leftBtn;
    private Button rightBtn;

    private Drawable barBackground;

    private String titleText;
    private float titleTextSize;
    private int titleTextColor;

    private String leftText;
    private int leftTextColor;
    private Drawable leftBackground;

    private String rightText;
    private int rightTextColor;
    private Drawable rightBackground;

    private LayoutParams titleParams, leftParams, rightParams;

    private topBarClickListener listener;

    public interface topBarClickListener {
        public void leftBtnClick();
        public void rightBtnClick();
    }

    public void setOnTopbarClickListener(topBarClickListener listener) {
        this.listener = listener;
    }

    public Topbar(Context context, AttributeSet attrs) {
        super(context, attrs);

        TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.Topbar);
        barBackground = ta.getDrawable(R.styleable.Topbar_barBackground);
        titleText = ta.getString(R.styleable.Topbar_titleText);
        titleTextSize = ta.getDimension(R.styleable.Topbar_titleTextSize, 0);
        titleTextColor = ta.getColor(R.styleable.Topbar_titleTextColor, 0);
        leftText = ta.getString(R.styleable.Topbar_leftText);
        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);
        ta.recycle();

        titleTv = new TextView(context);
        leftBtn = new Button(context);
        rightBtn = new Button(context);

        titleTv.setText(titleText);
        titleTv.setTextSize(titleTextSize);
        titleTv.setTextColor(titleTextColor);
        titleTv.setGravity(Gravity.CENTER);

        leftBtn.setText(leftText);
        leftBtn.setTextColor(leftTextColor);
        leftBtn.setBackground(leftBackground);

        rightBtn.setText(rightText);
        rightBtn.setTextColor(rightTextColor);
        rightBtn.setBackground(rightBackground);

        setBackground(barBackground);

        titleParams = new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.MATCH_PARENT);
        titleParams.addRule(RelativeLayout.CENTER_IN_PARENT, TRUE);

        leftParams = new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        leftParams.addRule(RelativeLayout.ALIGN_PARENT_LEFT, TRUE);

        rightParams = new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        rightParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT, TRUE);

        addView(titleTv, titleParams);
        addView(leftBtn, leftParams);
        addView(rightBtn, rightParams);

        leftBtn.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                listener.leftBtnClick();
            }
        });

        rightBtn.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                listener.rightBtnClick();
            }
        });
    }

    public void setLeftBtnVisible(boolean flag) {
        if (flag) {
            leftBtn.setVisibility(View.VISIBLE);
        } else {
            leftBtn.setVisibility(View.GONE);
        }
    }

    public void setRightBtnVisible(boolean flag) {
        if (flag) {
            rightBtn.setVisibility(View.VISIBLE);
        } else {
            rightBtn.setVisibility(View.GONE);
        }
    }
}

3.布局文件中设置属性

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:custom="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="5dp"
    tools:context="com.example.mytopbar.MainActivity">

    <com.example.mytopbar.Topbar
        android:id="@+id/topbar"
        android:layout_width="match_parent"
        android:layout_height="40dp"
        custom:barBackground="#333333"
        custom:titleText="自定义标题"
        custom:titleTextSize="10sp"
        custom:titleTextColor="#123412"
        custom:leftText="Back"
        custom:leftTextColor="#FFFFFF"
        custom:leftBackground="#333333"
        custom:rightText="More"
        custom:rightTextColor="#FFFFFF"
        custom:rightBackground="#333333">
    </com.example.mytopbar.Topbar>
    
</RelativeLayout>

4.引用topbar

package com.example.mytopbar;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

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

        Topbar topbar = (Topbar) findViewById(R.id.topbar);
        topbar.setOnTopbarClickListener(new Topbar.topBarClickListener() {
            @Override
            public void leftBtnClick() {
                Toast.makeText(MainActivity.this, "HelloLeft", Toast.LENGTH_SHORT).show();
            }

            @Override
            public void rightBtnClick() {
                Toast.makeText(MainActivity.this, "HelloRight", Toast.LENGTH_SHORT).show();
            }
        });
    }
}