Android自定义View实现垂直时间轴布局

时间轴，顾名思义就是将发生的事件按照时间顺序罗列起来，给用户带来一种更加直观的体验。京东和淘宝的物流顺序就是一个时间轴，想必大家都不陌生，如下图：

分析

实现这个最常用的一个方法就是用ListView，我这里用继承LinearLayout的方式来实现。首先定义了一些自定义属性：

attrs.xml

TimelineLayout.java

package com.jackie.timeline; 
 
import android.content.Context; 
import android.content.res.TypedArray; 
import android.graphics.Bitmap; 
import android.graphics.Canvas; 
import android.graphics.Paint; 
import android.graphics.drawable.BitmapDrawable; 
import android.support.annotation.Nullable; 
import android.util.AttributeSet; 
import android.view.View; 
import android.widget.LinearLayout; 
 
/** 
 * Created by Jackie on 2017/3/8. 
 * 时间轴控件 
 */ 
 
public class TimelineLayout extends LinearLayout { 
  private Context mContext; 
 
  private int mLineMarginLeft; 
  private int mLineMarginTop; 
  private int mLineStrokeWidth; 
  private int mLineColor;; 
  private int mPointSize; 
  private int mPointColor; 
  private Bitmap mIcon; 
 
  private Paint mLinePaint; //线的画笔 
  private Paint mPointPaint; //点的画笔 
   
 
  //第一个点的位置 
  private int mFirstX; 
  private int mFirstY; 
  //最后一个图标的位置 
  private int mLastX; 
  private int mLastY; 
 
  public TimelineLayout(Context context) { 
    this(context, null); 
  } 
 
  public TimelineLayout(Context context, @Nullable AttributeSet attrs) { 
    this(context, attrs, 0); 
  } 
 
  public TimelineLayout(Context context, @Nullable AttributeSet attrs, int defStyleAttr) { 
    super(context, attrs, defStyleAttr); 
    TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.TimelineLayout); 
    mLineMarginLeft = ta.getDimensionPixelOffset(R.styleable.TimelineLayout_line_margin_left, 10); 
    mLineMarginTop = ta.getDimensionPixelOffset(R.styleable.TimelineLayout_line_margin_top, 0); 
    mLineStrokeWidth = ta.getDimensionPixelOffset(R.styleable.TimelineLayout_line_stroke_width, 2); 
    mLineColor = ta.getColor(R.styleable.TimelineLayout_line_color, 0xff3dd1a5); 
    mPointSize = ta.getDimensionPixelSize(R.styleable.TimelineLayout_point_size, 8); 
    mPointColor = ta.getDimensionPixelOffset(R.styleable.TimelineLayout_point_color, 0xff3dd1a5); 
 
    int iconRes = ta.getResourceId(R.styleable.TimelineLayout_icon_src, R.drawable.ic_ok); 
    BitmapDrawable drawable = (BitmapDrawable) context.getResources().getDrawable(iconRes); 
    if (drawable != null) { 
      mIcon = drawable.getBitmap(); 
    } 
 
    ta.recycle(); 
 
    setWillNotDraw(false); 
    initView(context); 
  } 
 
  private void initView(Context context) { 
    this.mContext = context; 
 
    mLinePaint = new Paint(); 
    mLinePaint.setAntiAlias(true); 
    mLinePaint.setDither(true); 
    mLinePaint.setColor(mLineColor); 
    mLinePaint.setStrokeWidth(mLineStrokeWidth); 
    mLinePaint.setStyle(Paint.Style.FILL_AND_STROKE); 
 
    mPointPaint = new Paint(); 
    mPointPaint.setAntiAlias(true); 
    mPointPaint.setDither(true); 
    mPointPaint.setColor(mPointColor); 
    mPointPaint.setStyle(Paint.Style.FILL); 
  } 
 
  @Override 
  protected void onDraw(Canvas canvas) { 
    super.onDraw(canvas); 
     
    drawTimeline(canvas); 
  } 
 
  private void drawTimeline(Canvas canvas) { 
    int childCount = getChildCount(); 
 
    if (childCount > 0) { 
      if (childCount > 1) { 
        //大于1，证明至少有2个，也就是第一个和第二个之间连成线，第一个和最后一个分别有点和icon 
        drawFirstPoint(canvas); 
        drawLastIcon(canvas); 
        drawBetweenLine(canvas); 
      } else if (childCount == 1) { 
        drawFirstPoint(canvas); 
      } 
    } 
  } 
 
  private void drawFirstPoint(Canvas canvas) { 
    View child = getChildAt(0); 
    if (child != null) { 
      int top = child.getTop(); 
      mFirstX = mLineMarginLeft; 
      mFirstY = top + child.getPaddingTop() + mLineMarginTop; 
 
      //画圆 
      canvas.drawCircle(mFirstX, mFirstY, mPointSize, mPointPaint); 
    } 
  } 
 
  private void drawLastIcon(Canvas canvas) { 
    View child = getChildAt(getChildCount() - 1); 
    if (child != null) { 
      int top = child.getTop(); 
      mLastX = mLineMarginLeft; 
      mLastY = top + child.getPaddingTop() + mLineMarginTop; 
 
      //画图 
      canvas.drawBitmap(mIcon, mLastX - (mIcon.getWidth() >> 1), mLastY, null); 
    } 
  } 
 
  private void drawBetweenLine(Canvas canvas) { 
    //从开始的点到最后的图标之间，画一条线 
    canvas.drawLine(mFirstX, mFirstY, mLastX, mLastY, mLinePaint); 
    for (int i = 0; i < getChildCount() - 1; i++) { 
      //画圆 
      int top = getChildAt(i).getTop(); 
      int y = top + getChildAt(i).getPaddingTop() + mLineMarginTop; 
      canvas.drawCircle(mFirstX, y, mPointSize, mPointPaint); 
    } 
  } 
 
  public int getLineMarginLeft() { 
    return mLineMarginLeft; 
  } 
 
  public void setLineMarginLeft(int lineMarginLeft) { 
    this.mLineMarginLeft = lineMarginLeft; 
    invalidate(); 
  } 
} 

从上面的代码可以看出，分三步绘制，首先绘制开始的实心圆，然后绘制结束的图标，然后在开始和结束之间先绘制一条线，然后在线上在绘制每个步骤的实心圆。
activity_main.xml

MainActivity.java

package com.jackie.timeline; 
 
import android.os.Bundle; 
import android.support.v7.app.AppCompatActivity; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.widget.Button; 
import android.widget.TextView; 
 
public class MainActivity extends AppCompatActivity implements View.OnClickListener { 
  private Button addItemButton; 
  private Button subItemButton; 
  private Button addMarginButton; 
  private Button subMarginButton; 
  private TextView mCurrentMargin; 
 
  private TimelineLayout mTimelineLayout; 
 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
 
    initView(); 
  } 
 
  private void initView() { 
    addItemButton = (Button) findViewById(R.id.add_item); 
    subItemButton = (Button) findViewById(R.id.sub_item); 
    addMarginButton= (Button) findViewById(R.id.add_margin); 
    subMarginButton= (Button) findViewById(R.id.sub_margin); 
    mCurrentMargin= (TextView) findViewById(R.id.current_margin); 
    mTimelineLayout = (TimelineLayout) findViewById(R.id.timeline_layout); 
 
    addItemButton.setOnClickListener(this); 
    subItemButton.setOnClickListener(this); 
    addMarginButton.setOnClickListener(this); 
    subMarginButton.setOnClickListener(this); 
  } 
 
  private int index = 0; 
  private void addItem() { 
    View view = LayoutInflater.from(this).inflate(R.layout.item_timeline, mTimelineLayout, false); 
    ((TextView) view.findViewById(R.id.tv_action)).setText("步骤" + index); 
    ((TextView) view.findViewById(R.id.tv_action_time)).setText("2017年3月8日16:55:04"); 
    ((TextView) view.findViewById(R.id.tv_action_status)).setText("完成"); 
    mTimelineLayout.addView(view); 
    index++; 
  } 
 
  private void subItem() { 
    if (mTimelineLayout.getChildCount() > 0) { 
      mTimelineLayout.removeViews(mTimelineLayout.getChildCount() - 1, 1); 
      index--; 
    } 
  } 
 
  @Override 
  public void onClick(View v) { 
    switch (v.getId()){ 
      case R.id.add_item: 
        addItem(); 
        break; 
      case R.id.sub_item: 
        subItem(); 
        break; 
      case R.id.add_margin: 
        int currentMargin = UIHelper.pxToDip(this, mTimelineLayout.getLineMarginLeft()); 
        mTimelineLayout.setLineMarginLeft(UIHelper.dipToPx(this, ++currentMargin)); 
        mCurrentMargin.setText("current line margin left is " + currentMargin + "dp"); 
        break; 
      case R.id.sub_margin: 
        currentMargin = UIHelper.pxToDip(this, mTimelineLayout.getLineMarginLeft()); 
        mTimelineLayout.setLineMarginLeft(UIHelper.dipToPx(this, --currentMargin)); 
        mCurrentMargin.setText("current line margin left is " + currentMargin + "dp"); 
        break; 
      default: 
        break; 
    } 
  } 
} 

item_timeline.xml

附上像素工具转化的工具类：

package com.jackie.timeline; 
 
import android.content.Context; 
 
/** 
 * Created by Jackie on 2017/3/8. 
 */ 
public final class UIHelper { 
 
  private UIHelper() throws InstantiationException { 
    throw new InstantiationException("This class is not for instantiation"); 
  } 
 
  /** 
   * dip转px 
   */ 
  public static int dipToPx(Context context, float dip) { 
    return (int) (dip * context.getResources().getDisplayMetrics().density + 0.5f); 
  } 
 
  /** 
   * px转dip 
   */ 
  public static int pxToDip(Context context, float pxValue) { 
    final float scale = context.getResources().getDisplayMetrics().density; 
    return (int) (pxValue / scale + 0.5f); 
  } 
} 

效果图如下：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。