本文实例讲述了Android自定义ViewPager的方法。分享给大家供大家参考，具体如下：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
|
package com.rong.activity;import android.content.Context;import android.graphics.Color;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.VelocityTracker;import android.view.View;import android.view.ViewGroup;import android.widget.LinearLayout;import android.widget.Scroller;public class CustomViewPager extends ViewGroup { private Context mContext; private int screenWidth; private int screenHight; private int lastMoveX = 0; private VelocityTracker velocityTracker; private int MAX_VELOCITY=600; private int curScreen=0; private Scroller scroller; public CustomViewPager(Context context) { super(context); mContext = context; initView(); } public CustomViewPager(Context context, AttributeSet attrs) { super(context, attrs); mContext = context; initView(); } public CustomViewPager(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); mContext = context; initView(); } @Override public boolean onTouchEvent(MotionEvent event) { if (velocityTracker == null) { velocityTracker = VelocityTracker.obtain(); } velocityTracker.addMovement(event); int x = (int) event.getX(); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: lastMoveX = x; break; case MotionEvent.ACTION_MOVE: int dis = lastMoveX - x; scrollBy(dis, 0); lastMoveX = x; break; case MotionEvent.ACTION_UP: velocityTracker.computeCurrentVelocity(1000); int velocityX=(int)velocityTracker.getXVelocity(); if(velocityX>MAX_VELOCITY&&curScreen>0){ jump2Screen(curScreen-1); }else if(velocityX<-MAX_VELOCITY&&curScreen<getChildCount()-1){ jump2Screen(curScreen+1); }else{ int screen=(getScrollX()+screenWidth/2)/screenWidth; jump2Screen(screen); } if (velocityTracker != null) { velocityTracker.recycle(); velocityTracker = null; } break; } return true; } /** * 跳转到指定Screen * @param screen */ public void jump2Screen(int screen){ curScreen=screen; if(curScreen>getChildCount()-1){ curScreen=getChildCount()-1; } int dis=curScreen*screenWidth-getScrollX(); scroller.startScroll(getScrollX(), 0, dis, 0); invalidate(); } @Override public void computeScroll() { if(scroller.computeScrollOffset()){ scrollTo(scroller.getCurrX(), 0); postInvalidate(); } } public void initView() { scroller=new Scroller(mContext); LinearLayout layout1 = new LinearLayout(getContext()); layout1.setBackgroundColor(Color.RED); addView(layout1); LinearLayout layout2 = new LinearLayout(getContext()); layout2.setBackgroundColor(Color.GREEN); addView(layout2); LinearLayout layout3 = new LinearLayout(getContext()); layout3.setBackgroundColor(Color.BLUE); addView(layout3); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); screenWidth = MeasureSpec.getSize(widthMeasureSpec); screenHight = MeasureSpec.getSize(heightMeasureSpec); setMeasuredDimension(screenWidth, screenHight); for (int i = 0; i < getChildCount(); i++) { View view = getChildAt(i); view.measure(screenWidth, screenHight); } } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { int leftWidth = 0; for (int i = 0; i < getChildCount(); i++) { View view = getChildAt(i); view.layout(leftWidth, 0, leftWidth + screenWidth, screenHight); leftWidth = leftWidth + screenWidth; } }} |
希望本文所述对大家Android程序设计有所帮助。
