Android跑马灯控件,可水平滚动和垂直滚动

释放双眼,带上耳机,听听看~!

水平滚动:从右往左。

垂直滚动:从下往上。

先来张效果图:

控件源码:

package com.otess.marquee;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.text.TextUtils;
import android.util.AttributeSet;
import java.util.ArrayList;
import java.util.List;
/**
* Author:SkySmile
* Date:2020/1/14
* Description:跑马灯效果的View,目前可以从下往上、从右往左滚动
*/
public class MarqueeView extends android.support.v7.widget.AppCompatTextView {
//滚动方向
//不滚动
public static final int SCROLL_NO = 1;
//从下往上
public static final int SCROLL_BT = 2;
//从右往左
public static final int SCROLL_RL = 3;
//滚动速度
//慢速
public static final int SPEED_SLOW = 4;
//中速
public static final int SPEED_NORMAL = 5;
//快速
public static final int SPEED_FAST = 6;
//特快
public static final int SPEED_EXPRESS = 7;
//垂直滚动需要的数据
private float lineSpace;
private float verticalSpeed = 0.1f;
private List<String> textList = new ArrayList<>();
private StringBuilder textBuilder = new StringBuilder();
//水平滚动需要的数据
private float horizontalSpeed = 2f;
private Rect rect;
private Paint paint;
//默认不滚动
private int scrollType;
//每次更滚动的距离
private float scrollStep = 0f;
public MarqueeView(Context context) {
this(context, null);
}
public MarqueeView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public MarqueeView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.MarqueeView);
scrollType = array.getInt(R.styleable.MarqueeView_scrollType, SCROLL_NO);
int scrollSpeed = array.getInt(R.styleable.MarqueeView_speedType, SPEED_NORMAL);
int color = array.getColor(R.styleable.MarqueeView_textColor, 0x000000);
lineSpace = array.getInt(R.styleable.MarqueeView_lineSpace, 0);
array.recycle();
setSpeedType(scrollSpeed);
paint = getPaint();
paint.setColor(color);
rect = new Rect();
}
@Override
public void setTextColor(int color) {
super.setTextColor(color);
paint.setColor(color);
}
/**
* 设置滚动方向
*
* @param scrollType 滚动方向
*/
public void setScrollType(int scrollType) {
this.scrollType = scrollType;
invalidate();
}
/**
* 设置滚动速度
*
* @param speedType 滚动速度
*/
public void setSpeedType(int speedType) {
switch (speedType) {
case SPEED_SLOW:
verticalSpeed = 0.4f;
horizontalSpeed = 2f;
break;
case SPEED_NORMAL:
verticalSpeed = 0.8f;
horizontalSpeed = 4f;
break;
case SPEED_FAST:
verticalSpeed = 1.2f;
horizontalSpeed = 6f;
break;
case SPEED_EXPRESS:
verticalSpeed = 1.6f;
horizontalSpeed = 8f;
break;
default:
break;
}
invalidate();
}
/**
* 设置行高
*
* @param lineSpace 行高
*/
public void setLineSpace(float lineSpace) {
this.lineSpace = lineSpace;
invalidate();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
String text = getText().toString();
if (!TextUtils.isEmpty(text) && scrollType == SCROLL_BT) {
//由下往上滚动需要测量高度
setTextList(widthMeasureSpec, text);
}
}
/**
* 根据TextView宽度和字体大小,计算显示的行数。
*
* @param widthMeasureSpec 测量模式
* @param text             文本
*/
private void setTextList(int widthMeasureSpec, String text) {
textList.clear();
float width = MeasureSpec.getSize(widthMeasureSpec);
float length = 0;
for (int i = 0; i < text.length(); i++) {
if (length <= width) {
textBuilder.append(text.charAt(i));
length += paint.measureText(text.substring(i, i + 1));
if (i == text.length() - 1) {
if (length <= width) {
textList.add(textBuilder.toString());
} else {
if (textBuilder.toString().length() == 1) {
//每行最多显示一个字
textList.add(text.substring(text.length() - 1));
} else {
//去掉最后一个字,否则最后一个字显示不完整
textList.add(textBuilder.toString().substring(0, textBuilder.toString().length() - 1));
//最后一个字单独一行
textList.add(text.substring(text.length() - 1));
}
}
}
} else {
if (textBuilder.toString().length() == 1) {
//每行最多显示一个字
textList.add(textBuilder.toString());
textBuilder.delete(0, textBuilder.length());
i--;
length = 0;
} else {
//去掉最后一个字,否则最后一个字显示不完整
textList.add(textBuilder.toString().substring(0, textBuilder.toString().length() - 1));
textBuilder.delete(0, textBuilder.length() - 1);
i--;
length = paint.measureText(text.substring(i, i + 1));
}
}
}
//清空textBuilder
textBuilder.delete(0, textBuilder.length());
}
@Override
public void onDraw(Canvas canvas) {
String text = getText().toString();
if (TextUtils.isEmpty(text)) {
super.onDraw(canvas);
return;
}
switch (scrollType) {
case SCROLL_NO:
super.onDraw(canvas);
break;
case SCROLL_BT:
//从下往上滚动,首次不显示文字,后续从下往上显示
float textSize = paint.getTextSize();
for (int i = 0; i < textList.size(); i++) {
float currentY = getHeight() + (i + 1) * textSize - scrollStep;
if (i > 0) {
currentY = currentY + i * lineSpace;
}
canvas.drawText(textList.get(i), 0, currentY, paint);
}
scrollStep = scrollStep + verticalSpeed;
if (scrollStep >= getHeight() + textList.size() * textSize + (textList.size() - 1) * lineSpace) {
scrollStep = 0;
}
invalidate();
break;
case SCROLL_RL:
//从右向左滚动,首次不显示文字,后续每次往左偏移speed像素
paint.getTextBounds(text, 0, text.length(), rect);
int textWidth = rect.width();
int textHeight = rect.height();
int viewWidth = getWidth();
float currentX = viewWidth - scrollStep;
canvas.drawText(text, currentX, textHeight, paint);
scrollStep = scrollStep + horizontalSpeed;
if (scrollStep >= viewWidth + textWidth) {
scrollStep = 0;
}
invalidate();
break;
default:
break;
}
}
}

attrs.xml文件源码:

<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="MarqueeView">
<attr name="scrollType">
<enum name="no" value="1" />
<enum name="vertical" value="2" />
<enum name="horizontal" value="3" />
</attr>
<attr name="speedType">
<enum name="slow" value="4" />
<enum name="normal" value="5" />
<enum name="fast" value="6" />
<enum name="express" value="7" />
</attr>
<attr name="textColor" format="color" />
<!--行高,只对垂直滚动有效-->
<attr name="lineSpace" format="integer" />
</declare-styleable>
</resources>

这里自定义了3个属性供大家使用,可以XML中配置,也可以在代码中设置。 MarqueeView中已对每个方法做了注释,此处不再描述。

scrollType:滚动类型(不滚动、垂直滚动、水平滚动)
speedType:滚动速度类型(慢速、中速、快速、特快)
textColor:文本颜色
lineSpace:行高(仅对垂直滚动有效)
MainActivity源码:
package com.otess.marquee;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}

可以看到MainActivity中,都是自动生成的一些代码,因为demo中不需要动态设置跑马灯效果。

activity_main.xml源码:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<com.otess.marquee.MarqueeView
android:id="@+id/mv_horizontal"
android:layout_width="match_parent"
android:layout_height="100dp"
android:background="#316331"
android:text="水平滚动文本"
app:layout_constraintTop_toTopOf="parent"
app:scrollType="horizontal"
app:speedType="normal"
app:textColor="#fff" />
<com.otess.marquee.MarqueeView
android:layout_width="match_parent"
android:layout_height="100dp"
android:layout_marginTop="30dp"
android:background="#316331"
android:text="垂直滚动文本"
app:layout_constraintTop_toBottomOf="@id/mv_horizontal"
app:scrollType="vertical"
app:speedType="normal"
app:textColor="#fff" />
</android.support.constraint.ConstraintLayout>

这里为了测试,简单的配置了些样式,大家请根据实际需求自行调整。

如有疑问,欢迎留言!

人已赞赏
Android文章

Android指定文件缓存路径

2020-3-8 3:22:29

Android文章

Android Studio 无法通过usb识别手机

2020-3-8 5:28:47

个人中心
购物车
优惠劵
今日签到
有新私信 私信列表
有新消息 消息中心
搜索