Android開發：TextView真正可控、不需要焦點的水平滾動--這才是真正的跑馬燈

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網上的TextView做跑馬燈，大多都是要用到焦點，而且字數要超出捲動區域寬度才能實現滾動，使用起來十分不方便。

這裡實現一種真正可控的滾動

(1)不需要焦點

(2)任意字數

(3)滾動從捲動區域右邊出來，在左邊消失，再從右邊出來。

上代碼

1、布局檔案

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="${relativePackage}.${activityClass}" >   <Button        android:id="@+id/btn1"       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:text="改變滾動內容1"/>      <Button        android:id="@+id/btn2"       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:layout_toRightOf="@id/btn1"       android:text="改變滾動內容2"/>       <Button        android:id="@+id/btn3"       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:layout_toRightOf="@id/btn2"       android:text="退出程式"/>        <com.using.margindemo.MarqueeTextView        android:id="@+id/tvScroll"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:textSize="40dp" >    </com.using.margindemo.MarqueeTextView></RelativeLayout>

 

2、滾動控制項

package com.using.margindemo;import android.content.Context;import android.graphics.Canvas;import android.os.Handler;import android.os.Message;import android.util.AttributeSet;import android.widget.TextView;public class MarqueeTextView extends TextView {    /** 是否停止滾動 */    private boolean mStopMarquee;    private String mText;//常值內容    private float mCoordinateX = 1280;//當前滾動位置    private float mTextWidth;//文本寬度    private int mScrollWidth = 1280;//捲動區域寬度    private int speed = 1;//捲動速度    public float getCurrentPosition() {        return mCoordinateX;    }    public void setCurrentPosition(float mCoordinateX) {        this.mCoordinateX = mCoordinateX;    }    public int getScrollWidth() {        return mScrollWidth;    }    public void setScrollWidth(int mScrollWidth) {        this.mScrollWidth = mScrollWidth;    }    public int getSpeed() {        return speed;    }    public void setSpeed(int speed) {        this.speed = speed;    }    public MarqueeTextView(Context context, AttributeSet attrs) {        super(context, attrs);    }    public void setText(String text) {        this.mText = text;        mTextWidth = getPaint().measureText(mText);        //mTextWidth = 1280;        if (mHandler.hasMessages(0))            mHandler.removeMessages(0);        mHandler.sendEmptyMessageDelayed(0, 10);    }    @Override    protected void onAttachedToWindow() {        mStopMarquee = false;        if (!isEmpty(mText))            mHandler.sendEmptyMessageDelayed(0, 2000);        super.onAttachedToWindow();    }    public static boolean isEmpty(String str) {        return str == null || str.length() == 0;    }    @Override    protected void onDetachedFromWindow() {        mStopMarquee = true;        if (mHandler.hasMessages(0))            mHandler.removeMessages(0);        super.onDetachedFromWindow();    }    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        if (!isEmpty(mText))            canvas.drawText(mText, mCoordinateX, 150, getPaint());    }    private Handler mHandler = new Handler() {        @Override        public void handleMessage(Message msg) {            switch (msg.what) {            case 0:                                    if (mCoordinateX < (-mTextWidth)) {//文字滾動完了，從捲動區域的右邊出來                    mCoordinateX = mScrollWidth;                    invalidate();                    if (!mStopMarquee) {                    sendEmptyMessageDelayed(0, 500);                    }                } else {                    mCoordinateX -= speed;                    invalidate();                    if (!mStopMarquee) {                        sendEmptyMessageDelayed(0, 30);                    }                }                break;            }            super.handleMessage(msg);        }    };}

 

3、

package com.using.margindemo;import android.app.ActionBar;import android.app.Activity;import android.content.res.Configuration;import android.os.Bundle;import android.util.Log;import android.view.View;import android.view.View.OnClickListener;import android.view.ViewGroup.MarginLayoutParams;import android.view.Window;import android.view.WindowManager;import android.widget.Button;import android.widget.ImageView;import android.widget.RelativeLayout;public class MainActivity extends Activity {    private ImageView image;    private MarqueeTextView marqueeTextView;    private Button button1;    private Button button2;    private Button button3;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        this.requestWindowFeature(Window.FEATURE_NO_TITLE);//隱藏標題列        setContentView(R.layout.activity_main);                        marqueeTextView = (MarqueeTextView)findViewById(R.id.tvScroll);                        MarginLayoutParams margin1 = new MarginLayoutParams(                marqueeTextView.getLayoutParams());        margin1.setMargins(100, 200, 0, 0);//設定捲動區域位置：在左邊距400像素，頂邊距10像素的位置        RelativeLayout.LayoutParams layoutParams1 = new RelativeLayout.LayoutParams(margin1);        layoutParams1.height = 240;//設捲動區域高度        layoutParams1.width = 1000; //設定捲動區域寬度        marqueeTextView.setLayoutParams(layoutParams1);                        marqueeTextView.setScrollWidth(1000);        marqueeTextView.setCurrentPosition(100 + 1000);//設定滾動資訊從捲動區域的右邊出來        marqueeTextView.setSpeed(2);        marqueeTextView.setText("這才是真正的跑馬燈效果！");        button1 = (Button)findViewById(R.id.btn1);        button2 = (Button)findViewById(R.id.btn2);        button3 = (Button)findViewById(R.id.btn3);                button1.setOnClickListener(new OnClickListener() {                        @Override            public void onClick(View v) {                marqueeTextView.setText("這才是真正的跑馬燈效果！");                            }        });                 button2.setOnClickListener(new OnClickListener() {                        @Override            public void onClick(View v) {                marqueeTextView.setText("溫馨提示：挂號或繳費後，請到休息區等候，我們會儘快為您服務，請留意螢幕叫號資訊，謝謝！");                            }        });         button3.setOnClickListener(new OnClickListener() {                         @Override             public void onClick(View v) {                 finish();             }         });    }}

 

 

Demo下載

 

Android開發：TextView真正可控、不需要焦點的水平滾動--這才是真正的跑馬燈