Android实现TextView文字水平滚动效果实现详解编程语言

第一步：编写MarqueeText.java类，继承自TextView

import android.annotation.SuppressLint;   
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 MarqueeText extends TextView {   
     /** 是否停止滚动 */   
    private boolean mStopMarquee;   
    private String mText;   
    private float mCoordinateX;   
    private float mTextWidth;   
   
   
    public MarqueeText(Context context, AttributeSet attrs) {   
        super(context, attrs);   
    }   
   
   
    public void setText(String text) {   
        this.mText = text;   
        mTextWidth = getPaint().measureText(mText);   
        if (mHandler.hasMessages(0))   
            mHandler.removeMessages(0);   
        mHandler.sendEmptyMessageDelayed(0, 2000);   
    }   
   
   
    @SuppressLint("NewApi")   
    @Override   
    protected void onAttachedToWindow() {   
        mStopMarquee = false;   
        if (!(mText == null || mText.isEmpty()))   
            mHandler.sendEmptyMessageDelayed(0, 2000);   
        super.onAttachedToWindow();   
    }   
   
   
    @Override   
    protected void onDetachedFromWindow() {   
        mStopMarquee = true;   
        if (mHandler.hasMessages(0))   
            mHandler.removeMessages(0);   
        super.onDetachedFromWindow();   
    }   
   
   
    @SuppressLint("NewApi")   
    @Override   
    protected void onDraw(Canvas canvas) {   
        super.onDraw(canvas);   
        if (!(mText == null || mText.isEmpty()))   
            canvas.drawText(mText, mCoordinateX, 30, getPaint());   
    }   
   
   
    @SuppressLint("HandlerLeak")   
    private Handler mHandler = new Handler() {   
        @Override   
        public void handleMessage(Message msg) {   
            switch (msg.what) {   
            case 0:   
                if (Math.abs(mCoordinateX) > (mTextWidth + 5)) {   
                    mCoordinateX = 0;   
                    invalidate();   
                    if (!mStopMarquee) {   
                        sendEmptyMessageDelayed(0,500);   
                    }   
                } else {   
                    mCoordinateX -= 1;   
                    invalidate();   
                    if (!mStopMarquee) {   
                        sendEmptyMessageDelayed(0, 30);   
                    }   
                }   
                break;   
            }   
            super.handleMessage(msg);   
        }   
    };   
}  

第二步：编写布局文件main.xml

第三步：编写SYIT_Index.java继承自Activity类

import java.io.IOException;   
import cn.superyouth.www.itools.MarqueeText;   
import android.annotation.SuppressLint;   
import android.app.Activity;   
import android.content.ComponentName;   
import android.content.Intent;   
import android.graphics.Color;   
import android.os.AsyncTask;   
import android.os.Bundle;   
import android.os.Handler;   
import android.os.Message;   
import android.text.method.ScrollingMovementMethod;   
import android.view.View;   
import android.view.View.OnClickListener;   
import android.widget.AdapterView;   
import android.widget.GridView;   
import android.widget.TextView;   
import android.widget.Toast;   
import android.widget.AdapterView.OnItemClickListener;   
   
   
public class SYIT_Index extends Activity {   
    MarqueeText autoScrollTextView;   
   
   
    public void onCreate(Bundle savedInstanceState) {   
        super.onCreate(savedInstanceState);   
        setContentView(R.layout.main);   
   
   
        autoScrollTextView = (MarqueeText) findViewById(R.id.textMsg);   
        autoScrollTextView.setTextSize(30);   
           
        autoScrollTextView.setTextColor(Color.BLUE);   
        autoScrollTextView.setText("暂无任何预警信息!");   
        // 点击预警提示信息   
        autoScrollTextView.setOnClickListener(new OnClickListener() {   
            public void onClick(View arg0) {   
                // 进入预警信息页面   
                Intent intent = new Intent(SYIT_Index.this, SYIT_Warning.class);   
                startActivity(intent);   
            }   
        });   
     }   
}