就是大家叫的跑马灯效果。对4.0以上，简单地在TextView里面加上4句就可以了：

android:ellipsize="marquee"

android:focusable="true"

android:focusableInTouchMode="true"

android:singleLine="true"

但是如果这个TextView属于ListView的子View，并且list item设置了android:descendantFocusability="blocksDescendants"等比较复杂的情况时，上述方法不行。必须在自定义View上drawText，在http://gundumw100.iteye.com/blog/965366的基础上，整理了些干货：

FloatableTextView.java:

package com.example.floatabletextview;

import android.content.Context;

import android.graphics.Canvas;

import android.os.Parcel;

import android.os.Parcelable;

import android.util.AttributeSet;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.TextView;

/**

* 单行TextView，容纳不下就左移

*/

public class FloatableTextView extends TextView implements OnClickListener {

public boolean mIsFloating = false; //是否开始滚动

private float mSpeed = 0.5f;

private float mStep = 0f;

private String mStr = ""; //文本内容

private float mTextLength = 0f; //文本长度

private float mViewWidth = 0f;

private float mY = 0f; //文字的纵坐标

public FloatableTextView(Context context) {

super(context);

initView();

}

public FloatableTextView(Context context, AttributeSet attrs) {

super(context, attrs);

initView();

}

public FloatableTextView(Context context, AttributeSet attrs, int defStyle) {

super(context, attrs, defStyle);

initView();

}

private void initView() {

setOnClickListener(this);

}

public void init(String str, float speed, float width) {

setText(str);

mSpeed = speed;

mStr = getText().toString();

mTextLength = getPaint().measureText(mStr);

mViewWidth = width;

mStep = mTextLength + mViewWidth;

mY = getTextSize() + getPaddingTop();

getPaint().setColor(0xff0000ff);

}

@Override

public void onClick(View v) {

if (mIsFloating)

stopFloating();

else

startFloating();

}

@Override

public void onDraw(Canvas canvas) {

canvas.drawText(mStr, 0, mStr.length(), mViewWidth + mTextLength - mStep, mY, getPaint());

if (!mIsFloating)

return;

mStep += mSpeed;

if (mStep > mViewWidth + mTextLength * 2)

mStep = mTextLength;

invalidate();

}

@Override

public void onRestoreInstanceState(Parcelable state) {

if (!(state instanceof SavedState)) {

super.onRestoreInstanceState(state);

return;

}

SavedState savedState = (SavedState) state;

super.onRestoreInstanceState(savedState.getSuperState());

mStep = savedState.mStep;

mIsFloating = savedState.mIsFloating;

}

@Override

public Parcelable onSaveInstanceState() {

Parcelable superState = super.onSaveInstanceState();

SavedState savedState = new SavedState(superState);

savedState.mStep = mStep;

savedState.mIsFloating = mIsFloating;

return savedState;

}

public void setSpeed(float speed) {

mSpeed = speed;

}

public void startFloating() {

mIsFloating = mTextLength > mViewWidth;

// mIsFloating = true;

invalidate();

}

public void stopFloating() {

mIsFloating = false;

invalidate();

}

public static class SavedState extends BaseSavedState {

public static final Parcelable.Creator CREATOR = new Parcelable.Creator() {

@Override

public SavedState createFromParcel(Parcel in) {

return new SavedState(in);

}

public SavedState[] newArray(int size) {

return new SavedState[size];

}

};

public boolean mIsFloating = false;

public float mStep = 0.0f;

private SavedState(Parcel in) {

super(in);

boolean[] b = new boolean[1];

in.readBooleanArray(b);

mIsFloating = b[0];

mStep = in.readFloat();

}

SavedState(Parcelable superState) {

super(superState);

}

@Override

public void writeToParcel(Parcel out, int flags) {

super.writeToParcel(out, flags);

out.writeBooleanArray(new boolean[] {

mIsFloating

});

out.writeFloat(mStep);

}

}

}

MainActivity.java:

package com.example.floatabletextview;

import android.app.ListActivity;

import android.os.Bundle;

import android.view.View;

import android.view.ViewGroup;

import android.widget.BaseAdapter;

import com.example.zlistmarquee.R;

public class MainActivity extends ListActivity {

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

setListAdapter(new MyAdapter());

}

class MyAdapter extends BaseAdapter {

@Override

public int getCount() {

return 9;

}

@Override

public Object getItem(int position) {

return null;

}

@Override

public long getItemId(int position) {

return 0;

}

@Override

public View getView(int position, View convertView, ViewGroup parent) {

View v = getLayoutInflater().inflate(R.layout.list_item, null);

FloatableTextView floatableTextView = (FloatableTextView) v.findViewById(R.id.floatable_text_view);

floatableTextView.init("速度 岁的 电话 离开 的灯光 撒旦斯蒂芬 无污染", 0.9f, 100);

floatableTextView.startFloating();

return v;

}

}

}

list_item.xml:

android:layout_width="match_parent"

android:layout_height="30dp"

android:orientation="horizontal" >

android:layout_width="90dp"

android:layout_height="fill_parent"

android:background="@android:color/holo_green_dark" >

android:id="@+id/floatable_text_view"

android:layout_width="80dp"

android:layout_height="30dp"

android:background="@android:color/holo_blue_bright" />

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:background="@android:color/holo_green_light" >

activity_main.xml:

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent" >

android:id="@android:id/list"

android:layout_width="fill_parent"

android:layout_height="wrap_content" >