Question

安卓开发如何在EditText左边添加行数

类似eclipse的行数显示

试过getHeight()除以getLineHeight()再给旁边的textView setText，但是行数多了就刷新不过来了，怎么办？

Answer 1

也可以重写EditText

package com.mycompany.myedit;
import android.content.*;
import android.widget.*;
import android.graphics.*;
import android.util.*;
import android.text.*;
import android.view.*;

public class MyEditText extends EditText
{
private Paint line;
public MyEditText(Context context,AttributeSet As){
super(context,As);
setFocusable(true);
line=new Paint();
line.setColor(Color.RED);
line.setStrokeWidth(2);
setPadding(95,0,0,0);
setGravity(Gravity.TOP);
}

@Override
protected void onDraw(final Canvas canvas)
{
// TODO: Implement this metho

if(getText().toString().length()!=0){
float y=0;
Paint p=new Paint();
p.setColor(Color.GRAY);
p.setTextSize(40);
for(int l=0;l<getLineCount();l++){
y=((l+1)*getLineHeight())-(getLineHeight()/4);
canvas.drawText(String.valueOf(l+1),0,y,p);
canvas.save();
}
}
int k=getLineHeight();
int i=getLineCount();
canvas.drawLine(90,0,90,getHeight()+(i*k),line);
int y=(getLayout().getLineForOffset(getSelectionStart())+1)*k;
canvas.drawLine(0,y,getWidth(),y,line);
canvas.save();
canvas.restore();
super.onDraw(canvas);
}
}

参考链接：http://tieba.baidu.com/p/3948623080

追问

隔了整整一年了还有人回答，实在是感谢！

Answer 2

tv = (TextView)this.findViewById(R.id.tv);

et = (EditText)this.findViewById(R.id.et);

tv.setText(" 1");

et.addTextChangedListener(new TextWatcher() {

@Override

public void onTextChanged(CharSequence s, int start, int before, int count) {

if(s.length()!=0){

String str = "";

for(int i = 0 ; i<et.getLineCount()+1 ; i++){

str = str + " "+(i+1)+"\n";

}

tv.setText(str);

}

}

@Override

public void beforeTextChanged(CharSequence s, int start, int count,

int after) {

}

@Override

public void afterTextChanged(Editable s) {

}

});

layout布局：
<LinearLayout

android:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="horizontal"

>

<TextView

android:id="@+id/tv"

android:layout_width="50px"

android:layout_height="wrap_content"

android:textSize="12sp"

android:layout_marginTop="20px"

android:gravity="center|right"

android:lineSpacingExtra="2sp"

/>

<EditText

android:id="@+id/et"

android:layout_width="400px"

android:layout_height="wrap_content"

android:textSize="12sp"

android:layout_marginTop="20px"

android:layout_marginLeft="10px"

android:gravity="center|left"

android:lineSpacingExtra="2sp"

/>

</LinearLayout>