The app I'm building have root-access to Android. I wish to show Logcat log information in one of the TextView so it can show up on the screen while i'm debugging.
Can someone give me some ideas which library/function i can call to access those log?
Thanks
Dawid Czerwinski
Here's a blogpost that does exactly what you need it to do. It has a complete code example on how to display the contents of the Logcat log. Here's the code:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
class ReadLogDemo extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
try {
Process process = Runtime.getRuntime().exec("logcat -d");
BufferedReader bufferedReader = new BufferedReader(
new InputStreamReader(process.getInputStream()));
StringBuilder log=new StringBuilder();
String line = "";
while ((line = bufferedReader.readLine()) != null) {
log.append(line);
}
TextView tv = (TextView)findViewById(R.id.textView1);
tv.setText(log.toString());
} catch (IOException e) {
// Handle Exception
}
}
}
Just to clarify, this is not my answer, here is the original
Well, there is a solution to log anything you want to screen using this lib. It didn't worked for me, so I develop my own solution you can find an example of it here. It's really simple, just add a class OnScreenLog to your project
package br.com.ideiageni.onscreenlogSample;
import android.app.Activity;
import android.graphics.Color;
import android.os.Handler;
import android.view.MotionEvent;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.TextView;
/**
* Created by ariel on 07/07/2016.
*/
public class OnScreenLog {
private static int timeoutTime = 1000;
private static TextView tvLog;
private static int logCount = 0;
private static int logCountMax = 30;
private static String[] logs = new String[logCountMax];
private static int cntClicks = 0;
private static boolean visibility = false;
private static Activity activity;
private int maxClicks = 5;
public OnScreenLog(){}
public OnScreenLog(Activity activity, int ViewID){
OnScreenLog.activity = activity;
tvLog = new TextView(activity.getApplicationContext());
maintainLog("Log is working");
tvLog.setLayoutParams(new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT,
RelativeLayout.LayoutParams.WRAP_CONTENT));
tvLog.setTextColor(Color.BLACK);
tvLog.setBackgroundColor(Color.LTGRAY);
tvLog.setAlpha((float) 0.4);
View v = null;
LinearLayout linearLayout;
RelativeLayout relativeLayout;
try {
linearLayout = (LinearLayout) activity.findViewById(ViewID);
} catch (ClassCastException e) {linearLayout = null;};
try {
relativeLayout = (RelativeLayout) activity.findViewById(ViewID);
} catch (ClassCastException e) {relativeLayout = null;};
if(linearLayout != null) {
linearLayout.addView(tvLog);
v = linearLayout;
} else if(relativeLayout != null) {
relativeLayout.addView(tvLog);
v = relativeLayout;
}
if(v != null) {
v.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
cntClicks++;
timerHandler.removeCallbacks(rTimeout);
timerHandler.postDelayed(rTimeout, timeoutTime);
if (cntClicks > maxClicks-1) {
setLogVisible(!visibility);
timerHandler.removeCallbacks(rTimeout);
cntClicks = 0;
}
break;
}
return false;
}
});
}
}
public void log (String text){
String logText = text;
maintainLog(logText);
}
public void log (int text){
String logText = String.valueOf(text);
maintainLog(logText);
}
public void log (int[] text){
StringBuilder builder = new StringBuilder();
for (int i : text) {
builder.append(i);
builder.append("-");
}
String logText = builder.toString();
maintainLog(logText);
}
public void log (byte[] text){
StringBuilder builder = new StringBuilder();
for (int i : text) {
builder.append(i);
builder.append("-");
}
String logText = builder.toString();
maintainLog(logText);
}
private void maintainLog(String newText){
String logText = "";
if(logCount<logCountMax) logCount++;
for(int i=logCount-1; i>0; i--){
logs[i] = logs[i-1];
}
logs[0] = newText;
for(int i=0; i<logCount; i++){
if(i<logCount-1) logText+=logs[i]+System.getProperty("line.separator");
else logText+=logs[i];
}
tvLog.setText(logText);
}
public void clearLog(){
tvLog.setText("");
}
public void setLogVisible(boolean visibility){
if(visibility) tvLog.setVisibility(View.VISIBLE);
else tvLog.setVisibility(View.INVISIBLE);
OnScreenLog.visibility = visibility;
}
public static int getLogCountMax() {
return logCountMax;
}
public static void setLogCountMax(int logCountMax) {
OnScreenLog.logCountMax = logCountMax;
logs = new String[logCountMax];
}
public int getMaxClicks() {
return maxClicks;
}
public void setMaxClicks(int maxClicks) {
this.maxClicks = maxClicks;
}
Handler timerHandler = new Handler();
Runnable rTimeout = new Runnable() {
@Override
public void run() {
cntClicks = 0;
}
};
}
then, for instance:
public class Activity1 extends AppCompatActivity {
private OnScreenLog log;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_1);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
log = new OnScreenLog(this, R.id.content_1);
log.log("Started log on Activity 1");
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent(getApplicationContext(), Activity2.class);
startActivity(intent);
log.log("Starting Activity 2");
Snackbar.make(view, "Starting Activity 2", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
}
Where R.id.content_1 is the name of the main LinearLayout or RelativeLayout of your activity.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
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:id="@+id/content_1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="br.com.ideiageni.onscreenlogSample.Activity1"
tools:showIn="@layout/activity_1">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Activity 1!" />
</RelativeLayout>
Work not finished yet but can be used for anyone in need. Missing some directions on how to use. Suggestions are welcome.
If you want to clean up the output of the above answer a little bit to a certain topic then here is one solution:
**The colon may not work depending on how your log is formatted**
while ((line = bufferedReader.readLine()) != null) {
CharSequence cs = "Mqtt:"; //topic string (the colon helps cut out false positives)
if (line.contains(cs)) {
log.append(line.substring(line.indexOf("Mqtt:"),line.length())); // Cuts out the junk at the beginning of the log
log.append("\n"); // makes log print line by line like normal
}
}
Thanks @Dawid for the great link to a good answer!
来源：https://stackoverflow.com/questions/25351286/android-display-logcat-in-textview