scene

Progress bar effect

Note:

Blog:
https://blog.csdn.net/badao_liumang_qizhi
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Realization

Change the layout to relative, then add a ProgressBar and add the id attribute.

Then pass

 android:max="100"

Set progress bar maximum

adopt

android:layout_alignParentBottom="true"
android:layout_marginBottom="50dp"

Set its position at the bottom and set the outer margin

For the style of the progress bar, refer to the following

The progress bar style used here is

style="?android:attr/progressBarStyleHorizontal"

Complete xml sample code

<?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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ProgressBarActivity">

    <ProgressBar
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        style="?android:attr/progressBarStyleHorizontal"
        android:max="100"
        android:layout_alignParentBottom="true"
        android:layout_marginBottom="50dp"
        android:id="@+id/progressBar"

        />

</RelativeLayout>

Then come to Activity

The simple process to implement the progress bar is as follows

First, declare the progress bar object, progress value and Handler object in the Activity.

About the Hnadler object, because Android does not support updating UI controls in the main thread, it provides a Handler object.

First, get the progress bar object through id, and then instantiate the Handler. You need to override its handleMessage method

In the handleMessage method, the identification of msg is used to determine whether the loading of progress bar is completed.

Then a new thread needs to be opened to add progress value to the progress bar randomly in the thread, and then judge whether it reaches 100, and then report different progress and identification variables.

Full sample code

package com.badao.relativelayouttest;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.ProgressBar;
import android.widget.Toast;

import java.util.prefs.PreferenceChangeEvent;

public class ProgressBarActivity extends AppCompatActivity {

    private ProgressBar progressBar;
    private int mProgress = 0;
    private  Handler mHandler;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_progress_bar);

        //Get progress bar control
        progressBar = (ProgressBar) findViewById(R.id.progressBar);
        //Android Update in main thread is not supported UI Component so provides Handler object
        mHandler = new Handler(){
            //Via message code msg Differentiate whether loading is complete
            @Override
            public void handleMessage(@NonNull Message msg) {
                if(msg.what ==0x111)
                {
                    //Assign value to progress bar
                    progressBar.setProgress(mProgress);
                }else
                {
                    Toast.makeText(ProgressBarActivity.this,"Load complete",Toast.LENGTH_SHORT).show();
                    progressBar.setVisibility(View.GONE);
                }
            }
        };

        //New thread
        new Thread(new Runnable() {
            @Override
            public void run() {
                while (true)
                {
                    //Progress of specific implementation method, return to progress
                    mProgress = doWork();
                    //Define an ID to identify whether the progress bar has been loaded
                    Message message = new Message();
                    if(mProgress <100)
                    {
                        //Indicates that the progress has not been loaded to 100, report the progress to the progress bar
                        message.what = 0x111;
                        mHandler.sendMessage(message);
                    }else
                    {
                        //Indicates that the loading is completed, and the Handler Send message and jump out of loop
                        message.what =0x110;
                        mHandler.sendMessage(message);
                        break;
                    }
                }
            }
            //How to execute and return progress
            private int doWork()
            {
                //Progress bar random plus progress
                mProgress +=Math.random()*10;
                try {
                    //Process sleep 0.5 second
                    Thread.sleep(500);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                return mProgress;
            }
        }).start(); //Startup process
    }
}