android自定义View实现图片上传进度显示（仿手机QQ上传效果）

首先看下我们想要实现的效果如下图（qq聊天中发送图片时的效果）：



再看一下我实现的效果：



1、效果已经看见了，下面我们来实现它。首先我创建一个android工程ProgressImageView。然后我们重写ImageView控件，创建ProcessImageView类代码如下：

[cpp] view
plaincopy

package com.example.processimageview;



import android.annotation.SuppressLint;

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.Rect;

import android.util.AttributeSet;

import android.view.ViewGroup.LayoutParams;

import android.widget.ImageView;



public class ProcessImageView extends ImageView {



private Paint mPaint;// 画笔

int width = 0;

int height = 0;

Context context = null;

int progress = 0;



public ProcessImageView(Context context) {

super(context);

// TODO Auto-generated constructor stub

}



public ProcessImageView(Context context, AttributeSet attrs) {

this(context, attrs, 0);

}



public ProcessImageView(Context context, AttributeSet attrs,

int defStyleAttr) {

super(context, attrs, defStyleAttr);

this.context = context;

mPaint = new Paint();

}



@SuppressLint("DrawAllocation")

@Override

protected void onDraw(Canvas canvas) {

super.onDraw(canvas);

mPaint.setAntiAlias(true); // 消除锯齿

mPaint.setStyle(Paint.Style.FILL);





mPaint.setColor(Color.parseColor("#70000000"));// 半透明

canvas.drawRect(0, 0, getWidth(), getHeight()- getHeight() * progress

/ 100, mPaint);



mPaint.setColor(Color.parseColor("#00000000"));// 全透明

canvas.drawRect(0, getHeight() - getHeight() * progress / 100,

getWidth(), getHeight(), mPaint);



mPaint.setTextSize(30);

mPaint.setColor(Color.parseColor("#FFFFFF"));

mPaint.setStrokeWidth(2);

Rect rect = new Rect();

mPaint.getTextBounds("100%", 0, "100%".length(), rect);// 确定文字的宽度

canvas.drawText(progress + "%", getWidth() / 2 - rect.width() / 2,

getHeight() / 2, mPaint);



}



public void setProgress(int progress) {

this.progress = progress;

postInvalidate();

};



}

2、将ProcessImageView控件加入activity_layout.xml布局文件中,代码如下;

[cpp] view
plaincopy

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

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

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"

tools:context="com.example.processimageview.MainActivity" >



<com.example.processimageview.ProcessImageView

android:id="@+id/image"

android:layout_centerInParent = "true"

android:layout_width="200dp"

android:layout_height="300dp"

android:contentDescription="This is a ProcessImage"

android:src="@drawable/image" />



</RelativeLayout>

3、最后一步，显示效果(是不是很激动

)，在MainActivity类加入显示进度条的ImageView，代码如下：

[java] view
plaincopy

package com.example.processimageview;



import android.app.Activity;

import android.os.Bundle;

import android.os.Handler;

import android.os.Message;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.view.ViewGroup.LayoutParams;

import android.widget.Toast;



public class MainActivity extends Activity {



ProcessImageView processImageView =null;

private final int SUCCESS=0;

int progress=0;



Handler handler=new Handler(){

@Override

public void handleMessage(Message msg) {

super.handleMessage(msg);

switch (msg.what) {

case SUCCESS:

Toast.makeText(MainActivity.this, "图片上传完成", Toast.LENGTH_SHORT).show();

processImageView.setVisibility(View.GONE);

break;

}

}

};



@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);



processImageView=(ProcessImageView) findViewById(R.id.image);

//模拟图片上传进度

new Thread(new Runnable() {

@Override

public void run() {

while (true){

if(progress==100){//图片上传完成

handler.sendEmptyMessage(SUCCESS);

return;

}

progress++;

processImageView.setProgress(progress);

try{

Thread.sleep(200); //暂停0.2秒

} catch (InterruptedException e){

e.printStackTrace();

}

}

}

}).start();

}



@Override

public boolean onCreateOptionsMenu(Menu menu) {

// Inflate the menu; this adds items to the action bar if it is present.

getMenuInflater().inflate(R.menu.main, menu);

return true;

}



@Override

public boolean onOptionsItemSelected(MenuItem item) {

// Handle action bar item clicks here. The action bar will

// automatically handle clicks on the Home/Up button, so long

// as you specify a parent activity in AndroidManifest.xml.

int id = item.getItemId();

if (id == R.id.action_settings) {

return true;

}

return super.onOptionsItemSelected(item);

}

}

4、编译运行，大功告成。