Android：ANR、线程间通讯、Handler、Message
场景：点击按钮1进行下载，显示进度条进度变化，10秒后下载完成，进度条消失；点击按钮2完成更新，出现转动进度条，5秒后更新完毕进度条消失。
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public
class
MainActivity
extends
Activity
implements
OnClickListener
{
TextView textView =
null
;
private
ProgressBar mProgress_yuan;
private
ProgressBar mProgress_jindu;
private
final
int
MSG_WHAT_DOWNLOAD =
1
;
private
final
int
MSG_WHAT_UPDATE =
2
;
private
final
int
MSG_WHAT_PROGRESS =
3
;
private
Handler mHandler =
new
Handler()
// Handler运行于main线程,在main线程接收消息
{
@Override
public
void
handleMessage(Message msg)
// 重写handleMessage方法
{
switch
(msg.what)
{
case
MSG_WHAT_DOWNLOAD:
Data data = (Data) msg.obj;
textView.setText(data.toString());
mProgress_jindu.setVisibility(View.GONE);
// 下载完成后，进度条消失
break
;
case
MSG_WHAT_UPDATE:
String str = (String) msg.obj;
textView.setText(str);
mProgress_yuan.setVisibility(View.GONE);
// 更新完毕后，圆形进度框消失
break
;
case
MSG_WHAT_PROGRESS:
int
arg = msg.arg1;
mProgress_jindu.setProgress(arg);
// 每次接收消息，更新进度条
break
;
default
:
break
;
}
}
};
@Override
protected
void
onCreate(Bundle savedInstanceState)
{
super
.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.button1).setOnClickListener(
this
);
findViewById(R.id.button2).setOnClickListener(
this
);
textView = (TextView) findViewById(R.id.textView1);
mProgress_yuan = (ProgressBar) findViewById(R.id.progressBar1);
mProgress_jindu = (ProgressBar) findViewById(R.id.progressBar2);
}
@Override
public
boolean
onCreateOptionsMenu(Menu menu)
{
getMenuInflater().inflate(R.menu.activity_main, menu);
return
true
;
}
@Override
public
void
onClick(View v)
{
switch
(v.getId())
{
case
R.id.button1:
btn1Click();
break
;
case
R.id.button2:
btn2Click();
break
;
default
:
break
;
}
}
private
void
btn1Click()
// 点击下载，10秒后下载完成,进度条消失
{
mProgress_jindu.setVisibility(View.VISIBLE);
// 点击时进度条显示（xml设置默认隐藏）
new
Thread()
{
@Override
public
void
run()
{
Message message =
new
Message();
message.what = MSG_WHAT_DOWNLOAD;
// 设置标识
message.obj = download();
// 将返回结果赋给msg,调用下载方法时同时发消息更新进度条
mHandler.sendMessage(message);
// 通过Handler传递msg
}
}.start();
}
private
void
btn2Click()
// 点击更新，圆形进度条转动,3秒后更新完成，进度条消失
{
mProgress_yuan.setVisibility(View.VISIBLE);
new
Thread()
{
@Override
public
void
run()
{
try
{
Thread.sleep(
3000
);
String str = update();
//Message msg = mHandler.obtainMessage(what, obj)
//下面部分可以采用上面的方法优化
Message msg =
new
Message();
msg.what = MSG_WHAT_UPDATE;
msg.obj = str;
mHandler.sendMessage(msg);
}
catch
(InterruptedException e)
{
e.printStackTrace();
}
}
}.start();
}
private
Data download()
{
for
(
int
i =
0
; i <
10
; i++)
// 模拟下载进度过程
{
//Message msg = new Message();
Message msg = mHandler.obtainMessage();
//从系统的资源池获取复用msg，避免重复创建msg对象
msg.what = MSG_WHAT_PROGRESS;
msg.arg1 = i *
10
;
mHandler.sendMessage(msg);
// 每次进度发消息给main线程更新进度条
try
{
Thread.sleep(
1000
);
// 10秒后下载完成
}
catch
(InterruptedException e)
{
e.printStackTrace();
}
}
Data data =
new
Data(
"下载完成!"
,
12
);
return
data;
}
private
String update()
{
return
"更新完成!"
;
}
class
Data
{
String name;
int
num;
public
Data(String name,
int
num)
{
super
();
this
.name = name;
this
.num = num;
}
@Override
public
String toString()
{
return
"data [name="
+ name +
", num="
+ num +
"]"
;
}
}
}
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本文转自 glblong 51CTO博客，原文链接：http://blog.51cto.com/glblong/1206262，如需转载请自行联系原作者
