iOS 创建Label 提示“已成功下载”

<p class="p1"><span class="s1">    </span><span class="s2">//1.</span><span class="s3">添加</span><span class="s2">Label</span></p><p class="p2"><span class="s2">    </span><span class="s4">UILabel</span><span class="s2"> *label = [[</span><span class="s4">UILabel</span><span class="s2"> </span><span class="s5">alloc</span><span class="s2">]</span><span class="s5">init</span><span class="s2">];</span></p><p class="p2"><span class="s2">    label.</span><span class="s4">text</span><span class="s2"> = [</span><span class="s4">NSString</span><span class="s2"> </span><span class="s5">stringWithFormat</span><span class="s2">:</span><span class="s6">@"</span><span class="s7">成功下载</span><span class="s6">%@"</span><span class="s2">,cell.</span><span class="s8">app</span><span class="s2">.</span><span class="s8">name</span><span class="s2">];</span></p><p class="p3"><span class="s1">    label.</span><span class="s4">textAlignment</span><span class="s1"> = </span><span class="s2">NSTextAlignmentCenter</span><span class="s1">;</span></p><p class="p2"><span class="s2">    label.</span><span class="s4">font</span><span class="s2"> = [</span><span class="s4">UIFont</span><span class="s2"> </span><span class="s5">systemFontOfSize</span><span class="s2">:</span><span class="s9">12</span><span class="s2">];</span></p><p class="p2"><span class="s2">    label.</span><span class="s4">textColor</span><span class="s2"> = [</span><span class="s4">UIColor</span><span class="s2"> </span><span class="s5">whiteColor</span><span class="s2">];</span></p><p class="p4"><span class="s1">    label.</span><span class="s2">backgroundColor</span><span class="s1"> = [</span><span class="s2">UIColor</span><span class="s1"> </span><span class="s5">blackColor</span><span class="s1">];</span></p><p class="p2"><span class="s2">    label.</span><span class="s4">frame</span><span class="s2"> = </span><span class="s5">CGRectMake</span><span class="s2">(</span><span class="s9">0</span><span class="s2">, </span><span class="s9">0</span><span class="s2">, </span><span class="s9">150</span><span class="s2">, </span><span class="s9">25</span><span class="s2">);</span></p><p class="p4"><span class="s1">    label.</span><span class="s2">center</span><span class="s1"> = </span><span class="s5">CGPointMake</span><span class="s1">( </span><span class="s10">self</span><span class="s1">.</span><span class="s2">view</span><span class="s1">.</span><span class="s2">bounds</span><span class="s1">.</span><span class="s2">size</span><span class="s1">.</span><span class="s2">width</span><span class="s1">*</span><span class="s9">0.5</span><span class="s1">,  </span><span class="s10">self</span><span class="s1">.</span><span class="s2">view</span><span class="s1">.</span><span class="s2">bounds</span><span class="s1">.</span><span class="s2">size</span><span class="s1">.</span><span class="s2">height</span><span class="s1">*</span><span class="s9">0.5</span><span class="s1">);</span></p><p class="p2"><span class="s2">    label.</span><span class="s4">alpha</span><span class="s2"> = </span><span class="s9">0.0</span><span class="s2">;</span></p><p class="p4"><span class="s1">    label.</span><span class="s2">layer</span><span class="s1">.</span><span class="s2">cornerRadius</span><span class="s1"> = </span><span class="s9">5</span><span class="s1">;</span></p><p class="p2"><span class="s2">    label.</span><span class="s4">clipsToBounds</span><span class="s2"> = </span><span class="s10">YES</span><span class="s2">;</span></p><p class="p2"><span class="s2">    [</span><span class="s10">self</span><span class="s2">.</span><span class="s4">view</span><span class="s2"> </span><span class="s5">addSubview</span><span class="s2">:label];</span></p><p class="p5"><span class="s2">    </span></p><p class="p1"><span class="s1">    </span><span class="s2">//2.</span><span class="s3">动画</span></p><p class="p3"><span class="s1">    [</span><span class="s4">UIView</span><span class="s1"> </span><span class="s2">animateWithDuration</span><span class="s1">:</span><span class="s9">0.5</span><span class="s1"> </span><span class="s2">animations</span><span class="s1">:^{</span></p><p class="p2"><span class="s2">        label.</span><span class="s4">alpha</span><span class="s2"> = </span><span class="s9">0.5</span><span class="s2">;</span></p><p class="p2"><span class="s2">    } </span><span class="s5">completion</span><span class="s2">:^(</span><span class="s10">BOOL</span><span class="s2"> finished) {</span></p><p class="p3"><span class="s1">        [</span><span class="s4">UIView</span><span class="s1"> </span><span class="s2">animateWithDuration</span><span class="s1">:</span><span class="s9">0.5</span><span class="s1"> </span><span class="s2">delay</span><span class="s1">:</span><span class="s9">0.5</span><span class="s1"> </span><span class="s2">options</span><span class="s1">:</span><span class="s2">UIViewAnimationOptionCurveLinear</span><span class="s1"> </span><span class="s2">animations</span><span class="s1">:^{</span></p><p class="p2"><span class="s2">            label.</span><span class="s4">alpha</span><span class="s2"> = </span><span class="s9">0.0</span><span class="s2">;</span></p><p class="p2"><span class="s2">        } </span><span class="s5">completion</span><span class="s2">:^(</span><span class="s10">BOOL</span><span class="s2"> finished) {</span></p><p class="p2"><span class="s2">            [label </span><span class="s5">removeFromSuperview</span><span class="s2">];</span></p><p class="p2"><span class="s2">        }];</span></p><p class="p2"><span class="s2">    }];</span></p>